Glue for Delrin/acetal?

[homebrewed]

If you can poke a aluminum cylinder-part into a hole (like for grub screw fixation), can you NPT-thread it?
If so, a bit of abrasive grit and any-old-glue will lubricate the threaded coupling, tighten until the
grit bites into both the aluminum and Delrin. When the glue dries, so the grit can't shift, it'll
hold (one hopes). Tapered pipe threads guarantee a snug fit without careful machining, I've found. (#blush)

The two pieces are components in a roller arrangement. Sort of like a miniature roller blind for a window. An aluminum tube fits into a bored-out pocket in the derlin (it's part of an axle assembly), and the overlap is less than .25", so difficult to NPT thread them. Your suggestion on using abrasive grit + adhesive is clever! I'll have to remember that one.

I tried some PL construction adhesive. I have an already-opened tube of the stuff, left over from a barn rehab project so what the heck. It seems to be holding alright. Fortunately, this particular application doesn't apply much force to the joint so I think it will be OK.

If the joint does let go, I'll pin them together and be done with it.

 

[RJSakowski]

Delrin is not bonded by solvent welding. In particular, Delrin is rated as having fair resistance to a 48 hr. exposure to MEK. Hexafluoroisopropanol is a solvent listed for solvent welding Delrin or acetal. Not likely to find it at Hardware Hank's.

I have used thermal welding of Delrin. The fumes are nasty so you want to do it in a well ventilated area.