Lexan adhesive

[RJD2]

What would be a good adhesive for Lexan (polycarbonate)? Thanks.

Ron

[drillman88]

I've used superglue with good results. The flexible stuff with rubber works well, the extra give lets it have a little movement.There is a special adhesive we use at work, I cant recall the name right now that is better. It "welds" the stuff together. I will try to get more info and find out if it is availible commercially.

[cabinetman]

What works best is a product called Weld-On. The #3 or #4 will work. The #4 is a faster set. Or, you can use Ethylene Di-Chloride. The cements work in a capillary action.
.

[pelligrini]

I've always used the thin viscosity model cement (usually Testors), but that was on Plexiglas.

[Tom Slick]

I don't have a specific product for you but in your search the key words will be cement or solvent weld. Although it may be referred to as adhesive, the products actually melt the materials together. That's why normal glue/adhesive doesn't work. Also, make sure what ever you use specifically states polycarbonate, its chemistry is different from similar materials.

[pelligrini]

My wife brought home a bunch of 1/2" polycarbonate display shelves she 'rescued' from a dumpster. The several tubes of superglue she used to put it back togeather didn't work very well. It looked terrible too.

I had to hide the pleased look on my face when the POS fell apart as she moved it. I did know better than to say 'I told you so'

[Larryl]

Lexan adhesive

I've used regular PVC cement(two part) with the purple primer and clear cement that I use on my sprinkler system. It has held better than the glues I tried.

[Stytooner]

For the thin stuff that is solvent, I use Weld-On #3. I use it in a syringe with Teflon needles. It does wick into the joints.
For sealer like around my dust ports, I use Weld-on #16. It comes in a tube much like plastic model cement.

These two products work on Acrylic, Polycarbonate and Pet G. Basically clear thermoplastics.

I used to get these at McMcaster Carr. A hobby store or plastic supply house will carry these or similar products under a different brand name.
Here are two other places I get supplies from.

http://www.tapplastics.com/

http://www.craftics.com/

[RJD2]

Thanks for the possible options. I only have to put a few pieces together, and purchasing an adhesive online in comparison to locally would be rather expensive considering shipping charges so an alternative would be more feasible.

Ron

[RJD2]

I purchased Weld-On 4 as well as a plastic bottle/needle based applicator, and would appreciate any tips on how to ultimately achieve the best results. My understanding is to lightly clamp the pieces together than apply a thin bead of cement along the joint. Since it is so thin, what is the best way to keep it from basically going all over the place? Could I mask off the the parts to be glued to avoid getting on places that are not supposed to be? Also, can the the cement immediately be wiped off with something like mineral spirits if it does get on parts that are not to be glued? Lexan is to expensive to mess up. Thank you.

Ron

[cabinetman]

I purchased Weld-On 4 as well as a plastic bottle/needle based applicator, and would appreciate any tips on how to ultimately achieve the best results. My understanding is to lightly clamp the pieces together than apply a thin bead of cement along the joint. Since it is so thin, what is the best way to keep it from basically going all over the place? Could I mask off the the parts to be glued to avoid getting on places that are not supposed to be? Also, can the the cement immediately be wiped off with something like mineral spirits if it does get on parts that are not to be glued? Lexan is to expensive to mess up. Thank you.

Ron

If you are cementing a 90 degree corner, lay one flat, and stand the other up, to make a butt joint. Make a corner bracket out of wood, like a 90 deg corner that you can clamp to both pieces to keep them in place. I use 3/4" stock and cut out an angle, and cut the outside corner off to allow for a glue line. If you need a sketch, I can post one Monday morning. Corner brackets similar to something like this, get mounted on the inside of the 90 deg at both ends, and I use spring clamps. The fit of the edge to be glued should be smooth with no gaps to the flat piece.

When cementing lay a small continuous bead so it "sits" where the two sections meet. You don't need very much, just enough to flow into the edge. Capillary action will draw the cement into the fitted parts. Be very careful not to spill any or dispense too much. You cannot wipe off the cement when wet, as it will make the surface cloudy. Once dry, solvents will not remove cured cement. I wouldn't tape off any areas, the cement is the consistency of water, and will flow under tape.

If you have enough material, try it with samples first.
.

[LCHIEN]

I purchased Weld-On 4 as well as a plastic bottle/needle based applicator, and would appreciate any tips on how to ultimately achieve the best results. My understanding is to lightly clamp the pieces together than apply a thin bead of cement along the joint. Since it is so thin, what is the best way to keep it from basically going all over the place? Could I mask off the the parts to be glued to avoid getting on places that are not supposed to be? Also, can the the cement immediately be wiped off with something like mineral spirits if it does get on parts that are not to be glued? Lexan is to expensive to mess up. Thank you.

Ron

Solvent cements are exactly that, they dissolve the plastics, let them run together then evaporate and leave a very strong, clean clear joint composed only of the original material which is important when joining clear materials for display cases and such. Getting solvent on the surface and then trying to wipe it off is an absolute disaster.

I'm clearly not an expert but i did know some experts and they use some rather nasty solvents - Not only that but it was a major art to join the two pieces and get the glue spread perfectly in between to get a clear joint with no excess on the outside and especially hard to not get bubbles trapped in the joint and to get the joint lined up before it set. Its not something you can expect to master in a short time.

[Tom Slick]

make sure the edges to be glued are perfectly square and straight. wet sand them to at least 400 grit, the edge should look almost perfectly clear before you weld the pieces together. When the pieces are put together the weld should become prefectly clear and have no bubbles, clamping harder can help push the bubbles out. If you can't get the bubbles out then your part is not sanded well enough or not square.
make several test/practice attempts to get the feel for the right amount of solvent to use, it will be more than you think.

[tseavoy]

I have found that PLASTIC SURGERY glue works well on most plastics, even nylon. Most hardware stores have it. I think it's made by Surehold.

Tom on Marrowstone

[LCHIEN]

I remember the solvent they used, it was methylene chloride.

using solvents to join plastics is called welding since the material flows together and becomes as one as in metal welding.

this wiki article lists ways to weld plastics - and specifically addresses using MC for welding polycarbonates (which generically what the material trademarked as Lexan is)
http://en.wikipedia.org/wiki/Plastic_welding