Brent, The material you are trying to negate with the powder I believe is a wax that is built into the resin that is necessary for proper polymerization of the resin. This is usually what is sanded off prior to applying another coat of resin/glass. If I remember correctly from my readings, you can obtain the resin without the wax but this resin should only be used for subsurface layers and additional layers have to be applied within 24 hours of each other. The last coat should include the wax material to limit air’s interaction with final hardening of the surface. Check formal references as I am rusty on this subject and haven’t looked at it for quite awhile. Infusion molding has a lot of benefits but is actually much more labor intensive then other methods especially when you look at all of the testing that has to go into developing the proper placement of the infusion/vacuum ports and calculating the flow of the resin. The labor is upfront in cutting and placing of materials but molds can be turned around much faster. There is a great article in the most recent issue Professional Boatbuilder that compares various methods of molding GRP hulls. An infused hull is generally lighter, stronger, and uses fewer materials with the large upfront costs spread out over a production run. R/Jay Resepectfully, Jay K. Jeffries Andros Is., Bahamas Save the whales, collect the whole set. From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Brent Hartwig
From: ShellyDalg@aol.com Hi Brent, I'm using "structural lay-up" resin for the first color coats with white pigment. The final color coat will be with "marine grade" resin because of it's anti water absorption properties. Regular gel coat is a common product for boats but the added resistance to water absorption in the marine grade is better when you consider the pressures these fairings are under while submerged. I've not tried the baby powder trick yet, and the PVA is generally a big pain in the ass. I'm using it as a coating on the plug molds and recently on the "wing" molds but it doesn't just "wash off" like the literature suggests. Pretty much have to sand it to get it gone. Frank D. |