What is the best glue to repair pinball ramps and plastics?

I hope this information contributes to the final answer to this question.

The product is called: 
Weld-on - SciGrip Smarter Adhesive Solutions
3 Very Fast Set - Clear, water thin solvent cement
(used with the applicator shown)

It is one of the solvent cements that the plexiglass industry uses.
It works so well that it is considered welding…not gluing.

First of all I have no idea what ALL “plastic” pinball ramps are made of but, the few I have worked with seem to be made of polycarbonate. Also, I have no idea when pinball machines began using polycarbonate plastics, but it is unlikely that it was earlier than 1970, because it was only in 1970 that they perfected making “glass-clear” polycarbonate.

Most pinsiders have heard of the Lexan washers that protect play field plastics from breaking. Lexan is a brand name for polycarbonate. Lexan (polycarbonate plastic) takes a whack much better than plexiglass (acrylic); so it is a reasonable assumption that most modern games are using polycarbonate in all ball impact areas.

This stuff has a VERY fast working time of 1 minute, fixture time of 7 minutes, 80% strength in 24hours (and about as strong as it is going to get at 48 hours)

No need to give your plastic “bite” by roughing it up. In fact, you want smooth surfaces. Capillary action will suck it in place.

CONS: Weld-on solvent cement is easier to use on plexiglass (acetate) because it drys clear on plexiglass (acetate) if you make a mistake and accidentally drip some of it on the surface of your material (don’t attempt to wipe up a mistake, it will evaporate)

But unfortunately, if you make a mistake on polycarbonate it will not dry clear, it will cloud your clear material. So when working with it LESS IS MORE.

The secret of joining any two pieces of plastic is having the applicator (and figuring out how to use it without dripping) and letting the capillary action do its job, and most of all practice makes perfect.

Capillary Action:
This can have its cons as well. You will be tempted to tape two broken halves of plastic together before joining them. That is a mistake, because capillary action can suck the liquid up under the tape which can ugly-up the visible surface of your play field plastic. Don’t get me wrong, you can use tape to hold two pieces of plastic together, but just make sure the tape does not touch the crack you are attempting to join; use a toothpick to raise it from the surface slightly. so basically if you use tape to hold your two pieces together keep the tape off the surface of the plastic so the solvent will not travel under it as well.

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Strength experiment:
I put my Addams Family play field in a service position and glued two 1/16 inch thick strips of polycarbonate plastic to part of the plastic near the swamp under the play field. I let it adhere for 48hours. On one strip I used Weld-on solvent cement, the other strip i used epoxy (seen in position below the other, was a total fail)

I then tried to break the Weld-on joint by stressing it with weight. After putting nearly 19 pounds of weight the weld would not fail.

The plastic was even being pulled in a direction where weight should have sort of peeled it apart, but still the joint would not fail.

BTW the epoxy piece literally pop off when I touched it (you can see that one below the weld-on solvent one)

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I threw a mini clamp on the polycarbonate piece and wired a bag on the end and started adding weight
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It would bend, but the joint would not break.
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I actually became more worried I would break the plastic gutter on the pinball machine.
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I put over 18 pounds of steel junk weight on it but could not break the joint
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Ultimately I had to cut off the test piece, the joined hunk is part of my pinball forever
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I later used Weld-on solvent cement to join two pieces of polycarbonate (and let set for 48 hours). I found that the bond was stronger than the original piece of polycarbonate. The weld shown no signs of failure after 58 lbs.

It is tough to see what I did here so I will explain.

The joined area was probably 3/8 x 3/8 of an inch.
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I attached then suspended a bucket from the pieces and added every bit of steel I could I could find.
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My wired together testing rig broke before welded joint did.

58 pounds of steel... no stress to the joined area.
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After the rig broke this is what the piece looked like...as you can see the joint is unchanged.
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Here was my first experience using the Weld-on solvent cement to repair and reenforce my Addams Family ramp.

I had a break on my ramp were it is held in place by the screw, so I wanted to graft a piece of polycarbonate in there.
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So carved out a bit break in my ramp with my Dremel.

Then put a piece of 1/16th polycarbonate on the bottom, I clamped it primarily because when I clamped it down to my grafted piece the two parts joined a bit more flat and that is essential for the capillary action to suck the stuff in and get you a good even adhesion.

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I only let it set up for about a half hour then I unclamped.
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In the mean time I had carved another piece of 1/16 inch polycarbonate and placed it in the broke area.
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then added solvent and held it in place until it set-up

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and finally another piece

This was my end result. It is FAR stronger than the original and I am confident it will never fail again.

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Again, this was my first experiment. I am sure it would look better with practice.
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I ended up adding another shot of the solvent after I was done, which as you can see clouded it a bit. I did not really care, I was more interested in strength than beauty, and you really can not see it anyway unless you are looking for it. It is now solid as a rock.

