[redshift]

Some plastics don't weld, which is another reason to not waste money on a kit that may not have the type you need.

And a good test for this is to take your soldering iron (which most people have already) and see how it reacts. If the plastic tends to burn instead of melt, then it's a 'dry' plastic and must be bonded with glue.

Nylons would be hit or miss because there are so many species lol but most styrenes fuse like the break never happened, if done right.

ABS is weldable.

Polycarbonate (lexan) is out, forget welding it.

Do the burn test, with an iron or small torch (if using a torch then do it quick to avoid carbonizing the plastic) and if it looks like it wants to drip like wax, you are in business.

Practice on some scrap material, and remember when doing a repair if you have enough material to spare you can beef up the repair joint just by adding more material. Or you can embed little pieces of metal, carbon etc to do a 'composite' joint and make it even stronger.