(Topic ID: 153565)

TerryB's Guide to Repairing Battery Damage

By terryb

3 years ago

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    #1 3 years ago

    This article has been replaced by the following updated and complete article.


    If you're curious as to why, just read on. If you're not interested in the drama, just follow the link above.

    I see a lot of CPU boards where battery damage is not being treated properly and as a result the alkali continues to eat away at the copper on the board until the board craps out (due to the alkaline damage) and it's sent out for repair (often after being damaged further in an effort to repair it).

    Friendly Reminder: Get the batteries off the CPU board!

    If a board has minor leakage then a flush with vinegar/water/alcohol is good enough. If a board has moderate to severe damage, it requires an involved process, including removing components for proper cleaning and evaluation of the damage. The key is knowing what to look for and how to properly clean and repair the board.

    I should mention first though that moderate to severe alkaline damage is best left to the pro's. You can be assured you will find a lot more damage after removing components. What compounds the issue is the alkali will get under the copper (traces and pads) and eat away at the adhesive that bonds them to the board.

    Even for an experienced solderer it is difficult to work on an alkaline damaged board without lifting a trace or pad--since they're barely hanging on to begin with. And it's worse yet if previous work was done on the board.

    The board below has minor alkaline damage. It is limited to the one small area, and below the batteries the solder joints are still shiny and there are no dark spots showing through the solder mask. In this case properly flushing the board (vinegar/water/alcohol) is sufficient.


    The board below has moderate to severe alkaline damage. While some areas are rather obvious (the damaged components and the solder mask at the bottom of the board) other parts, like the dull solder joints and the dark spots showing through the solder mask, are not. All of that damage needs to be removed and simply flushing the board is not enough. It will require both chemical and mechanical cleaning.


    The board below has alkali (the white powder) that was hidden until J212 was removed. It is unlikely the alkali would have been neutralized by flushing the board and this is why components need to be removed in order to properly clean and evaluate the damage.


    #2 3 years ago

    Prepping the Board for Cleaning

    Before flushing the board there's a couple of things we need to do first.

    Any socketed chip's that will get wet during the flushing process need to be removed. In the case of a WPC CPU board you can usually get away with leaving any chips above the batteries in place if you're careful while cleaning. While you've got the chips out inspect the lower part of the lead for corrosion. If there is any corrosion you need to clean or toss the chip and replace the socket since it likely is corroded internally.

    While we could do this after the flush, I always remove the battery holder and remove any sockets, chips and connectors where I want to inspect the damage and suspect I will need to physically clean the are.

    Note: When desoldering a board with alkaline damage you always want to clean the joints with a fiberglass pen and add flux. It is also common for the solder joints to have been eaten away and be low on solder. In that case you will need to add some solder prior to desoldering.

    I'm not going to go in-depth on the soldering techniques, but do suggest you review my soldering guide, which also covers advanced repairs like jumpers, stitches and eyelets--which will all likely be needed.


    So the big question at this point is which components should be removed. Alkaline damage will travel down from the point of leakage and will often spread out in an upside down V as it progresses. Any sockets, chips or connectors that have corrosion on the pins or brown spots in the surrounding solder mask should be removed. We will worry about dual-lead components later.

    In the last board in the post above the left battery leaked and the alkali traveled down the left side of the board. So I removed J212, J205 and the chips above them, but below the battery holder. In the image below I've already done some cleaning and you can see where the right battery leaked and how the damage spread as it moved down.


    I did remove all of the connectors but there was no alkali damage under the left and center ones.

    One important thing to note is the damage to this board didn't happen overnight. The longer you let a board sit with alkali on it, the more the damage spreads and the bigger the process to repair. So if you swap out a CPU board with battery damage and throw the old one on a shelf, at least take the time to flush the board even if you do nothing else. Someone later on will appreciate it.

    #3 3 years ago

    Importance of Removing all Alkali

    One more thing before we get into the chemical cleaning of the board. If you've never seen it this may surprise you, but alkali will completely eat through a copper trace if left untreated. And when the alkali is under the solder mask it requires mechanical cleaning, which we'll cover later.

    Another thing to understand about alkali is it does not always show up as a white powder. Depending on the stage it is in it can be completely invisible. That is why we look for the results of alkili damage (see the resistor pads in the second image) and even with that approach you can miss the early stages of alkali damage.

    Your best friend when evaluating battery damage is a magnifying glass or microscope so you can catch the damage as early as possible. To he honest, once you see it, you're too late. Not that it can't be fixed, but it's a lot harder.

    The ground plane in the image below should be about a 1/4" longer and the part that is lifted would turn into copper dust as you touched it. You might also correctly guess this is why traces lift so easily on a battery damaged board. This one lifted without heat being applied. You will also note an inductor that needs to be replaced in the photo.

    I'll have more examples of this as we proceed.



    #4 3 years ago

    Thanks Terry for another great thread! I'm looking forward to all in this series.

    #5 3 years ago

    Neutralizing Alkali

    Everyone has their own little preferences on neutralizing alkaline damage, but they all include (or should) the following three steps.

    1. Neutralize alkali with vinegar.
    2. Flush with water.
    3. Flush with alcohol.

    I use a baking pan (wive's love when you use their kitchen utensils for your projects) to catch the fluids and place a piece of wood under the end I want to keep dry so the board is at a slight angle. A fairly stiff ESD safe brush and a syringe or squeeze bulb will also come in handy.

    During the vinegar stage you want to give it enough time to completely neutralize the alkali. I will spend 3-5 minutes cleaning both sides of the board. Use a syringe or bulb and make sure you get vinegar under any chips and sockets. While the board is soaking you want to scrub the board as this helps loosen and remove the alkali. Keep the board wet as you are working so the vinegar has time to complete the neutralization process.

