driver's seat mold preperation

[Will M]

Hey guys,

I've been been working on the mold for the driver's seat and I have finalized the geometry and am working on preparing the surface.The mold is made from insulation foam and plaster and I plan on using a duratech product to finish it. What I'm looking for is a product to protect the foam and plaster from the duratech because our previous methods (2 gallons of plaster, layer of fiber glass, then bondo, then duratech)took forever to smooth. I've read that laytex paint can be used for that, thoughts from somebody with experience using it for molds?

Thanks,
William

tags:
driver seat , mold preparation , mold surface , carbon fiber

[Will M]

Hey guys,

I've been been working on the mold for the driver's seat and I have finalized the geometry and am working on preparing the surface.The mold is made from insulation foam and plaster and I plan on using a duratech product to finish it. What I'm looking for is a product to protect the foam and plaster from the duratech because our previous methods (2 gallons of plaster, layer of fiber glass, then bondo, then duratech)took forever to smooth. I've read that laytex paint can be used for that, thoughts from somebody with experience using it for molds?

Thanks,
William

tags:
driver seat , mold preparation , mold surface , carbon fiber

[Rotary Sprocket]

Latex paint will work for sealing the foam, however i don't know how the duratech and latex paint will react with each other. This might be something to look into before you do it because it might have undesired results. If you want the surface of your mold to be smooth, I don't think using latex paint by itself will work. Unfortunately for hand made room temperature molds your process (tons of filler and sanding) is the only way you're going to get a nice mold. But hey that's what makes mold making so enjoyable.

[JoshH]

I've used epoxy resin for this sort of thing. After the epoxy is surfaced you should wash it with water and scotch-bright pads in order to remove the amine blush; this gives the Duratec a better surface to adhere to. You should check with the Duratec guys about which epoxies they recommend though, as their tech sheets say adheres to MOST epoxies. They have a good tech line that can help you.

Josh

[Pico]

Bondo: Fibreglass body filler compound

We used this on our moulds for many years even up to today. It's a filler and catalyst that you mix and apply it to add a hard surface which you can sand to a good shape then we spray a few coats of duratech and sand smooth. The body filler+catalyst has an exothermic curing, so the foam will shrink a little. It's pretty much the best thing we've found for foam based moulds.

[Will M]

^^^ I did a quick google search and found some sailboat sites indicating that Duratech should work with acrylic latex paint.

^^ Epoxy would be a great option, but if I can get away with something cheaper...

^ My last two seat molds (and body work molds too) used lots of bondo and plaster filler, and one of my major goals has been to eliminate bondo and limit the filler. This final mold should only use one 4'X8' sheet of foam and one quart of plaster filler.

William