Well I tied a mock up vacuum bagging last night. Disaster! I knew that I'd
have to take it easy on the vacuum, but I didn't realize that my vacuum pump
wouldn't go low enough. And with my inept fumbling to control the dial, I
basically crushed my mock-up wing at 10" Hg. You basically need around 1" Hg
of vacuum to hold the skins with minimal bowing. My pump will go down to
around 5".

The only way this can work is if you had a bunch of narrow boards to transfer
the load to the ribs. I can see making kind of a wash board with a bunch of
narrow boards hinged together with fabric. But it will be an assembly nightmare
and I think you still need to clamp the TE to ensure it stays straight. Back to
John's KISS method! :-)

I'll post some pics of the disaster after I remove it from vacuum. I decided
to go ahead and complete the test. I'm going to leave it under vacuum for a
couple of days. The other burning question is if the silicon will dry while
under vacuum. I'm guessing yes, but I really don't know.