Zippy Plastic Welding

Jan 12, 2024

Plastic welding isn’t a new idea. But a recent video from [The Maker] shows an interesting twist. Given a broken piece of plastic, he secures it together with tape, machines out a channel around the cracks, and then melts zip ties into the channels. Honestly, although he mentions plastic welding and soldering, we aren’t sure this isn’t just simple gluing, but it did give us some ideas. Watch the video below and you’ll probably get the same ideas.

The ingenuity here isn’t necessarily using hot plastic to glue together two pieces — that’s just a hot glue gun, after all. Rather, it occurred to us that the key here was machining out the places where significant amounts of the hot plastic could bond the two pieces together. He cut the channels with a rotary tool, buffed them, and used a hot knife to give them some internal texture. But with a 3D printer, you could build these channels into parts that were made to interlock.

Think about it. Two pieces you print that have some type of tab arrangement to interlock. But their surfaces provide a built-in “glue canal,” sort of like he builds on the video. At the end, you could use some of the same filament in a 3D printing pen or even rigged in a hot glue gun like the zip ties and make a perfect connection.

We haven’t tried this, but it seems like a good idea. We’ve certainly glued parts together before and covered many methods for alignment, too. If you try it, do share the results!