What will epoxy NOT stick to?

Right, That'll work as long as the central threads don't actually fill up. I suppose I could drill out the epoxy, but I'd risk buggering up the brass threads.

If a greased screw can keep most of the epoxy out of the center, then a tap can clean the rest.

"Archimedes' Lever" "Phil Allison"

Sheesh, dude. Think about the application!

..... Phil

You have a lot of interesting answers! I run into this thing with RC airplanes. Usually mine involves T-Nuts instead of inserts. To keep the goo off of the threads I tape the ends closed.

HOWEVER, if you are dealing with a blind hole the hydraulic forces will overpower any seal you might try. You could cut some relief slots in the side walls to relieve the hydraulic pressure but it would be iffy. Glueing a wood plug (better than a dowel!) in the hole which has been cleaned up to provide a snug fit and redrilling is probably a better solution. If you have access to a metal lathe you could also make an oversize insert like the commercial one. This is the route I would prefer on a gun stock.

John Ferrell W8CCW

OK. Drill out. back fill with epoxy, placing plug just undersize from threaded insert normally used into epoxy for later removal. Epoxy dries. Plug is removed. Before epoxy hard cures, insert the insert. maybe with a little fresh epoxy as a 'wetting agent'. allow cure.

V I O L A. Dat's about as good as it gets. The deeper you drill it out and make the epoxy backfill, the stronger it will be due to integrating with more of the dowel's length. Add fiberglass fibers to make the epoxy matrix stronger still (usually).

The most professional-looking repair would be to backfill the hole with something like "plastic wood", and re-drill/re-thread it. Or, you could tap the existing hole one size bigger and use a Helicoil.

Otherwise, I'd try Vaseline on the screw.

Good Luck! Rich

It finally clicked in, there was a discussion here recently about trying to use adhesives of any kind on polyethylene, and pretty much nothing worked. Will that do?

As long as you don't leave a screw in the hole of the insert, it probably doesn't matter too much, you can very quickly clean out the thread with a tap, as the epoxy is softer than the brass, especially if it is warm.

Chris

John Fields wrote in news: snipped-for-privacy@4ax.com:

the -machine screw- he plans to thread into his brass insert does not have internal threads,the insert does.

Somebody will surely spend half a week trying to do it.

I have seen a tube of Teflon pipe dope that could be used to displace epoxy in an internal thread scenario.

ed

ed

Not really, You use a long version of the machine screw you intend to use and wrap the tape on it. You then thread that into the insert. You then epoxy the combination into the wood. When the epoxy is hard, you thread the machine screw out and then pull the tape out. It is a trick that I have used.

John Fields wrote in news: snipped-for-privacy@4ax.com:

but NOT the threads he was planning on wrapping tape *around*.....Sheesh!

a machine screw with internal threads?

I meant wrap the screw and screw it into the insert before gluing the insert in,

it seems like the wrong part.

you gan get wood screws with a machine thread at the head end. put a thread joiner on one of them, drill a recess (for the joiner) and pilot hole (for the screw) into the dowel and screw it in.

(use a lock nut - standard metalworking practice)

having the thread away from the end of the dowel will greatly increase the strength,

using varnish or polyurethane wood glue to lubricate the screw seems like a good idea too,

PS. it's not a pool cue is it?