u will need:

1. Rawhide 
2. Polycarbonate
3. Water  based polyurethane varnish - like TDS Hauthane HD-2209
4. press or clamps 
5. Heavy grit sand paper  60-80 grit
6. MDF


Step 1: Build a press or get some clamps

Water based varnish works well to bond rawhide to polycarbonate. most epoxy is too brittle- and contact cement is too weak- and will both fail a heat/freeze test.

because the water based varnish proved to be the best glue for this application a manual press or clamping pressure had to be used instead of vacume bagging because the rawhide and varnish need to be exposed to air to dry.  MDF is the perfect material to protect the rawhide and disperse clamping pressure because it can let air pass.

picture shows a large press constructed of Unistrut from Lord and Sons in San Jose 

Looks cool, but why glue leather to polycarbonate?
its rawhide-(un-processed leather), rawhide is translucent, polycarbonate is clear, and heat insulative, rawhide is sensitive to heat, both rawhide and polycarbonate will be ontop of L.E.D. array - and polycarbonate is electrically non-conductive -ish.. the purpose was combination aesthetic and problem solve--
Interesting process, but what is the purpose or application?
it is an artistic application, see &quot; http://www.instructables.com/id/LED-Light-box/ &quot; for the end result - <br> <br>-
the freeze/heat test was to test the integrity of the bond as it went through varying climates during shipping and storage. Rawhide responds to humidity and temperature changes by shrinking and expanding with a surprising amount of force. it would pull itself off of an epoxy bond to polycarbonate within 30 min of direct sunlight exposure, or 10 min in a 180F deg oven. 3M has a heat resistant flexible epoxy but it is around $1K a gallon, a gallon of varnish is 20$. The application required glass like clarity and temperature resistance, see my instructable &quot;L.E.D. light box&quot; to see what the rawhide/polycarbonate composite was used for.
You mentioned freeze/thaw test...I'm curious about how this was used. Thanks <br>