Fibreglass Box
Fibreglass Box
Hi, i am in the middle of fibreglassing my first box, its for 2 12's one inverted. How thick would you reccomend i build up the fibreglass? I was aiming for about 6-7mm is this enough?
Thanks
Rob
Thanks
Rob
At about 1/4" thick overall, I think that'll be enough.....
. I'm no expert but it seems asthough that is what I've seen many times..... I'll go out on a limb and say that's roughly 8-10 layers you'll be doing...... Check out fiberglassforum.cizom and do some reading.....

Those tender little burgers with them little, itty-bitty grilled onions that just explode in ya mouth like flavor crystals every time you bite into one.. just makes me want to burn this muthafuka down.... Come on, Pookie, let's burn this muthafuka down!!!
It also depends on the shape a bit Robbie.
Fiberglass is stronger on curved areas, so you can afford to go a bit thinner, but on flat areas it isn't quite as good so needs to be thicker, or have some bracing added.
I'll soon be starting my first FG box for ten years and have had some really good 'refresher' advice over on fibreglass forums
Fiberglass is stronger on curved areas, so you can afford to go a bit thinner, but on flat areas it isn't quite as good so needs to be thicker, or have some bracing added.
I'll soon be starting my first FG box for ten years and have had some really good 'refresher' advice over on fibreglass forums

- str3atwarrior
- Posts: 806
- Joined: Mon May 10, 2010 5:45 pm
- Location: Drummondville, Quebec
I use 1oz mat and usually put 5-6 layers, when dry it become strong as hell! After that, just try to push on every spots with you thumb, if it moves, put more. And when you think everything is ok, just try to stand on it as stated above. I weight 175lbs and if mine can hold me, it sure can hold enough power for my system 

He appreciates your support but he aint beggin for it
- str3atwarrior
- Posts: 806
- Joined: Mon May 10, 2010 5:45 pm
- Location: Drummondville, Quebec
Yea but not really necessary unless you're throwing alot of power! But you can make like 2 layers of mat, 1 layer of stitched (weird name, in french it's fibre de verre tressé
) and then finish with 3-4 other layers of mat. Always finish with a mat, not with stitched, as it incorporate with the stitched mat and makes it more stronger... (At least that's what i was shown when i used to work in a fiberglassing shop, maybe someone else can confirm)

He appreciates your support but he aint beggin for it
[rant]
Your fiber glass mat whether its 1 oz, 2 oz, 3oz etc...has very limited strength. The mat is more of a binder and helps with the adhesion of the glass material. You get your strength from the "stitched" or "woven" materials. However using your stitched or woven materials alone isn't a good idea either, unless they have a mat backing stitched in on one side such as a 2408 or 2415 which even so, it is still a good idea to add a few ounces of mat before the material. If you used stitched material without any mat backing on it, or without using a chop strand mat of some sort, you could eventually get shearing between layers of material. Now don't get me wrong, you could use mat only on many applications and it would work just fine. It all depends on what is being built. If you making something like a custom panel for a dash, mat only should be fine. If your making something that is going to have a lot of stress put on it, then some type of material should be used.
[/rant]
Your fiber glass mat whether its 1 oz, 2 oz, 3oz etc...has very limited strength. The mat is more of a binder and helps with the adhesion of the glass material. You get your strength from the "stitched" or "woven" materials. However using your stitched or woven materials alone isn't a good idea either, unless they have a mat backing stitched in on one side such as a 2408 or 2415 which even so, it is still a good idea to add a few ounces of mat before the material. If you used stitched material without any mat backing on it, or without using a chop strand mat of some sort, you could eventually get shearing between layers of material. Now don't get me wrong, you could use mat only on many applications and it would work just fine. It all depends on what is being built. If you making something like a custom panel for a dash, mat only should be fine. If your making something that is going to have a lot of stress put on it, then some type of material should be used.
[/rant]

- NewOldStock
- Posts: 678
- Joined: Sat Nov 21, 2009 10:07 am
- Location: SW Washington