Hi all building gurus
I'm about to start the molds for my foils and I was thinking about doing the mold out of polyester resin as I've heard that Epoxy has a hard time bonding to it, and this would be an added bonus for releasing the foils. Has anyone done anything like this and what are the pros & cons of this method? As I'm doing parallel leading and trailing edge shapes to start with I use a method where you drag a template of the foil shape through some thickened resin which leaves the impression in the surface once it goes off. I've built foils this way before for my moth and it works OK, as long as you only want parallel edges. I've contacted some CNC people but haven't had any luck with anyone who will do foil molds for me so I'm looking at my options right now.
The template dragging method sounds okay. Used to be a common method using plaster in pattern making.
Don't rely on the poor bond between poly and epoxy as a form of mold release. It will still bond well enough to ruin your mold and/or part. I use Partall #2 wax and spray on a good coat of PVA film. I'm sure you guys have something similar. That works well on rough molds.
A western red cedar or what you call oregon core is a good way to go for a one-off board.