    I've seen people recommend you dilute the vinegar with water, but you really want if full strength.

    While it is best to use distilled water, tap water is acceptable for the second step. Since all we're doing in this phase is flushing off the vinegar you can move along more quickly and don't need to use a brush. You do want to use a syringe or bulb to get under sockets and chips though.

    The reason our last flush is with alcohol (use 91% or higher) is that it will displace water. Again, no brush needed and make sure you get under any components.

    Once you're done use some canned air or an air compressor to remove any remaining liquid from the board. You will want to do this from a couple of different angles and make sure you get under the components. We could let it air dry, but this is faster.

    #6 3 years ago

    Mechanical Cleaning

    Now that we have the surface alkali neutralized we need to expose any that has gotten under the solder mask. If we don't it will continue to eat away at the copper. Also while we have removed the surface alkali there is still corrosion on the joints which needs to be removed. It is important this is done before we proceed or it will be extremely difficult to reflow or solder any of the dual-lead components.

    The following two images are after chemically cleaning the board.

    In the first image you can see where the alkali has eaten into the board at U20. There are also several damaged traces and through-holes. The trace circled in red was intact, but lifted from the board, and when I prodded it with a solder pick it broke. In addition the area above circled in red has cold solder joints from the alkaline damage.

    I also circled some of the areas where the alkali has gotten under the solder mask.

    In the second image you can see damage to the ground plane and corroded pads where the connector was removed. If these pads are not properly cleaned up solder will never properly flow through the hole and provide a good connection.


    In addition to exposing any alkaline damage under the solder mask during physical cleaning we also need to expose any traces/pads we will be working on or that are suspect.

    #7 3 years ago

    To be honest there's a bit I disagree with here.

    I've been dealing with battery corrosion for 20 years. I've tried everything. The first thing I would like to say is that using an acid (vinegar or mustard which is more controllable) to neutralize the alkaline in my experience does not effect the outcome, it only makes you feel better. In the big picture and in the end it really has no effect on much of anything in my experience. I'm sorry but just from my work and many years of doing this, that's the bottom line. Go ahead and do it if you want, but it's not a silver bullet fix. In the end it seems to have little to no impact on anything, in my experience.

    The key to dealing with corrosion is getting it off the board and then sealing the area. There are a lot of different ways to remove the corrosion. I find personally the most effective way in the case of large areas is bead blasting. There really isn't any better way to do it. For small areas I won't use bead blasting because it's just not time efficient. But for large areas nothing beats it.

    Corrosion can happen in a couple different ways. Basically batteries can leak and effect a small area. Or they can Out gas affecting extremely large areas. Bead blasting works very well in large areas when batteries have out gassed. Sanding or fiber pens work great in smaller areas.

    One big problem with large area corrosion is that is simply not cost-effective to have to remove everything to deal with the corrosion. The area is just too large and will require too many parts to be removed to effectively deal with it. This is where bead blasting works great. Bead blasting does take practice though. You can't go too heavy or too long you have to know what is the correct air pressure to make it right. It is easy to blow off traces with the bead blaster if you were working on boards say 1988 or newer.

    After the corrosion is dealt with and traces rebuilt that were removed during the cleaning process, the board must be sealed. If you do not do this the corrosion will return and will return with a vengeance. It doesn't matter if you've treated the board with an acid like vinegar. The corrosion will come back if the board is not sealed. Personally I use clear lacquer to do this. But pretty much any sort of *thin* coating that seals out oxygen will work fine.

    I work on a lot of boards that have been repaired by other "professionals". Frankly there are very few people who deal with corrosion properly. I often get boards repaired by name brand repair people in which the corrosion is just embarrassingly bad. If your repair guy does not have a bead blaster I suggest you find somebody else to deal with the corrosion. Is a bead blaster always needed? No, but why have someone repair a board that does not have all tools needed at their disposal.

    #8 3 years ago

    Here is in example of a board that has been bead blasted. The area was fairly large but was not too invasive. But notice that the ground plane from the top right of the board all the way down that side, along the bottom, and halfway up the left side all needed to be dealt with. It would never be effective to use a fiber pen or Sanding to deal with an area this large. this whole board was treated in under five minutes with a Bead blaster. Any damaged components were replaced such as sockets or glass diodes, and the board sealed with clear lacquer. This work was done five years ago. And it still looks like the day it was treated. Vinegar was not used in this process. When you get your board back from a professional repair facility that has dealt with corrosion properly, this is how it should look. And it should stay looking like this for many many years.


    #9 3 years ago

    Here is a William system 11 board that had battery corrosion from outgassing. The entire board was affected by this. There was corrosion from the lower left corner all the way to the upper right special solenoid area. And to make things worse, the special solenoid area had started on fire and burned a hole through the board. This area was covered in black carbon. Tip of the day... Black carbon on your board is conductive. It must be removed. Again you could use a little fiber pen and some sandpaper to do this, but the most effective way to deal with an entire boards worth of corrosion and black carbon is bead blasting. Below is the board after the entire thing was bead blasted. This took about five minutes worth of work. The board was then sealed. Note this board went to a professional repair service, twice! The corrosion was never effectively dealt with (that is they used a vinegar bath only thinking that would stop the corrosion). How can anyone expect a board to stay working if you don't properly deal with the corrosion?

    The problem with the outgassing is the large area effected on this board. There is no way you could remove components sand off the corrosion and then put everything back. It would cost more than the board is worth in both time and parts. The only way to deal with this is bead blasting.


    #10 3 years ago

    Remember corrosion is like a cancer. If you don't remove it and seal it, it will come back. It may take a month it may take years. But why not just do it and do it right the first time. Again I don't see vinegar or mustard or any of the neutralizing acids as helping to this end. If it makes you feel better go ahead, i guess there's not a lot of downside, but I just don't see it as a viable solution to dealing with corrosion. It is so 1990s and we now have better ways to do this, ways that actually work and keep your board working for an indefinite period of time.

