CA Glue to resolve threading issue

[Tony.]

Sorry if this has been asked before. I have trawled previous post but have not been able to find an answer.

For some reason, the cap thread on a recent kitless pen is lose for the corresponding cut barrel thread. It does not screw on, rather it just slips on.

I have CA glued the Cap, tapped it, CA glued and retapped it and it seems to have worked out fine.

My question is; will a CA glue thread hold up over time?

I haven't got enough cap thickness to add in an inset so this is the only option I can conceive short of rebuilding a new cap.

 

[alpha1]

Long term I am not convinced it will work. But I might be wrong.

 

[Phil Dart]

I'm with Dave - I'm not convinced it will survive I'm afraid. CA is fairly brittle and is not very resistant to shock.

Here's a suggestion for you though. You've said you don't have the thickness to add an insert, so I'm guessing its the female on the cap you're seeking to amend. Drill it out to the diameter of the major - make sure you get rid of all existing evidence of the thread. Turn a plug and glue it in with 2-part epoxy and start the process again. You'll end up with the helix entirely of the plug material, but as its epoxied in (and stabilised along the way with CA), you should have a sound result.

You can apply the same method to the male on the barrel too if necessary. Just turn away the old thread and epoxy on a ring in order to start the process again. In both cases, the glued on piece will lend integrity to the structure, so you don't have to be too concerned with thin walls.

 

[Tony.]

Thanks Phil - good idea, I’d not considered that.