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Sidewall fiberglass project

2662 Views 35 Replies 12 Participants Last post by  DaveUSDMkillr
Well I started my first subwoofer box and here are pics of the tape work. I hope later tonight to start the resin process.

The photos do not show the entire taping process done, but with my current layout the subwoofer will be facing the pass rear seat and be just about centered behind the pass rear seat.

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Ok I painted the resin/hardener onto the tape then applied my first layer of fiberglass cloth. Applied another resin/hard. 2nd layer of fiberglass cloth then another layer of resin/hard. I had a little trouble getting the first layer of fiberglass to stick, but adding lots of resin/hard allowed the first layer to hold nicely.

Right now I just hope 120 yards of masking tape is enough to protect my trunk panel. Tomorrow I will be adding another two layers along with the subwoofer ring and rods to hold it in place. I really want to get the rods into the fiber glass.
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Keep us updated with pictures, I'm interested in how this project turns out!
Well I left the panel and two layers of figerglass in doors with climate control. Kept the humidity down and I checked on it today. Two layers have turned out to be really strong. So after the lumber shop is done with my sub ring I am going to fit the wood rods and tac everything into place with liquid nail.
Just curious... Your sub box walls will be made of only 2 layers of FG? What size sub? How many watts will it be receiving? How heavy is it? I'm not a pro FG'er but I wouldn't think that only 2 layers would be strong enough to:
-support a heavy sub
-support multiple subs
-support the internal/wall flexing caused by a powerful sub

I'd hate to see it crack under load after all the work you have done or especially after it has been painted/covered. Might be worth another layer or two to be safe :dunno:
No I just have two layers right now. The "mold" will have five layers. three layers after the wooden rods are in place. I will use poly/cotton for the first cloth to give me form. Then six or seven layers on top of that.
Right now I am just posting everything in steps.
:yesway: Good to hear :)
Looking good man! Nice to see you decided to go w. the side desing we were talking about. How much did the wood shop end up wanting for the rings anyway?
$20 and I drilled the holes for the screws already. Right now getting my wooden rods "tac" into place is proving hard.
Yea I ran into a little difficulty here too. It didn't seem to want to stay on the fiberglass!
If you can, always lay up all your layers while they are still wet. This allows the piece to dry as one instead of one drying, and then the next layer, and so on to be only mechanically bonded to it. Polyester is pretty weak, and laying it up all at once is almost a must with it.
Well I got two wooded rods deep in resin/cloth. The rest will go under one more layer which will make the "mold" six layers.

For thos eof you who are wondering what my sub ring looks like. There is also pics of what pure resin/hard looks like. AS you can see it craps smoothly along the stress line. Which is why we need fiber cloth I guess.
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No pics this time sorry. I removed the "mold" from the car's trunk panel. No problems removing it and thank god the trunk panel is fine. I stood on my scale and then applied force to the top of the mold. I removed about 180 pounds from the scale and the mold did not flex at all. I applied 50-80 pounds on the two wooden rods and no flex or movement. Later today I will clean up the sides of the mold and try to find a way to mount the sub ring. With it only being 1/2" thick I don't think I can run a screw through the ring and into the wooden rods. My biggest issue up a head is laying the fleece and other wooden rods to allow a nice flow with the finished look and provide support for the sub.
Went out and got 3yards of poly/cotton along with more masking tape. I don't feel like dicking around with setting the next "mold" up today so I will prob continue tomorrow. Right now I am looking at using the tape and poly/cotton to create the final rough shape of the box.
Looks good so far. :)
WTF is that supposed to be? :lol: Anyways, sounds like your "box" is pretty strong and rigid! Lets hope all goes well with the ring mounting! Keep us posted...
That pic is showing fiberglass res/hard with no cloth. I wanted to show what happens when resin/hard is flex. Smooth non rigid crack.

More pics up later today. When I get back from my VA exam I plan on finishing the rear mold. Then doing the lower mold for the sub ring. With these two molds ( two layers) I will be able to lay the ploy/cotton and finish this up.
If I want to do bondo over this to paint it is there any prep work I need to do to apply bondo?
I would sand the surface to be bondo'd with a low grit in order to score it and create divets for the bondo to "grab" onto. Also, don't forget to clean the dust off with alcohol or similar (and let dry) before applying something to it. I would definately not apply bondo to a smooth surface (like resin).
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