My first attempt at leatherwork is not going well.  I wanted to make a valet tray, using thicker leather as I want to burnish the edges.  The snaps that I purchased don't have much holding power and don't even come close to holding the corners together.  I have had them clamped for several weeks in hopes the leather would begin to take a set but it doesn't appear to be having any affect.  Do I need different snaps or is there something I can do to these snaps or the leather?  The leather is 9 - 10 oz.
 
	Thanks for any tips.