I'm about 6/10 on successful re-wicks -- still trying to pin down the variable. Most of my problems, as highlighted above, seem to stem from thin bits of cotton getting trapped on the sides of the post when clamping the mesh down. I would start there. The alternative to being very careful about getting cotton trapped there is to overfill that area with cotton...which I haven't tried yet.
The other variable is how tight to make the mesh/cotton. If I overclamp, I seem to choke the wicking, while underclamping burns the crap out of the cotton...even on temp control, for me.
As Gallant has pointed out...really take your time to fluff out the cotton. And don't let your cotton sit much higher than the height of the posts. Those are "given" measures of success.
Normally, I would be close to giving up on a tank at that success rate...but when this tank works, there's not much else out there that can compare to it (for me). Very thick vapor with what I can only describe as a "more pure" flavor.
Anxious for someone like Vic or VapnFagan to do a build video.