View Single Post
Old 10-18-2009, 11:02 PM   #10 (permalink)
Master EcoModder
3-Wheeler's Avatar
Join Date: Dec 2008
Location: Southern WI
Posts: 824

AlienMobile - '00 Honda Insight
Team Honda
90 day: 80.05 mpg (US)
Thanks: 94
Thanked 550 Times in 189 Posts
Originally Posted by ChrstphrR View Post
Thanks for letting us see what you did over the summer! It's making the gears in my head turn for building a hybrid foam/fibreglass/metal tray in sections for my car.

I'm curious, though, about some of the unmentioned details of your build.

Did you glass over the top/inside surface of your tray?
Did you coat or prep the rest of your wood you mounted on the car to secure the tray?

I know the foam used would be impervious to water/slush/snow, but all the wood used, is another story entirely.
Hi Christopher,

Both the top and bottom side of the foam board is glassed over. This is known as typical 'composite construction'. The foam board by itself is not very strong, but very light. A layer of glass cloth impregnated with resin is itself is not very good in compression, but very good in tension.

When the two are added together however, now you have a very light, yet strong structure. Plywood is another composite structure of sorts. It utilizes various layers of grained wood to make a structure that is stronger than the base wood would be without the cross-grain structure.

All of the wood supports mounted to the car have been epoxied to keep the water out. The only weak area is were the wood screws hold the panels onto the car. Water can seep into those areas. Only time will tell how this holds up.

I do have a motorcycle fairing with 115,000 miles that is constructed in a similar manner and still looks good, but it is not mounted underneath a car body either. However, the fairing still gets rained on just like the car, since I typically ride it rain or shine when it's warmer, such as this summer when working on the smoothing panels.


Last edited by 3-Wheeler; 10-18-2009 at 11:11 PM..
  Reply With Quote