Most important thing I’ve learned is that any leakage is a no-no. Where I first thought an ultra sound leak detector is just a waste of money, I had to reconsider this opinion. So, I purchased one from Airtech to be able to find that very tiny bastard, virtually unnoticeable in this stage, but spoiling the fun during the infusion. On the other hand, some extra attention with the sealant tape will pay back. There is no rush to do this fast while there is no curing laminate as with the hand-lay-up vacuum bagging.
Pleats in the bag are unavoidable and even necessary to keep the bag from bridging. A spacious bag is no problem, but too tight is. So, these pleats are double sealed with the tacky tape. Making them is not difficult but requires some patient and handiness. Ones understood every sealed bridge will be tight, but if there are leaks in the bag this is the first place to start looking. It is obvious that for a bag like this only dedicated vacuum materials are suitable, a strong vacuum film and a special sealant tape. Materials like the pvc or pe sheets one can buy at the local home-store and window seals or duck tape are a waste of money and energy. I tried the first bag with pvc, and it just did not work.
I made a video clip of the infusion of the second hull half. On special request from one of the e-group members on the Multihull Boatbuilders List I’ve added a John Williams sound track to catch the accompanying ambiance 😉
By the way, you can find this video and more also in the Controlled Vacuum Infusion page.