Mick,

Only the inside of the hull was vacuum bagged. First, the release cloth, bleeder cloth and poly bag were fitted to the empty hull. Bubble gum tape was run around the outside, an inch or so down from the shear. I bought the release and bleeder from Fibre Glast (on the web), and used poly sheeting from the hardware store for the bag. With the vacuum stuff rolled up out of the way, the biaxial cloth was laid in the hull and trimmed up, then wet out. Again we used a more resin than called for by calculation, but the end result was OK due to the bleeder cloth. Two vacuum ports (suction cups from Ace) were spaced evenly in the hull area, and we pulled 8-15 inches of Hg - first 8in to get going and then 15 until green cure. I borrowed a nice rotary vacuum pump for the job so we had way more capacity than needed and used a bleeder valve placed between the pump and the vacuum gage. The gage was positioned at the T connector to the two ports. We put an inverted test patch on top of the bleeder cloth up near the bow, so we could see how things were going.

The process worked fine but I would not do it again. It was just an experiment with a different technique and to get some experience with bagging. Aside from the additional cost, the extra effort could not be justified except for the experience.

We noticed no problems with out gassing. A seal coat was applied first and allowed to semi-cure. No problems there either.

The Gougeon brothers have a useful booklet on vacuum bagging, and the Fibre Glast web page has some good things also.

I hope this helped.

Sam

: Hi Sam

: I guess you're one of the few w/ experience vacbagging strippers. So would
: you answer some questions?

: 1/ the obvious 1st one is how did you do it? Did you remove the hull, and do
: it off the forms, or did you remove it, put down poly on the forms, put it
: back and seal to that? How much vaccum? Do you think it worked? Both i/s
: and out? etc

: 2/ And outgassing. It seems to me that if outgassing is a problem under
: normal circumstances, that w/ vacbagging, it must be a huge problem. Like
: low pressure all around the wood should cause dissolve gas to come pouring
: out? - was it a prob.?

: 3/ and sealer coats. If one put on a sealer coat, is it not possible that it
: could pop off under vaccum? Any comments?

: thanks for any answers

: -mick