    #11 3 years ago

    Clay, do you take in boards for repair currently?

    #12 3 years ago

    I normally don't talk much about my experience, but in this case I guess I will.

    I have a EE (although my career was in manufacturing and field service) and have been dealing with corrosion on boards for 40 years. Although I will be the first to admit the number of years, or the degree, is not the important issue. My experience is in medical (MRI, Cat-Scan, X-Ray, etc) and aviation electronics where the standards (and training) are a little bit higher than in pinball (no insult to other pinball technicians intended). I've manged a multi-million dollar board repair/rework facility and on average probably spent 4 weeks a year (for twenty years) at seminars and training sessions.

    So you can believe whatever you want clay, and I'm not going to waste my time asking for your sources since every time I do you never provide any proof other than to tell me about your years of experience. As far as your feelings on alkaline, I can assure you that you are in disagreement with the IPC and the entire electronics industry. There is no way that bead blasting, which I was going to cover next--although with proper techniques rather than what you have previously recommended, will get into every nook and cranny and get rid of every bit of alkali. Just not possible.

    We both know this isn't about doing something the right way, it's about your ego since the last time I checked you are not the arbiter of what is and is not correct when working with electronics.

    #13 3 years ago

    You need to figure out the labour & parts cost. I would say for the average guy, it's now better to walk away, & buy a new board. Back 20 years when I got in the hobby, you would spend many hours trying to repair electronic boards. There wasn't really a affordable alternative. Now many suppliers are making superior replacement boards. Even if you do repair the board & get it working, it's 20+ years old.

    #14 3 years ago

    The problem with chemically treating corrosion is a deep one. It cannot be effectively dealt with by the average person. If chemical neutralization of alkaline damaged boards is your goal you need to know several things.

    First you need to know the basic pH of the alkaline. Because if you were going to neutralize it your acid needs to be of a similar quality. Nobody here can do chemical analysis of the MPU board to determine exactly what strength of acid will properly neutralize the base.

    The second thing needs to be dealt with is how long to actually neutralize it. Again without knowing your pH numbers this again is just guesswork.

    What happens in most situations is the alkaline is either under treated or over treated. In either case the result is a continuation of corrosion. This is not an effective way for anybody in the pinball world to really deal with corrosion.

    This is why I tell people that using chemicals to try and neutralize corrosion is not a winning scenario. If it makes you feel better go right ahead. But in the end it is not going to really do much.

    #15 3 years ago
    Quoted from cfh:

    The problem with chemically treating corrosion is a deep one. It cannot be effectively dealt with by the average person. If chemical neutralization of alkaline damaged boards is your goal you need to know several things.
    First you need to know the basic pH of the alkaline. Because if you were going to neutralize it your acid it needs to be of a similar quality. Nobody here can do chemical analysis of the MPU board to determine exactly what strength of acid will properly neutralize the base.
    The second thing needs to be dealt with is how long to actually neutralize it. Again without knowing your pH numbers this again is just guesswork.
    What happens in most situations is the alkaline is either under treated or over treated. In either case the result is a continuation of corrosion. This is not an effective way for anybody in the pinball world to really deal with corrosion.
    This is why I tell people that using chemicals to try and neutralize corrosion is not a winning scenario. If it makes you feel better go right ahead. But in the end it is not going to really do much.

    I showed that post to a buddy of mine with a Doctorate in Chemistry and he laughed for about 10 minutes and then told me to look up the Dunning–Kruger effect.

    #17 3 years ago

    Removing all corroded components and physically removing all corrosion down to clean copper via abrasion is the way to go. Once you have clean copper you can solder coat the traces. If you take it that far, PH doesnt matter as far as I am concerned

    Splashing vinegar on corroded traces does nothing... you need to physically take off the corrosion until it is clean copper that is willing to take solder with no issues wetting.


    #18 3 years ago

    Writing these guides or any how-to takes an incredible amount of work. If you don't agree, say your bit if you must (keep it short!) and start a new thread with your view. Don't completely derail a thread that has and will continue to have good information. Terry, I hope you take your posts and start a new thread that doesn't have such dumping. Clay, I hope you start your own thread where you can share your 20 years of experience.

    #19 3 years ago

    I agree with Andrew. The corrosion has to be removed. How that is done is up to the person involved. but for large areas bead blasting is the most time constructive approach. For small areas sandpaper and/or fiber pens works. And yes parts have to be removed if the corrosion is under the parts. That would apply to sanding, pens, or bead blasting.

    The key to bead blasting is just how much area can be covered, and covered well. It also gives a very professional look to the work when you're done. It is also much more effective at removing the corrosion.

    Again if splashing vinegar on your board makes you feel better, as Andrew said too, go for it. But it's not a silver bullet and it won't arrest the corrosion. In a lot of cases it's a waste of time and makes your board smell and liquid gets under chips and things and must be dried.

    The key is after you have dealt with the corrosion, a "conformity coating" must be re-applied. This seals out the air and will stop any future corrosion. Personally I use a thin coating of clear lacquer for this. Lacquer is also solder-able, so after spraying I can still solder the board without any issues. If you skip this step the corrosion *will* come back. It doesn't matter if you used neutralization chemicals or not, it's coming back.

    Note some people use solder on traces (Andrew for example) to seal them. I personally don't like that approach as it's time consuming, and easy to miss an area or a trace. I also don't like how it looks. A spray coating is much more efficient, easier and quicker to apply, and covers entire areas so you don't miss anything. But i've seen Andrew's work and it does look good. If that works for him, awesome. But i think he spends way too much time doing that personally. It does have the advantage that new solder won't stick to a trace unless it's completely free of corrosion. So in that regard it's a nice "double check" for corrosion removal.

