Fiberglassing Tips? - Page 8

globalshock · 08-17-2006, 10:58 AM

hey, you know that the bubbles could be the result of traces of a clean up material on the hood. for example. acetone may have been used to clean and smooth the material. if that isnt removed it will cause paint not to adhere to the surface. ACetone has different compostions, most evaporates quickly, like alcohol, whats left ( residue) is just as preventitive for adheration as wet acetone.

Kayon · 10-11-2006, 12:16 PM

First of all, never use Fleece, only Spandex. You should also never use staples and use CA glue and Activator (Can be ordered online from Tower Hobbies.) Fleece when hard is very brittle and anyone who's made a center console or a sub enclosure and tells you their enclosure dosen't have cracks or dosen't flex, or that thier console dosen't have cracks is straight up full of ****.

Cheap **** from Home Depot is a no-no. You should also, while applying use the heaviest Oz glass first, which logically would be 7 oz, then lighter and so on and so forth.

Naamanf · 10-11-2006, 12:55 PM

I don't buy it. If you build it strong it enough there will be no flex and it won't crack. As for staples or CA it's a personal choice. I use both. I like to router an edge and staple the fleece to that.

Another way I avoid cracking is I use white water resin. It's made for making kayaks and won't crack.

Kayon · 10-11-2006, 01:15 PM

I think I know what has warped the minds of so many into thinking fleece is the fabric you should use. Its the magazines.

I was getting my oil changed last year and while waiting there was an issue of Truck'n. Low-and-Behold, this issue had an article about sub enclosures and making it out of fiberglass. They used the classic "prop the woofer rings with dowel rods and lay fleece over it" trick. They used fleece. God Damn, thats where people are getting confussed. They're relying on some hack from "Joe Shmoes Audio Hack Store" (I say it like that cause the name of the shop doing the install sounded like Uncle Bob's Audio Outlet). They used fleece. Then the snow-ball effect occures and people get confussed think, "hey, its ok to use fleece".................................

Wrong.......period.

One thing you should pay attention to is the fact that these articles are put together by a shop. Typically shops have the $$ to buy in all the resin they need to soak that **** properly. If you also notice, the type of curves they are trying to accomodate with the fleece are relatively shallow. A baby could curve them.

You must understand several things.
1) You and I don't have all the money that a shop has resource to which is why, using 45oz of resin is not advantagous. (and if you do you shouldn't be an idiot and buy all that resin to do it the wrong way)
2) You are very restricted to the simplicity of curves as shown in the article. 3) You WILL have a **** ton of sanding involved prior to fiberglassing.
4) Do NOT EVER rely on the strength of the enclosure on the streched fabric. Its only there to create a somewhat solid base for shaping fiberglass. This is why they have S2 glass in the first place.

Other things to note from the article which are huge *** No-No's is the use of power sanders. This article had the guy using a belt sander for crying out loud. Huge F-n no no. It was apparent, at least to my eyes, that the end result was ****ty and was a photoshopped picture of the enclosure prior to primer, as I was easily able to see flaw after flaw with flat spots and the like.

This article was found in I believe the April, May or June 2005 Truck'n magazine. The magazine featured a HUGE yellow H2 Hummer, if you want to research and find the article. I almost stole the magazine so I could scan the pages, but I didn't.

Just keep in mind, that there is no possible way, that you can create the curves as I have by streching fabric if you were to use fleece. You also will never be able to adequately saturate the fleece with 9oz of resin. 9oz is all it took to do the whle sub box I have.

Naamanf · 10-11-2006, 01:31 PM

There is no right fabric to use for every application. I use fleece, carpet, grill cloth etc etc. It all depends on the application.

98EXL · 10-11-2006, 01:42 PM

Quote: Originally Posted by Kayon

First of all, never use Fleece, only Spandex. You should also never use staples and use CA glue and Activator (Can be ordered online from Tower Hobbies.) Fleece when hard is very brittle and anyone who's made a center console or a sub enclosure and tells you their enclosure dosen't have cracks or dosen't flex, or that thier console dosen't have cracks is straight up full of ****.

Cheap **** from Home Depot is a no-no. You should also, while applying use the heaviest Oz glass first, which logically would be 7 oz, then lighter and so on and so forth.

us composites ftw!

JasonWW · 10-11-2006, 01:52 PM

I have a question for you guys.

Lets say you need to build a 2 cu ft enclosure for a pair of 12's. These will be powerful mosters and need a really stiff enclosure.

