i am drag racing some and need to lighten the back seat and engine hatch. They are currently made out of wolmanized plywood and covered in normal upholstery. Back seat weighs 100 lbs and hatch weighs 75 lbs. What can i make the seats out of to save a lot of weight?

Not sure what they look like and how much strength you need. You could use NIDA Core it is VERY light and strong when used properly.

I agree, a foam core will be just as stiff and way light, the tough part will removal of the plywood.

where do u get the foam and nida core material

I get it from a place called Composites 1

Not sure if they will deliver to you from their location. They are not retail but they will sell to about any company so maybe if you or your boss can run it through your company. If not give me a call and maybe I can help you out.

http://www.compositesone.com/locations.htm

There is a place local to me called fiberglass coatings inc. http://www.fgci.com/ that sells it I believe.

There is also a core material called core-cel which you can also get through composites 1 as Audoifn recomended. It is great if your lookin to get more strength then the nida core will give you. But yes the nida core will work great if you don't need alot of strength

I used this HD foam product for stringer replacement ...Coosa ...

http://www.coosacomposites.com/

If it's wood, what about using a hole saw, maybe 1" or 2" diameter and drilling holes equally spaced. Kind of like perforated wood. Of course this would have to be done in areas that can't be seen.
Dave

Anybody ever make an aluminum engine hatch? Mine must weigh 200lbs and I'm considering an alum. frame with upolstery over it...