    Another point about the coating is if corrosion is not 100% removed, the coating seals it from air, and will arrest further corrosion. Because frankly it's difficult to remove corrosion (using sand paper/pens/blasting) 100%. The coating is absolutely required if you don't want the board to re-corrode.

    But this whole thing with vinegar or mustard (which is a lot more controllable and easier to work with) to "neutralize" corrosion, i've personally found it to be a useless step. I think it gives people the idea they are helping, when in fact, it's just not doing anything.

    As Joel Cook used to say, "pickle the board in a glass jar filled with vinegar for a week, that'll do the trick!" I mean he was joking, but to that end, he was right about using chemicals to arrest corrosion. It just doesn't help, and you don't really know if you've done it enough or too much.

    #20 3 years ago

    I apologize if my posts came off dis-respectful, that was not my intent. I am only relaying my 20+ years of dealing with battery corrosion on pinball boards. Obviously one's mileage will vary. I do over 500 game repairs a year, and have done that consistently for the last 10+ years. And I work at a pinball museum keeping 300 games running. So there's a lot of data points here. Again if someone feels chemicals will add to arresting corrosion, then go for it. But in my experience it's just a placebo effect and has no impact on arresting corrosion, just creates more work with chemicals, and gives false hope.

    #21 3 years ago

    When I got into the hobby in 2008 there weren't really any good guides on properly dealing with corrosion, just some discussion on RGP and a few websites.. but they all seem to have missed the step of "sealing" the board, which wasn't something I really saw people pushing the criticality of until a year or two later. Anyway nice seeing a guide like this being created to help others realize the proper way of doing things so they can get it right the first time!

    What's baffled me in recent years is reworked board prices have continued to go up across the board. $110-130 for reworked Bally-35 boards, some of the more expensive include nvram. Brand new Allteks are $200, already have nvram built-in along with some other bells-and-whistles. The prices keep inching up on the used reworked boards and yet the new board prices remain the same. At some point, you'd think people would realize it's probably just about as-cheap to sell the old board (since people will often pay $40-60 for a board that can be fixed up) and be in about the same place financially, but further ahead in many other ways.

    #22 3 years ago
    Quoted from cfh:

    I apologize if my posts came off dis-respectful, that was not my intent.

    as lyonsden said, you should just edit out your posts and take them to your own HOW TO thread. There are different ways to get a job done. Sometimes multiple ways to get to the same end point. Terry puts alot of effort into these threads and they ae often some of the most favorited threads on the forum. It is actually dis-respectful to come in here in the manner that you did. A nice couter point which links to a "how to" thread of your own with your process would be much appreciated by most I would assume. I know I would like to see your actual process, the tips for bead blasting, and nice photos showing it off in a separate thread.

    Much like I enjoy seeing how Terry does things and his GREAT tutorial thread with photos and how tos.

    #23 3 years ago
    Quoted from acebathound:

    When I got into the hobby in 2008 there weren't really any good guides on properly dealing with corrosion, just some discussion on RGP and a few websites.. but they all seem to have missed the step of "sealing" the board, which wasn't something I really saw people pushing the criticality of until a year or two later. Anyway nice seeing a guide like this being created to help others realize the proper way of doing things so they can get it right the first time!
    What's baffled me in recent years is reworked board prices have continued to go up.. and even if that's partially due to including nvram with them -- new replacement boards often have nvram included (Alltek for instance). If you look at eBay history, people are paying $90 for Bally-35 boards with "small amount of corrosion, but fully functional" -- $110-130 for boards that were reworked. Some of the more expensive ones include nvram. For $200, you can put in a brand new Alltek that has never seen *ANY* corrosion & comes with nvram and some other fancy bells-and-whistles.. then sell the old board and be in *almost* the same place. Used boards with corrosion go for $40-50 on eBay often enough. I get some people can't be bothered with selling and shipping anything.. and some people want "original" boards and all that.. but as prices of reworked boards continue to rise and get near what a new replacement would cost, it's making more and more sense to just buy NEW. Then you don't have to worry about who worked on your board and to what level the corrosion was dealt with.
    I keep thinking there's a limit to how much can be charged for reworked boards, yet keep seeing prices pushed.. and am just surprised they still sell. But then again, some people just don't look at the numbers in that kind of detail and only at the purchase price. Happens with machines too.. "I paid $300 for that machine" and then they had to put another $500 in it to get it up and running, but the number that sticks is $300..

    Oh ace.... the shots never stop do they =D

    Part of it is supply and demand.

    Three - five years ago i was buying boxes of 20+ MPUs no problem that had rebuild able corrosion on it. I was paying ten bucks a board and 15 out of 20 i could fix up. Sources like that has been drying up, it is just that much harder to find good cores than it was 4 years ago.... price reflects that. I haven't raised my mail and return prices, but i got way more picky about not working on crap boards.

    NVRAM is great.... i can offer it up as an upcharge and everyone always says yes... why would they say no tho... no reason to funk with batteries anyways anymore.

    #24 3 years ago
    Quoted from barakandl:

    Oh ace.... the shots never stop do they =D
    Part of it is supply and demand.
    Three - five years ago i was buying boxes of 20+ MPUs no problem that had rebuild able corrosion on it. I was paying ten bucks a board and 15 out of 20 i could fix up. Sources like that has been drying up, it is just that much harder to find good cores than it was 4 years ago.... price reflects that. I haven't raised my mail and return prices, but i got way more picky about not working on crap boards.
    NVRAM is great.... i can offer it up as an upcharge and everyone always says yes... why would they say no tho... no reason to funk with batteries anyways anymore.

    It's not a shot at you Andrew, sorry you feel that way but take it up in PM if you want to discuss further. Just making a general observation of pricing I've seen from *many* sellers on eBay, etc. As they continue to rise and near "new board" prices it seems like it'd make more sense just to go with a new board in some cases.

