You can use green nail polish to cover traces back up. Although on that board, you may need to buy out a Mary Kay™ distributorship.

I often see people just splash some vinegar on a corroded board. That really isn't a fix by any stretch! You really need to do what Bob did above to remove it completely.

Now that you have corrosion removed the best fix now would be to coat all that bare copper with a thin layer of solder. If you don't coat the copper it will oxidize and corrosion may somewhat come back in a few years. You can coat the traces and then wipe off extra solder with a damp cloth. If you have a vacuum desoldering gun you can use that to quickly tin your traces. Just gently wipe the tip across the trace adding solder and run the pump. You are left with a nice shiny thin coat of solder. This technique takes some practice.

After all your traces are sealed, you can use green nail polish to help seal and for cosmetics. Just sealing your bare copper with clear or green nail polish is probably good enough too.

Andrew

you should coat it or no doubt, vinegar or not, the corrosion will come back. but do this easy. buy some Krylon crystal clear spray can lacquer and just spray a very light coat on the bare parts of the board. There problem solved. putting solder on the traces is a complete and total time suck, hard to do completely, and looks terrible when done.

If you coat the traces neatly, clean up flux, and then seal with color matching nail polish the repair looks almost factory and the corrosion will never come back. Bare copper with clear over top sticks out like a sore thumb. I still think solder on top of bare copper is the most ideal way to fix corrosion permanantly. It takes time and practice to do it properly and neatly. I should take some pics when i get home of bally mpus i have done this too.

Here's a couple of pretty good matches for the solder mask (I prefer to mask and spray, but these could also be brushed):

Testors 1601 Transparent Candy Emerald Green
Pebeo Vitrio 160 transparent glass paint -- Mint 37 is a touch darker than the Testors and if you need darker yet try the Tea Green 15

I like Barakandl's technique with the desoldering gun. If you don't have one you could also use solder wick to remove any excess solder and get a perfect looking trace.

Who cares if the sealant is green or not? Just seal it like clay said and be done with it.

If he ever goes to sell the machine potential buyers may care. They may view it as a hack repair.

you're just sealing it so the corrosion doesn't come back. when i see green paint on traces, i think to myself, "what is under that mess?" also any additional work is difficult because of the crap on the traces. And i can't see what's going on if there's a trace break. And trying to re-solder on that green mess doesn't really work.

Soldering the traces looks bad too. again i see it and think how much time and effort and solder (which frankly isn't cheap anymore) was wasted in that effort.

because of this, again, a far better, quicker, more transparent, and easily repairable solution is a quick and thin coating of Krylon Crystal clear on the effected areas. Personally i use the satin finish type, but gloss works too. You can see any problems in the future. And the lacquer burns off instantly with the touch of a soldering iron. So the board is repairable in the future.

I bead blast the corrosion on the boards i work on, and use just a thin coat of satin Krylon Crystal clear to seal it. It's the most effective, cheapest, quickest, and best solution to a corrosion problem. It also looks professional, and not like i'm trying to hide a corrosion mess, and make the board something it's not.

When selling circuit boards, appearance is everything to a lot of buyers.

If you can't lay down an even layer of solder and match some solder mask (neither of which is even mildly difficult) then you shouldn't be charging people to repair their boards. If you're a hobbyist and want to use clear paint I really don't care, but I think it's appropriate for the professionals to point out the best way to do things.

solder mask was there when boards are new. when they get wave soldered at the factory, solder mask prevents solder from sticking to certain parts of the board. that's it's only function. after the board is wave solder, the green solder mask serves no purpose.

re-applying solder mask is goofy at best. i can see it a mile away. and it makes repairing the board in the future much more difficult, and in some cases, impossible. if that's what anyone thinks is a good idea, then i guess go for it. but i don't see the advantage to it. it's another nail in the coffin for that particular board.

If you're not bead blasting corrosion, at least in my eye, you're not really removing the corrosion. piling new green coating on the board just masks the mess. in every case where i've seen some green coating applied, it was because the corrosion on the board was not properly addresses. When i see green re-applied, i know what's under it - improper corrosion repair and problems with this board in the future. The green just makes it harder to see and difficult to do any future repair. And in every case i've seen it, the green was applied because corrosion wasn't properly removed, and someone is trying to hide that fact.

if you do good corrosion repair, there's no need or reason to hide the work. also making the board repairable in the future where things can be seen and repaired is the best approach. re-applying green is not the best approach - it's hiding work and making the board difficult to repair in the future. i don't think coating solder on traces is a good approach either, but i can live with that, if it doesn't make a mess.

There's a lot of different ways to do repairs. I personally just don't like the re-coating the green because of the issues it causes down the road (difficulty in future repair, hiding work, etc.) That doesn't mean it's necessarily wrong. I just don't think it's the "best practice." (I know of a very good repair guy in my area that won't touch a board that has been re-green coated, and for good reason. it causes a lot more work for the repair, making it cheaper to just buy a new board.)

Nailpolish wipes away instantly with acetone if you need to rework something. I ensure the board is 100% corrosion free, working, scrubbed clean front and back, flux removed, etc, before putting the seal coat on.

I don't blame your guy for not working on boards other people have messed with. Reworking bad repairs is sometimes the most tedious of jobs. I would rather work on a corroded virgin board than one someone had a tough time soldering / replacing ic sockets on.

Seriously. Not good to argue with a ninja.

