Creeping evidence

Heres the starboard side arm where it joins (or is supposed to join) the top frame on BH1. SOB decided to go for a walk after I thought it was going to set in place. How to avoid this?

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And this is my new paperweight/epoxy trophy that I just cracked out a yogurt container. At least I got my container back! There are 2 ziploc bags and probably 20 bucks worth of epoxy in there.