> Many motors rely on air flow through the vacuum for cooling the motor. If
> this is the case, place a shut off valve in the vacuum line and turn the
> motor off as necessary.
> 2 stage shop vacuums do not have this problems.
> 5-10 pounds vacuum is enough for many epoxies. Too much vacuum will cause
> the epoxy to outgass.
Don't think a regular vacuum cleaner gets anywhere near that vacuum. Probably 1-3 psi is more like it for them. Heck, even the legendary Oric has to use a large funnel to pick up his bowling ball. For cooling air flow, and pressure regulation, I think the normal air bleed built into most vacuums would suffice. Don't know how well they'd take to being run that long though. By and large, vacuum cleaners are run for short bursts only. Shop vac shouldn't have this problem though. A shop vac (or house), duct tape, and a roll of that cheap plastic drop cloth and one could perhaps build up a decent vacuum bag.
Good point about the outgassing. Especially of the wood. One might be able to use this in reverse. As in vacuum bag the wooden boat for a while, then take it out and apply the epoxy for better suck in. I have no idea of the time factors for wood to retain vacuum and have no idea if this idea would work at all. But it's interesting to think about.