    Anyway, back to the topic at hand.. this type of guide is great because there will always be people DIY'ing to save money and/or buying reworked boards. The more info that's out there on proper technique/methods the more likely the quality of what's being done by everyone (including Joe Homeowner) will get better as well... and the more likely people will know what to look out for in boards they're purchasing.

    Nice job Terry, keep it coming!

    #25 3 years ago
    Quoted from Whysnow:

    as lyonsden said, you should just edit out your posts and take them to your own HOW TO thread. There are different ways to get a job done. Sometimes multiple ways to get to the same end point. Terry puts alot of effort into these threads and they ae often some of the most favorited threads on the forum.

    I think this approach makes a lot of sense and would be the best for everyone involved. I would love to see Clay's method here as a counter point but the contents shouldn't be injected in the middle of Terry still trying to explain his own approach.

    Perhaps the best solution here is a combination of both methods. Beads to remove everything that can be physically removed first and then a vinegar treatment to clean up anything left behind.


    #26 3 years ago

    That's kind of the point behind bead blasting. After blasting there really isn't any corrosion left behind, so the use of chemicals becomes even less important. Just in my experience I've seen and tried to use chemical neutralization. It never does what people think it should. The corrosion always comes back and often very quickly. Sometimes the board just ends up worse too. there so many variables in what strength of acid to use and how long. It just becomes guesswork, and usually frankly you guess wrong. It's a waste of time in my eye, there's just better ways to deal with the corrosion then using any sort of liquid chemicals on the board. But if you think it's going to work, that is the placebo effect, then go for it. But my statements hold where I think chemical neutralization is not a workable solution to corrosion.

    #27 3 years ago
    Quoted from cfh:

    That's kind of the point behind bead blasting.

    PLEASE start a "how to" thread for your method of bead blasting and repair. I would love to see it.

    #28 3 years ago
    Quoted from cfh:

    That's kind of the point behind bead blasting...~snip~blockquote>

    Most of your points are economic or time based. These are virtually negligible for the hobbyist. These points may be important to you, but for many they are not.

    Instead of polluting a thread repeatedly with your dissenting opinions, why don't you put up a link to somewhere people can pay you for your invaluable version of this information. You have more than made your point and your further input will just be redundant.

    Good to see the old Clay back

    #29 3 years ago

    Here are some i made years back. I like to think my soldering techniques have improved since these posts. I also do no washing of board until I have completed the job. I wash the dirt off with dish soap. Cut the flux with naphtha.



    #30 3 years ago

    I've calmed down a little bit (just a little).

    Firstly, I have no issue whatsoever with people asking questions or having a discussion about different opinions. In fact that's how you learn and become more knowledgeable. On the other hand, I'll be damned if I'm going to let two self-professed know-it-alls who don't have 1/100 the professional board repair experience I have--and have probably never attended a professional electronics seminar, training session or conference where things like this are discussed--call me full of shit.

    As I said I've just calmed down a little bit. Although I do still get a laugh every time I think about Clay's suggestion that mustard is better than vinegar in neutralizing alkaline damage and picture someone pushing the mustard under a chip with a toothpick (or maybe a cocktail wienie). I will be telling that story at the next conference I speak at.

    I can confidently state that all professional board repair/rework facilities use acid to neutralize base damage on a board and use a base to neutralize acid damage on a board (as is recommended by the IPC). Of course they don't use vinegar (or mustard), they pay about 10 times as much for something with roughly the same pH. I figured since you have to buy the professional solution by the barrel, most hobbyists would prefer an equivalent solution.

    For those hobbyists who are now totally confused about chemically neutralizing alkaline damage let me explain the fallacies in the previous assertions. After this I'm done with the thread and when I have time will post the information on my website where people can have respectful discussions.

    For anyone interested there's already an article on media blasting on my free website.


    1. You will never get glass bead media into all the nooks and crannies where alkili hide since the beads are thousands of times larger than an alkali molecule. Have a look at the inductor on a WPC CPU board (shown below) and explain to me how the media gets in-between the coils of wire and neutralizes the alkali that have seeped in there. The same is true all over the board.
    2. If you do not chemically clean the board then you will need to remove all of the chips, sockets and connectors. Because if even one has some alkali under it you're screwed since clearly bead blasting will not get under components.
    3. If you bead blast before you neutralize the alkali that is "above the surface" you are in fact spreading the alkali molecules around the board and contaminating other areas. At this point you need to clean the entire board, not just part of it.
    4. If you look at the photos I've posted above you can see where the alkali has gotten under the solder mask. Where else do you think it's hiding that you can't see?

    Now let's talk about bead blasting.

    1. Most hobbyists aren't going to bead blast their boards. Therefore a combination of chemical and physical (sandpaper or whatever) is needed. In fact if Clay would have shut-up and just listened he would have found that I do a three step process: chemically neutralize the damage, bead blast the board and chemically neutralize it again.
    2. According to a study done by NASA, glass beads create an electro-static discharge of -1,764 to -2,097 volts during media blasting. This was deemed to be "unacceptable levels of surface voltages." In other words you are potentially damaging components. Therefore you really should use an ESD safe micro-blaster. The reason for the micro-blaster as compared to using a sand-blasting rig, which is a serious no-no by the way, is so you can control and minimize the media hitting sensitive components (CMOS and other chips for example). You also want to prevent damage to the component packages.
    3. Even the board repair guys aren't going to spend several thousand dollars for an ESD micro-blaster. Although I do have a reasonably priced (home-made) recommendation in my media blasting article above.
    4. Since you should be doing controlled media blasting and not bombarding chips you are not going to remove all alkali. How are you going to get under all of the resistors, for example, without damaging the coating on the resistor. The answer is you can't unless you lightly bead blast in which case you're probably not getting all of the alkali. See the image below where I damaged a resistor package while bead blasting.
    5. Any type of physical cleaning requires you to see where the damage is. As I have previously stated alkali is not always a visible white powder or displayed by dark spots under the solder mask. In other words if you're relying on the physical approach you would have to remove every bit of solder mask on the lower part of the board because any of it could be contaminated.
    6. FYI Clay, glass bead are so 1980's. Most board repair/rework facilities are now using wheat starch.

