Kydex as a molding material

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#1

I’ve previously posted on carbon fiber composite longboard/skateboards I construct. I’ve experimented with various molds which are used to vacuum bag my CF and corecell constructs. These forms are either convex or concave and build camber in the board when vacuum bagged. The form or mold is merely a curved 12" x 50" epoxy surface coated buck (though this may not be the proper use of the word buck) I make by taking a large piece of acrylic plastic window from Home Depot, bending it and securing in a wood frame. I then lay up an epoxy surface coat, fiber glass on the acrylic sheet and use stray pieces of corecell to reinforce.
It’s difficult to do and the results are variable.

I was thinking of using two large sheets of 0,080" kydex 12" x 48" and thermoforming the smooth side up over a curved surface, joining two together to make a two sided mold. (It would look like a symmetrical wing. I would place a pvc pipe down the center and reinforce with expandable polyurethane foam. This would allow me to rotate the mold around the pvc pipe and decrease edge pooling and permit two board simultaneous build. I could also use the central pvc pipe, if properly drilled thru, for later infusion, if I went that way.

Is this realistic? Is Kydex a reasonable surface to mold onto?

Thanks

#2

That seems like a reasoanble material… I think I’ve used it for flanging in the past. I go to the plastic supply places and they usually have a scrap pile which I raid. I’m pretty sure I’ve used it. It has the qualities of PVC which usually is a decent material to release from.

The most important thing when using these sorts of materials is maintaining your shape. I often use aluminum sheet metal to form molds for quick prototyping of parts and it works well so long as I have a good back up structure to keep things in place.

I’d try it out first before investing to much into a setup. But if you know you want to make multiples of the same part, you might want to go with maybe a more durable mold. You can make a plastic faced plaster mold fairly easily and cheaply that would be more durable than a sheet of plastic.

#3

I have used kydex quite a bit for molds. It works pretty good. It does scratch pretty easily, so not really a great long term mold.