New undertray/flat bottom idea
 

So my friend has this carbon fiber roll that he has to keep in the fridge. Basically, when you take it out you have a few minutes to cut it to size, wrap it, lay it, whatever you want, and then heat it with a heat gun to harden it completely. I was trying to find out where he got it from, but he's really busy and I don't live next door anymore so it's hard to keep in touch.

Anyways, I was thinking of making flat undertrays by fastening it in between the frame rails of a car with large rivets or bolts or something, then I realized that I could probably just use heavy duty fabric.

http://www.gardenista.com/files/img/...th-natural.png

Why couldn't I use some fire proof canvas or fiberglass cloth and make a whole undertray? By stretching the fabric tight and bolting or by making wedges to pinch it along the edges it should be strong enough to not flap in the wind.

I know isn't 100% air tight, but it's also not 100% "heat tight" so it may be a good compromise between ventilating transmissions and exhausts and not letting air get all turbulent underneath the vehicle.

Another Idea I had was to make the thing, then coat it in resin with a brush, a few layers to firm it up. then I would be able to cut out or louver it in areas that need venting. it would also retain it's shape when taken off of the vehicle that way

Thoughts?

I'm digging the resin-coated idea! You just lit up a big light bulb over my head. :thumbup:

What if you added a thin layer of foam and a layer of resin resistant material between the underside of the car and the composite weave? That would provide a wee bit of spacing so the tray wouldn't stick during the impregnation process or rub after installation (with rubber grommets or washers for spacing).

Once this is laid up, it might be used to make a mold to produce additional pieces.

It sounds like the material that your friend has in the fridge is "prepreg" … it's quite pricey and needs to be heat cured.

Just an FYI. "Fireproof" doesn't usually mean "won't burn", most fireproof items simply won't sustain a flame. Meaning if you take a heat source or flame to them they will burn or melt but as soon as you remove it they self extinguish.

harbor freight has fiberglass welding blankets.
4 ft. x 6 ft. for 22.00, 6 ft. x 8 ft. for 28.00, 8 ft. x 8 ft. for 36.00. I have the 6 X 8 and it looks like it would work for a belly pan.
8 ft. x 8 ft. Fiberglass Welding Blanket

If you saturate any sort of cloth or felt with something that goes on liquid, then gets hard, you have created FRP (fiber reinforced plastic). The liquid that gets hard can be polyester resin (the cheap stinky stuff), epoxy resin (better, more expensive), varnish, shellac, etc. The fabric can be cotton, fiberglass, Kevlar, carbon fiber, or paper. Google Taylor paper glass for an example.

The Recumbent Blog » Blog Archive » Taylor-Paper-Glass
Future of Materials in Formula 1. - Forum - F1technical.net

Whatever you try, it will sag without a mold. Gravity is inexorable.

Consider fiberglass reinforced plastic panels or PolyMetal.

So... you're saying that you could buy a couple of bed sheets and saturate them with a resin and make your own underbody tray THAT WAY?!

You're giving me all sorts of ideas!

(obviously it would need to be structurally supported...)

I have been looking for a larger sheet size of something like FiberFix to repair large rust holes in my black truck (in Black color).

Really large sheets might be used as part of an under-body tray assembly.

FiberFix | Now you can fix anything!
http://www.fiberfix.com/wp-content/u...ht-300x511.png

Let me know what you guys find.

Some of the products listed so far sound heavy, prone to moisture absorption and problematic (fire/installation issues - gravity).

The FiberFix is crazy expensive for what you get in my opinion.

I tried a roll of FiberFix. The black tape with a picture of a repaired shovel handle on the package.

My experience was that it would barely stick to itself, let alone anything else. YMMV.