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Comment by TeMPOraL | Hacker News Reader

> Plastic welding is a thing.

Good to know, I'll research it. In the past, I've attempted fixing plastic items with soldering iron and other sources of heat, up to and including open flame from a lighter - in every case, it resulted in burning and/or smoking and stinking plastic, and at no point the two parts became attached again. Not sure what I was doing wrong.

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Epoxy usually works for these situations, it can stink until it sets, don't get it on your hands but it's real cheap. Sub-$2 for the harbor freight tubes.

Even better, most of the plastic housings on things (think plasticky old dell desktop housings or lego bricks) are made of ABS. This stuff you can buy plastic weld that dissolves the outside of the pieces you want stuck back together. This stuff works well for that: https://www.amazon.com/Plastruct-Plastic-Weld-applicator-Bot...

That looks like a dichloromethane + MEK mix, but for ABS, acetone works very well and is cheaper and less toxic.

To clarify, plastic welding generally implies melting the plastic not with heat but with specific solvents. It's kind of "gluing" where there technically there is no glue (i.e. some substance that stays between your two parts) but rather a weld, where the edges of the parts get melted and stuck together as the "glue" (solvent) evaporates.

> melting the plastic not with heat but with specific solvents

Thank you, this is the core insight I was missing!

Some plastics melt at a certain temperature (thermoplastics like PETG/PLA) and others don't (thermosets like resin/epoxy). Its possible you just attempted to melt the type that just burns when you heat it.

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