Bill,

I’m glad you enjoyed reading about the project. You are correct, the EPA concerns are one reason to use vacuum infusion, which limits worker exposure to the resin and solvents. In addition, the vacuum exhaust could be scrubbed to minimize the environmental impact to others.

Another reason to use vacuum infusion is to offer better control over the resin content. With vacuum bagged wet lay-up, it is important to control the resin in some fashion, either by careful roller/squeegee work, or the use of wet-out machines that turn the work into a “wet-preg” exercise. With vacuum infusion, the resin content is controlled by the physics of the process in a way that is more consistent, reliable, and less work than what can be achieved with vacuum bagged wet lay-ups.

Wet lay-up is less complicated, but I disagree that it’s easier, and it most definitely is more work because someone has to apply and squeegee a bunch of resin. I think one of Charlie’s cautions is that with wet lay-up, the wet-out and squeegee work is time consuming and not very forgiving. That is a valid concern. If one were to then vacuum bag a wet lay-up, there is additional time involved with getting the bag and other stuff on while the resin is kicking off, adding time to an already long and potentially hectic process. When I’m done laying a single layer of glass on a stripper, I’m ready for a break, not another layer (right Charlie?).

But if one is going to vacuum bag a wet lay-up, then the difference in the materials required for resin infusion is trivial but the timeline changes completely. With resin infusion, a single person can take as long as they like to drape the fibers, apply release cloth and flow media, seal the bag, and check for leaks. I spread this out over many evenings after work, and could walk away or be interrupted at any time without consequence. So, in many respects resin infusion simplifies the process and creates a much more forgiving timeline in addition to offering better resin control compared to wet lay-ups.

Sam

: It's pretty cool that you did it, and I'm envious that you tried.

: The normal reason though for vacuum infusion is to get around the EPA's rules
: for commercial molding. For a one off it would be an awful lot easier to
: do a wet layup and if you really wanted it light then vacuum bag it. Can
: even use high temperature epoxies and bake it without spending a fortune
: to really get it light . Still you need to build two boats to get one, and
: have a bunch of extra equipment to buy. Not exactly cost effective.

: For serial production though it can make sense. But that's just me

: Bill H.