DIY Fiberglass carb bonnet?

Franken-Truck · #1 (**permalink**) 07-08-2008, 07:15 PM

I can make it no sweat, but will fiberglass and West System epoxy resin hold up to under hood temps? I know it's hot under there, but is it that hot?

BTW, this is for a custom intake/air filter setup for my carb'd 460.

Thanks!

EDIT: Just what exactly can be made from fiber glass under the hood? Can I make a set of Valve Covers? Intake?

triton_2002 · #2 (**permalink**) 07-09-2008, 09:41 PM

Is there a spec sheet for the fiberglass kit you plan to use? That should give you the max temps for the material. Is the air filter gonna be a ram air type where it will stick out of the hood? That should be ok, with air flow to cool it. I've heard of older corvettes having holes burned right thru the hood (fiberglass body). You put on a chrome air filter on and open up the hood at a car show and the sun shines off the chrome and acts like a magnifying glass. Like burning ants with a magnifiying glass.

Franken-Truck · #3 (**permalink**) 07-11-2008, 09:24 PM

This would be a bonnet to take the stock AIR tubes and then connect to a homemade "Cold Air" intake.

And West System has a Heat Deflection Temp of 123F and max temp of 139F

Not enough or should I look for different resins?

triton_2002 · #4 (**permalink**) 07-11-2008, 10:04 PM

Thermostat operating temp is around 180F +, so what do you think?

Franken-Truck · #5 (**permalink**) 07-11-2008, 10:30 PM

true, but does that reflect the under hood air temp?

1972-34ton · #6 (**permalink**) 07-12-2008, 01:10 PM

A ways back, I found some pourable urethane in black that was intended for under-hood use. It was a two- part mixture. Came in quarts and pints.

My thought was to make something out of blue builders foam, and then brush the stuff on in a few coats. Then, eat the foam away with gasoline (this works on styrofoam anyway).

Can't find the link, but I think it was McMaster-Carr catalog.

Luck to you,

Kevin

triton_2002 · #7 (**permalink**) 07-12-2008, 02:23 PM

Quote:

Originally Posted by Franken-Truck

true, but does that reflect the under hood air temp?

When your moving and getting airflow, it might be ok, but stand still for a while with a big block under the hood and the heat builds up.

1972-34ton · #8 (**permalink**) 07-14-2008, 02:10 PM

I found temperatures exceeding 160 degrees under my hood while idling in traffic. This was measured with a temperature probe inside the air cleaner housing.

That might be too hot for fiberglass, though you might check the specifications on both Epoxy and Polyester resins.

A second advantage of the urethane idea is vibration absorption.

Franken-Truck · #9 (**permalink**) 08-06-2008, 10:53 PM

I figured I would share my findings with everyone. . .

They do make and sell hi-temp epoxies. They are expensive ($180~$300 per gallon) but have heat ranges from 300F - 1500F.

I did find one brand of resin that should work for this intended application. It's made by a company called Hexion and has a Heat Deflection Temperature of 130C (266F) which should be more than enough.

http://www.hexion.com/Products/Techn...t.aspx?id=3958

I want to contact their tech department first, but this is looking like the laminating resin I will go with when I do get around to it. Also, I did find a dealer on Ebay who sells the 1.3 gallon kit for under $80 which ain't half bad

never did find anything on that urethane stuff, though I didn't search THAT well. . .lol