The secret is definitely learning to use the applicator to cut down the dripping.
Here is a great video to learn how to use the applicator

I will have to try #4. But the clouding with #3 is really only an issue if you mess up and drip it on a open surface, if you do it properly with the applicator and let the capillary action suck it in, your joint will clear. If you are new to the solvent watch the video above and learn how to use the applicator before trying it.

I am sure this stuff would really kick some butt just joining some snapped plastics (like vid mentioned above). My experience has been less-is-best with this stuff...meaning avoid adding "just a little more"; which for the life of me is a lesson I will never learn.

Also, regarding drips I experienced a worse problem with clouding on the polycarbonate material than regular acrylic.

Okay so here is the #3
http://www.amazon.com/gp/product/B00466V8F0/ref=pd_lpo_sbs_dp_ss_1

Here is the #4
http://www.amazon.com/gp/product/B00466V8F0/ref=pd_lpo_sbs_dp_ss_1

I have never used the #4 and the dude in the video recommends the #3 on polycarbonates here:
https://www.youtube.com/embed/3KzZDi-aXD4?autoplay=1&rel=0

He is pretty specific about #3 usage with polycarbonate (which is what pin ramps and plastics (at least on the modern pins) are made of, he does not specify anything about #4 but it sounds like it is maybe for polycarbonates as well...with just a slower set time. rplante above mentioned using #4, but I have no experience with it. Again, I am not exactly an expert with it.

The stuff is cheap enough per can, I would guess someone here will buy both and compare them.

You need to buy an applicator, or two (which you can see on amazon in the "customers who bought this also bought this" area.

You could have just gotten the staple hot with a candle and it would have melted in

Basically the applicator is dull syringe needle. You guys have to remember that the applicator is made to help some plastic fabricator design some big ass plexiglass box or whatever, the applicator might hold an ounce.

But for a Pinhead joining couple of broken pieces of play field plastic back together... drop might be enough for a 1 inch crack.

This worked really great for me... Do you know how you removed a screw from a ramp and you can see bunch of little hair line stress cracks just waiting grow?
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The solvent will not react to metal, to fix all the hair line cracks around your screw holes (obviously this is AFTER you have removed the ramp) place your screw back in a bit, give the the screw a tiny bit of solvent right where it is touching the plastic.

The capillary action will suck the solvent in the cracks. After a few seconds or so unscrew the screw and let it dry.

NO more stress cracks.

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Exactly right ^

You are creating a new piece of plastic at the joint. The stuff is not glue it is a solvent

sol·vent definition: "able to dissolve other substances."

So while you will go to your grave, as will I, calling it a glue. It ain't!
Used properly it dissolves the plastic where is applied and erased the crack from existence.

Talking to the guys that sell plastic at my local store, specific solvents vary from plastic to plastic. This Weld-on product specifies: Styrene, Butyrate, polycarbonate with an overall labeling of “ACRYLICS”.

So it would really be great to find that the older ramps were butyrate. Some testing needs to be done, I do not have access to broken play field plastic or I would test it myself. Anyone that has some broken play field / ramp plastic should get some of this solvent and repair a break and stress the hell out of it a few tests. (<-- Vid I am looking at you

It would really be great be able to removed glue/ epoxy from the playfield restoration equation, in lieu of a cheaper much more effective solution.

I am more curious what the old playfield plastics were made of

No idea man... buy it and experiment around. This whole topic is uncharted territory as far as I am concerned. Right now we know that the #3, that I started the thread with, works at least on Butyrate so it says on the label (which the pinball oracle vid has notes is the material in the play field plastics of not very recent machines) I used #3 to attach a polycarbonate piece to the plastic on the underside of Addams Family (see above) and I could not get it to fail in my stress test. So in that case if the Addams family gutter (or whatever the hell that plastic gutter thing under the play field is called) was made of PETG, then we know that #3 attached polycarbonate to PETG; if that is the case it should attach PETG to PETG... you would think.

Again I do not know what type of plastic my Addams family ramp plastic is, it just seem to behave like polycarbonate, so I made the guess that was what it was.

But one thing is for certain regular plexiglass breaks like a mother. but polycarbonate bends (Lexan is a polycarbonate) and #3 works perfectly with both of those. So the #3 has at pretty wide range of use between those two very different types of plastics.

Edit:
I just bought some Weld-on 16 myself upon the local plastic store recommendation. It has a consistency that is much thicker. And it is specifically rated for polycarbonates as well.

The #4 is like water. the #16 is in a tube more like glue. I have not had the chance yet to try the 16 but I am eager to.

The capillary action should draw it in. I would love to hear how it works.

No I have not gotten chance to try the 16 yet, if your local plastic shop has the 16 at $12, I would give it a try. I think the big difference is set speed, the 4 works in a few second, which personally I prefer.

I just bought a $100 WWF Royal Rumble, so now i have some plastic to do some more testing.

The machine isn't working.... but it might only be a fuse.

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