I’ve been experimenting with a couple of workflows and materials and wanted to give/get info out to see whose working on the same. I originally went to the lab to vacuum bag (VB) a walker pre-cut and get to know the materials and sequencing. After looking at the costs involved in VB, I have been thinking of alternatives and cost saving measures. Here my thoughts.
• Reusing nlyon vacuum bags - this may seem impossible since the sealant tape is strong an adhesive but after putting the VB in the large freezer for a couple of minutes (~30), the sealant tape released the bag. So now I’m wondering how this can work for the backyard glasser. Maybe ice cubes or dry ice to run along the tape to get it to release and then roll it back up on its core with the wax paper backing or keep on one side of V-bag and use barrier to save for next use.
• Also, slice/cut Sealant tape in half, thirds or quarters? In a non oven vacuum, small strips of tape seemed to work fine.
• Peel Plys seemed like it could go a couple of uses if release film is used.
• 4 mil or 6 mil polyethlyne plastic sheeting at home depot or lowes as an alternative to VB’s nylon high temp bags (rated at 400F)
• paper towels as replacement for breather material (previously stated on Swaylocks)
(VB supplies at http://www.airtech.com/ )
• A vacuumless vacuum bag ( I dont know what to call it so pls dont call me on this misnomer): As a test, I took some 3M thermoplastic window film (6" X6" square), the kind that tapes to the inside of windows and with double sided tape seals out cold drafts inthe winter, I did a small wet out of two small patches of 4 oz S- glass and taped the 3M Film down, oversizing the test patch so the tape was sticking to EPS #2 foam and not touching any wet resin (RR version). I took a hair dryer and heated the plastic to get it to shrink and pull tight. I worked a few small bubbles out to the side and added another layer of tape. When I removed after the cure, it looked like a smooth finish, just like the VB effect without the Peel Ply texture. Also, the film acted just like a release film, no sticking to epoxy resin. I am going to test this out on a small test board (~2 ft long and 10" wide) to see how the plastic conforms to curves and bends. Pics to come. The price comes down to about $2.90 a yard at 60" wide ($19.95 for window kit) and comes with double sided tape that could be used in a regular VB set up.
Also, here are some pics of the layout I did for VB testing. Sorry, no web page created to easily show these off yet. http://www.goldenzah.com/Surfboards/surfboardpics/
More to come.