Aeromodding Materials?

[jime57]

I want to make some screwon aeromods to my Echo. I already have grillblock, underbelly, rear skirts, and moon wheel covers. I want to clean up the front wheel arches with some screw on shaped clocks behing the tire and along the top. I also want to create some additional streamlining blocks to install in front of tires.

I think I read somewhere that spray foam insulation was compatible with fiberglass resin. That would be an ideal combination, if in fact it works. I know from experience that styrofoam isn't compatible with resin, infact melts when subjected to resin. Any other materials worthy of consideration?

Jim E.

[aerohead]

Originally Posted by jimepting

I want to make some screwon aeromods to my Echo. I already have grillblock, underbelly, rear skirts, and moon wheel covers. I want to clean up the front wheel arches with some screw on shaped clocks behing the tire and along the top. I also want to create some additional streamlining blocks to install in front of tires.

I think I read somewhere that spray foam insulation was compatible with fiberglass resin. That would be an ideal combination, if in fact it works. I know from experience that styrofoam isn't compatible with resin, infact melts when subjected to resin. Any other materials worthy of consideration?

Jim E.

Open-cell styrofoam can be coated with white glue ( Elmer's ),and then it will tolerate polyester resin for composite layups.Epoxy resin will not attack it.

[jime57]

Open cell? Are you talking about the "normal" type styrofoam like used in coffee cups or available in sheets and blocks, or something else?

[myplasticegg]

Open cell is the majority of foam that you can buy in a store. Using elmer's is a great solution to the problem, so is laytex paint. Whatever you have laying around the house should work. Just make sure you do a trial run on a test piece first.

[jime57]

Got it, and thanks a lot for the help.

[Bicycle Bob]

Dave Cloud covers his foam with masking tape. it might help to flash off a hot, unwaxed gelcoat first. I'm not sure about compatibility, but you might get a head start on your shapes by using plumbing pipe insulation jackets. You can also buy urethane foam, which is impervious to polyester. Epoxy resin is another option, but if you want Bondo to stick to it, use System Three SB-112. That is a great barrier coat to stop rust, too. Unlike paint, it keeps even water vapour out.

[davidgrey50]

It's important to distinguish expanded polystyrene (the disposable coffee cup and cooler stuff), and extruded polystyrene, which is what is usually found in pink sheets at Home Depot. You DON"T want the expanded as it is nigh impossible to get anything resembling a smooth finish without huge amounts of filling since it comes apart in thoes nasty little white chunks which stick electrostatically to everything. You DO want the extruded, which is sandable.