Just to add, the model shop will also sell the loctitite. Two types, one that permanently locks the thread, if you unbolt it you'll need to reapply the loctite. The other type stays soft, and allows you to loosen, then retighten. Not quite as strong, but more durable. I'd go for the latter type, as you ought to take the bolts out at least once a year to make sure they don't 'weld' into the shoe anyway.
