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?
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.