Warning, a lot of stupid random thoughts ahead.
So, I don't want to buy a vacuum pump to vac-bag my parts. I only make a wing or two a year. And my house is small so I don't have anywhere to keep all this stuff.
I have been using a hand pump, a car brake-bleed vacuum pump. It's a pain to use, but it works.
Other ideas:
1: wet up part with carbon and epoxy, then wrap peel ply and paper towels. Place this into a waterproof bag, then sink into a deep bucket of warm water - say, 1m deep.
2: wet up part with carbon and epoxy, then wrap peel ply and paper towels. Place this into a plastic bag, put in pit, fill pit with sand.
For home made parts, I'd assume that either method would be OK and give reasonable results.