Last time we talked about a video that purported to do plastic welding, we mentioned that the process wasn’t really plastic welding as we understood it. Judging by the comments, many people agreed, but it was still an interesting technique. Now [Inventor 101] has a video about plastic repair that also talks about welding, although — again, we aren’t sure all of the techniques qualify.
That’s not to say there aren’t some clever ideas, though. There are several variations on a theme, but the basic idea is to use a bolt or something similar in a soldering iron, metal reinforcement from things like wires and staples, and donor plastic from a zip tie. While we don’t think the nylon in a typical zip tie is the best way to repair anything other than nylon, if you were repairing something 3D printed, you could easily swap out the tie for filament of the same material, which — we think — would bond better.
Some solutions come from no more than looking at two dissimilar things while in the right mindset, and realizing they can be mashed together. In this case I had recently segmented a large, hollow, 3D model into smaller 3D-printer-sized pieces and printed them all out, but found myself with a problem. I now had a large number of curved, thin-walled pieces that needed to be connected flush with one another. These were essentially butt joints on all sides — the weakest kind of joint — offering very little surface for gluing. On top of it all, the curved surfaces meant clamping was impractical, and any movement of the pieces while gluing would result in other pieces not lining up.
