Plastic Weld solvents

I'd use CA ( Super Glue ).

Regards, Rick

Not much will work with the polyethelene type toy plastic. Best would probably be 2 part epoxy. Painting it is a problem too.

glueing LEGO together!!!! that nothing short of blasfimy!

My Lego blasphemy might not be so bad. I sawed off some of those balls from the legs & arms from Throwbots, threaded them with a 10-32 tap & die, and used them for ball hip joints on the pelvis of a mech I'm trying to kitbash. I should buy some acrylic balls for this kind of job. I had ideas for using other lego parts as glue-on bolts or moving rods with the end stuff glued onto them, but that sort of stuff is being made out of Plastruct now.

I thought Legos were made from ABS

the bricks might be abs. If they are, Ambroid should work. Those aren't the parts I've tried Ambroid on yet. I was working with those rods & balls that are like hard vinyl or something resembling teflon.

I haven't bought any legos in a long time, so I guess I don't know exactly what parts you're talking about.

Usually when manufacturers say vinyl, they mean polyvinyl chloride (PVC), so I would think that you could get an appropriate glue at the hardware store.

If the plastic is high-density polyethylene, then I don't think there's any way to solvent bond it. I had to buy some acrylic from a distributor once; while we were there, I asked about some HDPE that he had on display, but he said we couldn't glue it together; it would have to be mechanically fastened with nuts and bolts. That, plus it was more expensive, made us stay with acrylic.

I doubt the pieces are Teflon because teflon is very expensive and overall has poor mechanical properties... it doesn't wear well.

If you can't get it to work using solvent or glue only, you might wan't to try drilling holes in the things you're trying to glue and then use some epoxy. The holes should be wider at the bottom than at the top, preventing pull-out of the epoxy.

There's absolutely no way to bond HDPE, even cyanoacrylics fail here. Only thing you can do is heat weld it. Use a piece of metal heated up to about 100 deg C or a bit more, press two parts of PE to be welded for a short while against this hot piece (be careful not to burn yourself) and then instantly press them together and hold firmly until it cools down. It requires some practice and doesn't work well for glueing PE and another type of plastic.
To bond ABS (Lego type plastic) sand down the surfaces with high-grit sandpaper and glue using cyanoacrylics.

BTW, ABS stands for Acrylonitrile-Butadiene-Styrene copolymer Chemistry is great

EDIT Ups I didn't notice the main topic of this thread. There's absolutely no way to bond ABS and this flexible plastic with a glue. Use screws, nails etc. Even if you managed to glue these together, the bond would be very unstable.