Well the other day I needed to repair my board. I got a big plastic sandwich bag and used a needle to punch lots of holes on one side. Then I folded some kitchen towel and placed inside the bag and used masking tape to seal the whole thing.
I hooked up to the vacuum punp and watched the resin bleed into the towel. When I pulled everything apart the job was tight and perfect!!!
Does make you wonder why spend money on specialist materials!! I'm thinking of making a spiked roller just so I can make my own preforated plastic sheet!!