This may be a dumb question but where would i find the ‘‘micro balloons’’ to make the sealent mix to seal eps foam amd can you use anytype of epoxy hardner?
Wardo…
One source is Aircraft Spruce & Speciality Co. at www.aircraftspruce.com.
They also carry cab-o-sil, milled glass fibers, flocked cotton, as well as the micro balloons. A 1 lb bag cost about $ 6.50 + shipping. (Part # 01-14600) Look in the on-line catalog under Composites, and then the Thickening Agents.
Ken
so i would just mix that cab-o-sil with the hardner and spread allover blanks the sand and glass? How much to i mix with it the s-foam site said 1/1 but is that weight or volume?
Wardo…
As you are only trying to seal the foam, I think I would mix the filler to the consistency of mayonnaise so it can be squegeed over the board. A light coating is all you want to do, not build structure. I’m not sure what the exact ratio is, I usually go by the consistency of the material. Once sealed, you have several options, you can let it cure then sand the finish then glass as normal, or to get a better chemical bond, would be to let it tac, then lay your glass, and complete your lay-up. This is a bit more difficult, but will create a better chemical bond.
Ken
cab-o-sil and micro balloons are very different… use micro balloons… greg strongly suggests the spackle over the epoxy/micro balloons…
jjp is correct in suggesting the spackle for sealing the blank. Some folks like the micro balloons or other fillers, but they will add additional weight to the board. As for the epoxy, I would suggest Resin Research 2000. Other epoxies have dark amber amines used as a curing agent, and will make the board look a bit yellow, where the RR epoxy is water clear, and has the UV additives. Remember to use the additive F when glassing and doing your hot coat!
Ken
i know this is getting to be the same questions over and over but i thought the spackle was micro balloons/hardner mix?
Sorry if I confused the issue… if you listen to enough people around here you’re bound to get confused.
I was referring to the SFoam website and their specific recommendations for their foam. They also say to wipe with denatured alcohol and sand before lamination.
Greg Loehr has recommended the spackling stuff.
“I’ll third that … Dap Fast&Final” (9/30/05)
Jim Phillips has apparently used epoxy resin directly over the sanded blank and picked up enough foam dust to create a slurry of sorts.
“I don’t use any micro balloons added to my epoxy, I don’t blow off the blank before I start, just keep it free of hand prints. It takes about 3 ounces of Resin Research epoxy to seal the bead foam and the styro dust mixes into an excellent putty that chemically bonds to the foam.(I feel that using spackle, fills, but maynot get that chemical bond, the board I snapped at Sunset had the glass locked onto it) A sanding and it’s ready, but I put on a second sealer that lays as smooth as linoleum and give that another light sanding.” (9/1/04)
Several opinions and as many ways to skin a cat?
For the micro balloon slurry, you will want to mix micro balloons, epoxy resin and hardener.