I can make a square box entirely from 3/4" MDF or make the top and sides from fiberglass to get cool shapes. Once the fiberglass is thick enough to be equivalent to the MDF which would weigh less?

98EXL · 10-11-2006, 01:54 PM

Quote: Originally Posted by JasonWW

I have a question for you guys.

Lets say you need to build a 2 cu ft enclosure for a pair of 12's. These will be powerful mosters and need a really stiff enclosure.

I can make a square box entirely from 3/4" MDF or make the top and sides from fiberglass to get cool shapes. Once the fiberglass is thick enough to be equivalent to the MDF which would weigh less?

the fiberglass.....it doesn't need to be *** thick as the MDF either, and will still be just as strong, and way lighter

JasonWW · 10-11-2006, 01:56 PM

I was thinking 1/4 fiberglass weighed about the same as 3/4 MDF. There's a big difference in density. You think the fiberglass is lighter?

98EXL · 10-11-2006, 02:17 PM

Quote: Originally Posted by JasonWW

I was thinking 1/4 fiberglass weighed about the same as 3/4 MDF. There's a big difference in density. You think the fiberglass is lighter?

fiberglass weighs nothing....resin does

and yes, alltogether, it's lighter

http://www.bwimports.org/forums/showthread.php?t=1413

that's in my trunk....the top MDF sheet weighs so much more than anything else

Kayon · 10-11-2006, 09:46 PM

Spandex, because it is thin it absorbs the resin quickly, unlike that of fleece. This in itself (aside from the fact that fleece stretches no where near as capable as spandex) is why spandex is the preferred fabric. Spandex, also is 75% neoprene and 25% cotton. Unlike T-Shirt material which is 99% cotton. Cotton, is suseptible to heat. We all know this if you have shrunk a shirt in the dryer. The thing to remember here is Resin is a polyester base material. You know its a polyester base material because the hardner is in drop form rather than 1:1 ratio form like epoxy. When resin cures, it generates heat. Whether you feel the heat or not, trust me, its there. This heat, cause cotton to shrink. If resin is used with T-Shirt, the heat generated will shrink the cotton and result in warping of this base layer. Because the hardened stretch fabric is the base of all the consecutive layers of fiberglass, consequently, all your layers of fiberglass will also be warped. Unless you pinch the fabric prior to glassing. And the only way to do that is to 1st identify the fact that you have a warp, and 2nd, drive a screw though the fabric into the below wood skeleton. This pulls the fabric down and reduces the warp but does not eliminate it. This technique is known as pinching. How do you reduce: excessive use of resin, reduce warping, reduce the need for pinching, reduce the need for excessive bondo shaping after fiberglass? 1st thing is first, don't use fleece or T-shirt. Always use spandex.

To attach the spandex to the skeleton is really simple. However, I strongly suggest you apply it in 5" incriments so you can work with the material better. CA glue is basically a super glue. However, you also need somethng called Kicker. Kicker is an activator for the CA glue.
Example. CA glue cures in roughly a minute. CA glue with Kicker sprayed on, cures in roughly 3 seconds. I really am not kidding about the 3 seconds.

Escalade182 · 10-11-2006, 11:05 PM

okay so lets say I'm getting a chop gun soon for a 5.5cfm, 60g compressor...

whats the deal with them? everything at once? perfect layer? just the idea on spitting out chunks of resin-strandmat doesnt produce (in my mind) an (almost) perfect finish...

Escalade182 · 10-11-2006, 11:07 PM

nor the thought of shooting chunks on resin-strandmat at 120 psi at a hardened peice of spandex... I have a feeling that might blow right through it.

Nskforlife · 10-18-2006, 06:45 PM

i'm looking into making custom subs out of fiberglass also. la de da de da... you know how it goes. so i went to hifibuys down the street and asked them what they used to do glass their porsche. check it out here http://www.hifibuysnashville.com/mobile.php

they told me to go so www.selectproducts.com and get the glass and resin and mold cloth and rings there. they told me this cause they said that resin is supposed to be flipped upside down every 30 days or it will seditate at the bottom. and their mold cloth is Really thick and strectchable. so if you wanna save yourself some aches and pains, get the speaker rings, mold cloth, and resin n hardener there. they specialize in it unlike home depot who doesn't even know where fiberslass is located at in the store.

i'm also looking for a review on the 12volt resource.com's resource cd and is it really worth it. thanks.