Hi all, I'm making a carbon fiber part with a basic bend, no dramas there. All parts sorted. I've got a vacuum pump, basic oil based. It creates vacuum alright, but when I switch it off, air comes back into the bag and no more vacuum. It's a bit frustrating really. Should I just keep the pump running until the whole thing at least starts to cure? I've got the bag sealed ok, I think, and the connector, which I made myself, looks solid. When the pump is running, you can see that the pipe is flattened, sucking all air out. and when I switch the pump off, the pipe fills with air again. Very frustrating. Any advice would be great.