If I don't have green conformal coating repair bottle with me, I just use clear nail polish.

Either cleans off with acetone (unless you want to pay 10x and get the actual Chemtek brand of remover, that smells like acetone) .

The clear **may** have the advantage that you can keep an eye on any underlying corrosion should it start again.

I try to keep it off the pads themselves so you can still tone them out.

I have also used clear nail polish to glue down a loose foil trace to back to the board after any soldering is done.

There's always different ways to do things. but there is a difference here. it seems using the green approach is for cosmetic reasons first. what i recommend, using a thin clear spray, has practical reasons (with no cosmetic implications.) that's the difference.

here's what i do...
1. remove all effected components from the corroded board. this especially includes sockets. most of the "small stuff" i usually leave, because they will get cleaned in the next stuff. i will often neutralize the corrosion with yellow mustard too.

2. bead blast the board. this removes all the corrosion effectively and quickly. Because the sockets are gone, the corrosion under the sockets is also treated.

3. spray with a light coat of satin Krylon Crystal clear. note i do this *before* i put anything back on the board.

4. put the removed components and sockets back. anything that came apart during the bead blasting that i didn't remove before also gets replaced (usually not much though, bead blasting is fairly gentle.)

the point of this is the coating goes on the whole effected section of the board. if you don't seal the board, air will start the corrosion again over time. it doesn't matter how well you remove the corrosion, it will happen.

not putting clear under the sockets is a mistake. because that's where it will come back if you don't address this. again the clear is functional, not cosmetic. i'm looking for a long term solution to the corrosion problem.

and as Vid said, masking things in green just clouds the whole thing. you can't see what is going on. this is why i don't think it's a best practice.

below is a picture of a board i bead blasted and sprayed a light coat of clear on today. This board didn't have severe corrosion, but it was damn near over the entire board. hence it got lightly bead blasted nearly everywhere.

board.jpg

How much would you charge to take on my High Speed CPU? It works fine, no problems but the acid damage is on about 8 chips and I don't know what the traces look like. It has no hacks that I can see.

personally i don't do that type of repairs. my gig is in-home service. there are plenty of people doing mail-in board repairs. i like Jerry Clause ( [email protected] ) for mail-in board repair. but others are quite good too.

corrosion started can not be stopped only delayed by sealing from air contact after cleaning

the quick way to protect the sanded traces to copper color is to use a solution of the solder resin called "colofonium" , solution can be made with industrial alcohol and applied with a pencil brush
to radio shack are also some pencils with different resin solution consistency
http://www.radioshack.com/product/index.jsp?productId=12582876

This way will seal traces for air contact and help any future solder

I would PM barakandl (his info is in the posts above). He does good work.

Unless I'm missing something, the problem with using a resin would be that once heat has been applied or someone cleans the board you've lost the protective coating.

This is a do it yourself cheap and quick method to your own board to which you will not apply a power heat blower or apply any cleaner, if apply 2 or 3 coats of this solution with one hour dry in between it will last OK in normal use conditions in a pinball backbox and if you want to solder or make measurements on the traces after some time it is more easy than after a krylon clearcoat or any other lacquer (paint )

after using Krylon crystal clear (or standard lacquer) you can solder the board without an pre-clean or work. this of course assumes a thin coating (which is all that is needed.) the idea is to lock air out, and pretty much anything will do that. i juse Krylon because i already have it around for other pinball needs.

Here is one i did yesterday. It was pretty baddly corroded, but concentrated mostly on the bottom of the board.

I forgot to take the initial picture. Board was green and fuzzy all over the bottom section of the PCB. The 5101 socket was obviously wasted and many parts where broken already.

Here is the board after wirebrushing off the initial crap, i clipped out then desoldered out most the parts i plan on replacing. I also stripped every IC socket and header pin.
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Here is the board after removing all signs off corrosion with sanding. I have nice shiny copper that will happily take on solder. I also lost a few traces from corrosion. They where just corroded all the way through and there was no copper left.
20140215_181746-957.jpg20140215_181803-781.jpg

Now I stitched compromised through holes and repaired busted traces. I tinned all the copper with my desoldering gun which makes a barrier against corrosion. If you do not do this, the board will corrode over again in a few years. Then i repopulated the board, cleaned off the flux, and tested for proper operation.
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I went light on the green here =P. Final seal. Ready for long time of trouble free use.

20140216_133647-489.jpg20140216_133654-251.jpg20140216_133703-332.jpg

WOW! That's a lot of work. You really know what your doing.

I'm impressed anytime someone can take a board that is highly corroded and make it work! That said, here's how i do it, which is slightly different. Not the best video but you'll get the point. Sorry it's so long (10 minutes.) This should have been a 5 minute video!

Love it! I am jealous of your test rig. I have a game that is always opened up just for testing bally/stern stuff.

would be awesome to have that testing rig for every era of game out there. Would be so handy. I should make one for zaccaria like that.

i have a test rig for nearly everything. only ones i don't have is whitestar (not really needed frankly), zac (again how often do i need that??), and bally 6803. I have a Gameplan test rig and i'm sorry i invested the time in that one! but that's how the gameplan repair guide got written... but that's another story for another day.

I don't think it was to long, I was glued to every word you said. So...I have a High Speed board that has acid damage but it works fine but it's probably a ticking time bomb. Would you be willing to take it on? PM me if your interested.