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