Hi all! First post, so thanks for such an inspiring community and I hope this post ends up in the right place! 
Now, I'm new to leather work, having only made a few axe sheaths and odd little bits. I tried the other day to wet-form a small zippo case using 5oz VegTan leather. So I dropped my leather in a pan of fairly hot water, and noticed straight away it shrunk considerably. Having moulded it and pressing it against my Zippo, I left it overnight and the following day to dry. I came home and started fiddling with it, and noticed it was really brittle. 
So my questions are: is leather supposed to shrink so dramatically when submerged? And why did my leather become brittle and snap when I tried to punch holes in it? 
Many thanks in advance, 
Louie