So I'm wanting to build a cold air box and I've never worked with fiberglass before. My question is: how many layers of cloth should I use to make each "wall" of the box? Will 3-4 layers suffice? Thanks.

 

two layers would be more than enough on any non exterior, non structural part.

 

I dunno about that.....

It depends on what material you are using as well. If you were to use heavy, boat weave, cloth, two layers would be enough.. However, if you were to use the finer, more flexible cross woven stuff, It could be four or five.

 

I'm not sure if it's the heavy duty cloth or not. on the package it says it's for house, automotive and boat use. if it helps any, the package looks like this: http://ace.imageg.net/graphics/produ...1134480reg.jpg

a question about layering: is it better to put two pieces of cloth together at the same time, and then apply the resin, or should you resin one at a time, and then put them together?

 

thats like the stuff from autozone and all. i would say around 6-8 layers with that stuff. for layering...just do one at a time and squeeze all the bubbles out everytime u lay it down. if u want to really see how thick the layers are in comparison to sometime, i can take an example picture of 8 layers if u want.

 

Common guys, he is making a cold air box.

Heck you could do it out of a peice of 22 awg sheet metal, and that would be considerably thinner than two sheets of fiberglass with gel coat on both sides.

Its not like it has to support anything.

 

no...it doesnt have to support weight but it does have to actually be able to stand some abuse without falling all over the place. 2 layers of that fiberglass is way to flimsy and could be easily ruined with the push of a finger. 6 is exactly what i would do....but thats just me. i was never considering gelcoats into this either cause theres no purpose for it in this application. its just what i would do....i dunno. but still like icemark said though...sheet metal is another option. itll prob be more practical and easy in your case because uve never worked with fiberglass before.

 

I don't think you realize exactly how thin that stuff is, Mark

Either way, after dealing with that same exact fiberglass, I'd get the mat that they sell right next to it do 1 layer of that (maybe 2, depending on how ambitious you feel), and put a layer of the stuff you have on both sides. that will give you a good structual base, and a nice smooth finish on both sides.

 

I'd recommend 4-6 layers for extra shielding.

I made one out of 4 layers and it was pretty thin(3 chopped strand and 1 woven).

Here's pics of the one I made.
http://edge_krusher.tripod.com/airbox.html
Beware it's got pop ups.

 

^ looks nice Digi7ech i got a question of my own i might be making a cold air box for my t2 does sheet metal work as good as fiberglass does it reflect heat around that area so more cold air go's in the intake or would you need to line the sheetmetal with aluminum or heat wrap

 

If I were to make another I woudl make it out of sheet metal/aluminum.

It's much easier to form and work with. I made over 20 adjustments to shapes on that thing to get it to fit right. total PITA.

Anything to help insulate the box from the engine bay will help.

My airbox did get hot to the touch so I'm not really sure of it's actual functionality. Although if you removed the washer resevoir and made ducting it would be great.

 

No, I have done a ton of fiberglass back in my old car stereo days.

For something like that I would just do two layers of woven glass, and probably 4 or 5 layers of gel coat/resin so that it could be sanded smooth. This would make a panel 3/16ths thick at the very least.

Radically thick enough.

But maybe a lot of you like to use a layer of glass with every coat instead. I suppose you could, but I would think it to be just a waste of money.

It sounds like if you may want this to last through a crash into a tree