    Rather than tell everyone they're an idiot if they don't do it my way, I'll leave it up to each of you to make up your own minds based on the information provided.

    This is how you have a discussion Clay, rather than making hyperbolic, ill-informed statements and calling people out. Of course as I said before this isn't about neutralizing alkaline damage, it's about your ego.

    This thread is a perfect example of why Pinside can't have nice things.



    #31 3 years ago

    Thanks for posting this for all the folks who are trying to address alkaline corrosion. Much appreciated.

    I was hoping it would be a continuous stream of information but it's not surprising that you were interrupted.

    @Clay...the fellow above that suggested you move your opinion to another thread had a good idea.

    @Terry...The Wiki has scattered info on abating alkaline damage. Would you consider adding your guide to the "General for all games" section?

    Thanks again.
    Chris Hibler - CARGPB #31
    http://www.PinWiki.com - The new place for pinball repair info

    #32 3 years ago

    Yeah, don't let Cley rile you up.

    He always pops up with crazy **facts** like wax does not protect surfaces, or that it will melt your ramps and posts.

    Ignore him so he can get back to putting his guides online again.

    #33 3 years ago

    of course parts have to be removed to deal with corrosion under the parts. but sometimes that just isn't possible on boards that have large outgassing damage (like that system11 board shown above.) if you removed all the parts, and then sanded, and then replaced, you would have a 40 hour long $1000 CPU board.

    I get that people think chemical board baths arrest corrosion, but my experiences shows otherwise. But if you feel strongly about, go for it. besides the time element and added work there's not a lot of downside, beside the placebo effect.

    as for bead blasting having static issues, i have found this to not be the case. My general approach is to get the board working, then remove the corrosion (using bead blasting or other techniques.) Other than a ruined glass diode on occasion or a sanded trough/blown off trace, i have not found any static issues with bead blasting.

    my experiences relate directly to pinball board repair. that is, i'm not fixing copy machines or medical equipment. so the experiences are relevant to this forum. I didn't come here insulting anyone. I just said i disagree with the chemical bath, i think it gives false hope and doesn't deliver or do what people expect. I personally gave up with the chemical baths years ago because it just doesn't do anything. but if you feel better doing it versus not, go for it. But it's no silver bullet.

    someone mentioned time. like it or not, time is money. if you have just one board to deal with than maybe it's not a big deal. but there's just so many other things that need done, time is very important (at least to me.) So i'm always looking for better and quicker ways to deal with problems.

    In the end there are different ways to skin the cat. i disagree with some of these ways. it's just my opinion, but it is based in a lot of relevant experiences. take it or leave it, makes no difference to me. i'm just telling you what i've seen in my life, and what has worked, and what has not worked. Yes my ideas are often different. i don't follow the crowd, and i'm always trying to find ways to improve processes. which is why i posted here. i'm sorry if you're offended by my opinions, my intention was to get people thinking about different approaches, and how they work for me (and maybe you too.) this is a thread about battery corrosion, and it seemed very relevant to post my differing ideas here. I didn't come here calling people names and being mean. i came here to tell my experiences and what does and doesn't work (at least for me) in the real world, and that i don't always agree with common convention. I fix pinballs all day long, pretty much from 6am to 11pm every day (though the hours aren't that great on weekends.) i do this stuff a lot, it's real world pinball experience.

    On vid and wax, it's a similar thing. a promise which in the end does not deliver. that's for another discussion, but again that's how i feel about it.

    #34 3 years ago

    A problem I see over and over again in these types of discussions is the tendency to use anecdotal evidence or tribal knowledge rather than data. People cannot agree on what cleaner/wax to use let alone how to approach board repair.

    I will add as a chemist/materials scientist that neutralizing with acid is a sound approach because when you lower the pH of Cu you tend to reduce the oxidation state.

    I will also add that i appreciate both of your efforts and expertise.

    #35 3 years ago

    Clay would you mind describing the test setup and voltage results of your static electricity test?

    #36 3 years ago

    Terry, thank you for continuing this thread. I am really looking forward to it. Clay, you've stated your point over and over again, can you please stop posting in this thread and start another one?

    #37 3 years ago

    Corrosion goes deep down. When you abrasively clean, it can take a bit of scratching off the top to reach clean copper. Splashing vinegar on top of corrosion is doing nothing but make you feel better in the short term.

    All the components need removed, the tracks need abrasively taken to clean copper via sanding, bead blasting, etc... i sand with plumbers type stuff, sometimes that means no traces remain and you need to stitch traces. the clean copper needs tinned. Once the tracks are all recoated in fresh solder and all components replaced, you have done a good job. This means IC sockets too.

    #38 3 years ago

    I agree with Andrew. The true test that you have removed corrosion is that you can solder the traces. If you can't solder a trace, than the corrosion still exists. Using chemicals does not help this cause. Again it's over promise, under deliver type thing, it doesn't do anything to help. This is why i like bead blasting. it takes the least amount of effort to make the traces accept solder. It does *not* beat the corrosion into the traces as someone stated above, in my experience.

    Back 15 years ago when i first got the blaster cabinet, i tried sand in the blaster. Wow that was a mistake. They looked great, but you could not solder the traces. The traces would turn black, meaning all i did was beat the corrosion into the traces. Using ceramic beads doesn't do that.

