Thread lock did not stop the extender slipping.
It seems slightly better than before, but still coming loose.
What are your welding skills like @Kels_316 ?
@wileyfuller is it steel?
@Kels_316 it is. Pretty thin walled though.
@wileyfuller hmm, brazing might be a better option? What needs to be joined?
@Kels_316 Brazing would probably work too.
How to extend a steerer tube - Framebuilding 101 with Paul Brodie

YouTube
@wileyfuller oof yeah that's a major operation. You could probably find a local fabrication shop that could do it?
@Kels_316 Yeah... At which point its probably cheaper to just buy new forks.
@wileyfuller the challenge would be to not introduce a bend when you're welding it, the sleeve inside would help that but it would be tricky.
@wileyfuller TIG would be the best way, but I don't have the gear, just MIG.
@Kels_316 I've been wanting to do some welding, but not sure this is the best thing for me to start with.
I can easily picture myself with a pile of expensive welding gear and a ruined fork.
@wileyfuller yeah I don't know what the frame would be made of, in terms of steel either. Could be very easy to fuck it right up. Might be worth taking it to a fabricator though, it might be cheaper than you think.
@Kels_316 I'll call around and see.
Pretty sure the forks are mild steel. But not sure about the steerer tube. Could be chromoly, but probs not.
@wileyfuller @Kels_316 Time for the *real* thread lock, aka. Araldite
@neoluddite @Kels_316 I was considering filling the whole tube with epoxy. I might try a couple of other things first, but it's definitely an option...
@wileyfuller @neoluddite looking at that design again I would maybe try wrapping the cone nut with something so it pushes out harder on the fingers, it has to be that part that's causing the problem
@Kels_316 @neoluddite Also, it only seems to be the centre part of each finger which is making contact with the inside of the tube, and even then mostly at the top and bottom. Increasing the contact area would probably help.
I'm going to try wrapping some sandpaper around the expander to see if the (presumably) increased friction helps.