I need some help from the experts here in the Workshop forum. I am needing to glue some clear plastic pieces together....plastic-to-plastic. In the past I usually use epoxy for this type of project, however this time it may not be the best choice. I need an adhesive that is very strong, waterproof, and that will remain clear. Every epoxy I have tried always discolors. It usually gets darker as it ages too. I am hoping to find something that goes on clear and stays clear forever....or at least for 50 years or so!

Any suggestions?

Thanks so much!

I'm afraid you may be out of luck.

Virtually any glue, and also any plastic you can buy commercially for home use.. or even mostly for pro-sumer use, will yellow over time.

If the plastic is acrylic, there is a two part acrylic glue you can try. the shelf life on it is short, and it smells so bad I couldn't use it inside, but it may be a good bet. If it's not acrylic, I don't know of anything.

Can you run a test with good ol Super Glue?
It seems like a no brainer but I have found only a few plastics super glue will NOT work on.
When I was in the sign industry, the typically used a high bred super glue for all acrylic signs.
It was called "Thin" which was a nick name as it was a very thin, easy flow super glue, used to adhere the acrylic cut out letters on to a background sheet of acrylic.
This is always tough if you do not have a test piece as any glue you add may make things worse.

Thanks guys. I have used the acrylic solvent in the past but I was hoping for something thicker, that would fill the gaps a little because it has to hold water.

Chance, I can make a test piece and try the super glue. Like the acrylic solvent it will be too thin for this project, but you guys have given me an idea: If I can just get it glued together good and strong, I can then seal it with a clear caulk, or sealant.

I'm not sure if the super glue or the acrylic solvent will be strongest. A good, plastic epoxy would be fantastic if it would remain clear. A little yellowing might be ok, but I have used some epoxy resins that turn really dark, almost brown. As Michael said, the plastic itself might yellow some over time so a slight yellowing of the glue might be acceptable.

Thanks guys!

P.V.C. Pipe weld/sealant dries clear on the outside of a joint, though I'm not sure what it looks like
where the surfaces are face to face. Get it from a plumbers merchant. It's about £4.00 a tub over here.

There is a product called "Water Clear" silicone sealant that is used in glass showers. Once you get it glued, this would be good for sealing, and it never seems to yellow. It's expensive, but worth it, if clear is what you're shooting for.

http://www.amazon.com/C-R-LAURENCE-Water......01C7X3CC

Thanks guys! I have looked at so many products...I'm about to overload! LOL

I actually found a product where I bought the lexan that sounds promising. Clinton, it is a clear, waterproof silicon sealant, so it is probably similar to the Water Clear. I am about ready to do a test, so I'm keeping my fingers crossed!

Thanks so much for everyone's help!

Trying to glue plastics is the biggest mystery of the universe. The problem is, there are so many different types of plastic. Trying to get an accurate ID on something is often very hard to do, and even then, some plastics simply will not take any kind of adhesive.

I recently tried to glue a small metal part to a plastic skull using a really high-tech adhesive. It appeared that it might work, but then, POP, the piece came right off. However, the blob of glue was perfectly contoured to the part of the skull where it was originally, and hard as a rock, so I drilled a hole through it and the skull and ran a pop rivet through them. Voila! Perfect fit!

Be careful, because "Clear" comes in a milky clear for about $5.00 a tube, or water clear for about $25 a tube. There is a big difference!

Michael, I have felt that same kind of plastic gluing pain in the past.

Clinton, yes, you are correct. The type I got is somewhat milky, but it is plenty clear enough. The crystal-cut plastic hides it completely. I bought spare pieces of everything, so if this ever breaks or this adhesive doesn't hold up well I will have to try again. This stuff seems to stick fairly well, but at the same time my test pieces were glued at a 90 degree angle and I was able to snap them loose easily enough. My real piece will not be subjected to very much pressure, and it has much more glued surface. It also curves so it should have enough strength.

I just finished my project this morning and I like how it turned out.

I really appreciate all of the help! I couldn't have done it without you guys!!!