    So people are now using Soda blasting instead of ceramic beads. Personally i have not tried this. I'm very happy with the ceramic beads, it's been working great. Again again, not even one issue with static. Not one. (Of course i usually remove socket chips before blasting.) I hear soda works well too, would love for someone to post that has used that on corroded boards.

    All i can say is i have a lot of data points on pinball boards using these techniques. Real life experiences. I'm sorry if it runs in the face of what people think is "common knowledge." But it's real pinball life experiences. That's all i can tell ya. After 100s (if not 1000s) of data points, this is what has happened in my experiences.

    another example of this is a game i just re-visited after doing corrosion repair about 4 years ago (bride of pinbot). i had to come back out because at the original repair i used vinegar to try and arrest the corrosion at a guys house (obviously i don't carry a bead blaster in the car.) The corrosion was back a few years later, switch matrix rows out. Again the chemical thing just doesn't help. in this case i took his board home to repair it with the blaster, and coat with a new conformity coating, so it won't re-corrode again.

    with this i won't post any more here. all i was doing is saying that conventional thinking isn't always how it works in the real pinball world. I'm sorry if that's doesn't play well. It's not like there's some agenda and i work for a bead blasting company or a repair shop looking for work. I'm just trying to present ideas and what has worked for me personally in the 1000s of games i've repaired.

    #39 3 years ago
    Quoted from cfh:

    Using chemicals does not help this cause.

    Maybe you just didn't do it 'properely'?


    Dozens of links just like this one say you are quite simply wrong. When you're the only one in the world holding an opinion...maybe it's just that you're mistaken.


    -To clean any leakage of the following battery types, Alkaline, NiCAD and NiMH batteries, use either one tablespoon of boric acid in one gallon of water or a mixture of equal amounts of diluted vinegar or lemon juice with water (50/50 ratio).

    #40 3 years ago

    Some believe that "experience" trumps the laws of chemistry, physics, and mathematics. Some, based on experience, also believe in ghosts, spirits, and aliens. Hard to argue with beliefs.

    #41 3 years ago

    Corrosion goes deep down. Abrasion is needed hands down... You are foolish to think otherwise. Chemical bath is not going get deep down where the corrosion is. If the tracks are not wettable easily by new solder. The corrosion is not cleaned up.

    Clay is right and you are foolish to think otherwise. Real life XP matters. I have repaired probably 500+ different corroded boards. I know what I'm doing and very confident abrasively removing corrosion is more important the chemical neutralizing. If you remove all the corrosion, there is nothing left to neutralize. It is gone. Splashing vinegar on it and calling it a day is half ass approach and not a long term fix. I have boards i did in my games 5+ years ago when i was still somewhat new that i did not seal the copper and now they are corroding over again. Yes i did vinegar them.

    I work with printing equipment. I have seen professional board repair houses send back refurb'd PCBs that look like SHIT. The people doing these boards get paid huge money and sometimes the solder work that comes out is done by what looks like amateurs.

    In fact. I have pictures of what happens when you just splash vinegar on a repair and call it a day. I will have to dig out some good examples from my junk piles.

    #42 3 years ago

    Lots of butt hurting in this thread. Thanks for all the info everyone.

    #43 3 years ago

    I've heard marshmellow fluff does a better job at neutralizing than vinegar.


    #44 3 years ago

    Where did anyone ever say not to sand/bead blast/etc the affected areas? I'm just wondering because that didn't seem to be where this guide was going. There's a section for "Mechanical Cleaning" that would involve exposing the areas -- that comes after the initial neutralizing of affected areas. Then it appears there would be further neutralizing after the mechanical cleaning.. followed by clean-up with alcohol & distilled water, then *likely* finally sealing with conformal coating.. if Terry was able to finish. Nowhere did I see just to brush/rinse affected areas with vinegar and call it a day.

    IMO, if we're arguing about whether chemically neutralizing does anything at all -- then I guess there's no reason to use bromine or chlorine in hot tubs or pools to maintain pH. Good luck with that.

    If the argument is more about having boards last longer with just sanding/bead blasting corrosion and then sealing them.. versus sanding/bead blasting, using vinegar and not sealing.. then okay, boards that are sealed last longer than those that aren't. The BEST solution seemed to be where this guide was going. Do BOTH. Neutralizing/sanding/neutralizing/cleanup/sealing. Why argue with science and then in 5-10 years figure out some boards might have lasted an extra year or two.. or 5.. had the neutralizing step not been skipped.

    Back in 2008 there was no mention of sealing boards at all in many guides / RGP. It was just sand and use vinegar. I missed the "seal the board" step because of that early on when I was fixing up some boards. Now it's a huge deal. Had a *COMPLETE* guide been made back then.. and trickled its way out to the many websites of people doing repairs of their own, etc.. I'm sure many more boards would have been cleaned up correctly & then sealed adequately. I'd trust the guy(s) that are experts at what they do & have worked professionally in the pcb industry or as chemists in getting a correct guide made up for this kind of thing.

    #45 3 years ago

    Thank you all for the inputs. Good reading and learning.

    I've been lucky over the years using DeOxIt to flush away battery leakage and corrosion. Maybe I am being too simple in my approach, but this seems to have alleviated many battery leakage issues for me.

    Having said that, I have yet to encounter a MAJOR leakage as I have seen in these examples.

    My two cents for the day!

    #46 3 years ago
    Quoted from acebathound:

    I've heard marshmellow fluff does a better job at neutralizing than vinegar.

    I just rinse mine down with beer. Goes good with the lock bar.

    #47 3 years ago

    I know that there's science and math behind corrosion ph. But again through my experience, much like Andrews, I just don't see chemical wash as being helpful in any way, shape or form. It gives a false hope that the problem is solved.

