Hi,
does anyone has any experience with using foamboard as flange material and is it safe to use with polyester resin/gelcoat or will the styrene eat up the foam inside? Also can modeling clay (the oily kind that never dries) be used to fill the gaps or will the heat the resin distort or melt it?
Thanks!
Expanded and extruded polystyrene (insulation board) will get melting by polyester and vinyl ester resin.
I’ve never used clay with PE and VE but I have used it quite a bit with epoxy.
The clay will not melt with PE resin.
http://www.sculpt.com/catalog_98/clay/Van_Aken/Van_Aken_Oil.htm
I use oil-based clay with PE gelcoat and resin and have no issues.
So you are making molds out of the oil-based clay and covering it wil PE gelcoat to make the plug? and the Clay doesnt distort?
I wouldn’t rely on this method for a mold. Unless its super tiny and more of a test in design outcome.
Maybe better to overlay the clay design with PVA, then a few glass layers that will be sanded and polished for a proper plug perhaps. Mold from that.
Molds 101…MUST be non-moving surfaces.
Unless you use casting methods to make the mold rather than layup methods.
Modelling clay is used a lot in casting applications. With all kind of materials, EP, UP, VE, PU, Gypsum.
The stuff does not seem to get attacked by anything. However, turpentine dissolves it.
For flanges try and source some other cheap sheet. Aluminium for instance.