Stripped threads in plastic

[larrys]

I found that the threaded holes in my right side handlebar switch are stripped. I think that the PO was a gorilla, as everything that he had touched was waaay overtightened and/or stripped.
Since the plastic is ABS, I thought that I might renew the threads by adding material to the threaded holes. ABS pipe glue is basically ABS plastic dissolved in a solvent. So I used the end of a toothpick to drool in a bunch of glue into the threaded holes, but not filling them completely. I placed the switch piece with the threaded holes down, so excess glue could run out. After letting it set for a few hours, I ran in a 2.5MM tap to chase the threads. Put the switch back on the handlebar and much to my surprise it worked! YMMV.
Larry

[Dirk_S]

Very nice. I'll have to keep that product in mind.

Curious--instead of setting,then re-tapping, couldn't one just squirt/smear the glue into the hole, stick the screw in, and when the glue dries, the threads are made via mold casting?

[berniebee]

Great idea Larry!

[ridingron]

Better put some kind of grease on the threads.

[Don G]

You could also use Helicoils.  DonG

[normzone]

Curious--instead of setting,then re-tapping, couldn't one just squirt/smear the glue into the hole, stick the screw in, and when the glue dries, the threads are made via mold casting?

You could, but Murphy's Law indicates that you'd never get the screw out. Perhaps by using mold release, but you'd be gambling. Also the threads would be the inverse of the male screw used, when actually you'd want the female (slightly larger) thread in there.

But you knew all this already, and were just looking for someone to talk to. Me also ...

 

[lucky phil]

You could also use Helicoils.  DonG

Or in the best traditions of the backyard hacker stick a self tapper/PK/sheet metal screw in her, Heerk, poot, ding.

Phil