    For example, math logic could be used on burnt Williams G.I. connectors. You can take the number of bulbs, multiply times .25, and that'll tell you how many amps is being drawn. Then look at the number amps the connectors are rated. It should be fine the math adds up, it makes sense. And that's why Williams did what they did. But the reality of the situation is it doesn't work and that the gi connectors burn on every Williams game from 1986 to 1999. I'm sorry but the reality of the situation and the actual science and math behind it don't always Play well together. Real world and the math don't always jive. It's a similar situation here. It sounds all cute like splashing some vinegar on there is going to save the day, but in my experience it just doesn't do anything.

    Sorry probably shouldn't have posted this... I broke my promise, I'll shut up...

    #48 3 years ago
    Quoted from cfh:

    Sorry probably shouldn't have posted this... I broke my promise, I'll shut up...

    Time to start the beer method

    #49 3 years ago

    I think there's a lot of knowledge in pinball, and I think it's great that so many people are willing to openly share it. There are techs who don't participate in forums like this, and don't share knowledge. Without share of knowledge, it dies with us.

    I have a lot of practical knowledge from doing, but I have no formal education in this area.

    I've learned at least something from everyone who has posted an opinion in this thread in the past. I don't look at anyone posting here as 'right' or 'wrong'.

    So, I don't know that I agree with the 'start your own thread' thing - it's easier to have an open discussion with multiple opinions in one thread. It helps if everyone checks their ego at the door and the thread can go in a civil direction. I'm not pointing any fingers here. Anyone reading this thread can form their own

    I think there's more than 1 way to skin any cat. I have repaired a significant number of PCBs for a number of people over the last few years, and I turn away boards with large amounts of corrosion. I do this for multiple reasons... including but not limited to...

    1) Cost of repair. I'm not doing this as a volunteer effort. It helps me with my master plan to get out of debt, helps me support my family, and from time to time, supports my hobby. I have a very limited number of hours in any given week to fix pinball boards. A WPC CPU like you're using in this repair guide would be returned un reparied by me. That's not saying it's not repairable - any board is repairable, given enough time - it's not economically repairable. Considering the readily available replacements from Rottendog, Two Bits, or anyone else, you can't spend hours on a CPU board repairing it if you are charging a labor rate. I can't charge a guy $125 to repair an original WPC CPU when they can buy a repro that has never been exposed to the alkaline for $50 more. There are very few exceptions to this rule - a few boards that are not reproduced, or are not available used in reasonable quantities. Those might be worth putting a little more into.

    2) I can't be certain on a repair like that that I'll catch everything. I don't do a repair where I don't give the customer some sort of a warranty. I try hard to get it all, and I hope I got it all, but as alkaline travels through the air, you may never see a bit of it that somehow got under a chip.

    I too have opinions, and have operated as sort of a 'Switzerland' of pinball for years. I try to respect everyone, and I value everyone's opinions. As stated, I've learned from everyone with an opinion here in some format.

    I bought a bead blaster in 2014. Part of this was based upon Clay's advice, but I had also wanted a bead blaster for cleaning up metal parts for vehicles and metal brackets etc for pins for years. So, I figured even if it wasn't useful for PCBs, I would get my moneys worth out of it.

    I've fixed a number of rotten boards where people did the whole 'douche the PCB' with vinegar and water, and there was corrosion under ICs and resistors that may not have been there before. It also may have been there before - obviously I haven't been watching the board since the beginning of time to know for sure. So, I've not been a fan of that method *solely*. IMO, that method solely may buy people some time - but we don't know how much time that is.

    The bead blasting has worked better some times than others for me. I haven't had much luck with WPCs, probably due to lack of finesse. I think I use mine differently than Clay uses his, however. I will blast an area so I can desolder any affected components. I cut the ICs and resistors out, leaving the lead intact, and then blast the board so solder will flow, desolder the components, and then get the traces clean before sealing them. I don't want to send someone a board where the stripes are gone off the resistors, for example. I think if you've blasted a resistor that much, odds are, you've shortened its life. Resistors are cheap.

    My favorite tool for cleaning corrosion is my fiberglass pen. I feel it gives me the most control. You can use a light touch, or a firm touch, and it cleans depending on how firm of a touch you give it. It's aggressive enough to remove the alkaline, but not so abrasive that it instantly burns through traces. Even on a Sys11 where the battery traces are fine under the battery holder.

    I'm playing with Cratex, a rubberized abrasive in stick format, similar to the socket cleaning sticks that PBR and Marco sells. It's a machinists tool that one of my local collector friends/customers brought by for me to check it. It has potential too.

    I know several guys who just use regular ole sandpaper and do a good job. I think that may be a more likely tool for a hobbyist to have in their toolbox, as those are the people who are going to repair a CPU like the one in the pics. Someone who has time to invest in something like that board as a fun side project.

    It's also worth pointing out that pinball boards are not expensive boards. Yes, $200 for a aftermarket CPU seems expensive, but when I say expensive, I mean boards that may cost multiple thousands or even tens of thousands of dollars in a MRI machine or something. I expect the people working on those to have a much higher degree of training, better equipment, etc. If every pinball tech had that level of equipment and experience, none of us would be able to afford the pins!

    So, please keep the open discussion going IMO. But let's keep it civil - and fun!

    #50 3 years ago

    If you guys want some fast chemical neutralizing of battery alkali salts, the product you want is "SnoBol Thick".

    The bench guys at work use it to clean the damage from leaking coin cells in the CNC keypads. Instant pink.

    It's a thick liquid, so it does not run everywhere.

    Sno Bol has a ph of 1 (Mustard has a ph of 5) - so don't leave it on so long that it eats the copper too.

    Rinse with distilled water followed by isopropyl .


    Then you can soda or wheat blast away without worry about spreading the alkali or contaminating reusable blasting media.


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