[bzdel2441]

I have a fiberglass speaker box that I bought through a GB on this board and I am not that happy with the fiberglass (very thin, areas where there is only 1 layer) job so I am wondering if I can just add additional fiberglass layers over what is existing?? And if so is there any special procedure??

Also there is a crack in the bottom of the box that goes about half way through the fiberglass (its THICK on the bottom) is there a paste or anything I can use to fill that in, or just fill it in with like resin??

Thanks
Chris

 

[mattleegee]

Its easiet when just adding layers, the mold is in place already that is the hard part

You can buy those cloth sheets and resin
Or you can buy a jelly resin and just paste it on top and sand it down to make it smooth

 

[geewhizbang]

You could just get a can of Bondo Hair and line the inside of the box.

 

[dehoff]

[quote author=bzdel2441 link=topic=69942.msg1217454#msg1217454 date=1171926837]
I have a fiberglass speaker box that I bought through a GB on this board and I am not that happy with the fiberglass (very thin, areas where there is only 1 layer) job so I am wondering if I can just add additional fiberglass layers over what is existing?? And if so is there any special procedure??[/quote]

What you want to use is fiberglass mat, with resin. Do not use the cloth (aka woven roving), as it does not have the strength that resin impregnated mat does. You'll end up mixing the resin with the catalyst, and then "painting" it onto a piece of mat that you have placed on the enclosure. I used quotes over painting, as it's more of a stipling action than actually painting (it helps if you use a paint brush with bristles that have been cut off a bit, making them a little stiffer). You want to saturate the fiberglass mat with the resin, but not use any more resin than necessary to fully wet the mat. Once you have that layer wetted, throw another piece of mat on and wet that one out, repeat again. Let dry.

Also there is a crack in the bottom of the box that goes about half way through the fiberglass (its THICK on the bottom) is there a paste or anything I can use to fill that in, or just fill it in with like resin??

Thanks
Chris

Merely filling that crack with Bondo or resin is asking for trouble. The strength of fiberglass comes from the filaments in the mat, and resin by itself is fairly brittle. If there's enough space in the crack, you'll want to try to get a little mat into the crack and then I'd apply at least three layers of mat on each side. If it's just a hairline crack, you'll probably just have to apply the layers of mat on each side and hope for the best. Make sure to extend the new layers of mat well past the ends of the crack.

btw- be VERY careful when handling the resin catalyst. MEK Peroxide is some nasty stuff- wear eye protection!!

 

[crazyfast]

and get a professional air filter mask while ur at it (appropriate term? :dunno i wound up shelling out for one ($30) after i almost passed out while making my custom sub box... oh, and do it outside... learn from my mistakes...

 

[geewhizbang]

I didn't say "Bondo" by itself. I specified "Bondo Hair", which has a great deal of fiberglass in it.

It might be a little better to actually use a fiberglass mat and resin, but the Bondo hair is really strong, and it is a lot easier to apply inside a box.

As for the crack, if you fill that with resin and put a layer of Bondo hair over it or fiberglass mat, it should be fine.

 

[bzdel2441]

sounds good guys I just got a small pint/quart (whatever it was) of the bondo hair.. I think it should work fine....

 

[dehoff]

[quote author=geewhizbang link=topic=69942.msg1218572#msg1218572 date=1171987639]
I didn't say "Bondo" by itself. I specified "Bondo Hair", which has a great deal of fiberglass in it.

It might be a little better to actually use a fiberglass mat and resin, but the Bondo hair is really strong, and it is a lot easier to apply inside a box.

As for the crack, if you fill that with resin and put a layer of Bondo hair over it or fiberglass mat, it should be fine.


[/quote]


It's still not as strong as fiberglass mat, and I wouldn't trust it in a sealed enclosure. That's why the Bondo hair, or kitty hair, is typically only used on trim pieces to smooth out the underlying fiberglass mat.