----- Original Message -----From: DocSent: Saturday, June 15, 2002 5:34 PMSubject: Re: [PSUBS-MAILIST] Mini Nautilus MinisubJust a quickie, then back to the boat.
I've found epoxy will stick to polyester and vinylester, but, polyester and vinylester will not bond well to epoxy. Go figure!As to the styrene foams, if you're just building a quick plug, cover the foam with a thin layer of FixAll plaster, then paint, wax
and lay up with polyester or whatever.Later,
Doc
Right on Doc, I should have mentioned that, while epoxy sticks well to most surfaces, almost nothing sticks to fresh epoxy; not even masking tape. It dries with an almost "oily" feeling to it. What one can do is (1) wipe the fully cured epoxy surface down with Acetone on a paper towel to get rid of the "slickness" and let that dry; then (2) sand the surface well with extra coarse sandpaper to give it a "tooth" the resin can "fill in" and bond to, and then apply polyester resin and glass cloth. Works fine.Yep, I've heard about the plaster coat method, too. And I've heard one can even use regular house paint on top of that. Sounds economical for large projects.For the general info of anyone thinking about this kind of project: when making a foam plug out of multiple layers of that 1-inch thick extruded styrene foam insulation available at hardware stores, it might become necessary to glue the stuff together. There are glues especially designed for use with styrofoam, but one "all purpose" cement that I've found to work well is Elmer's PROBOND polyurethane glue. Doesn't contain any volatile spirits that "eat" foam; and will adhere to most anything. When dry, it can be sanded during the forming process, too; but be sure you're working in a well-ventilated area and wearing a dust mask. You don't want to breathe this stuff.Of course, when in doubt about any of this, one should take a small amount of the material(s) being used and test them to see how they behave.VBR,Pat