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Discussion Starter #1
Hello,

I'm trying to make a removeable fiber glass mold that would cover my speaker box so that i can paint it and make it look a bit sharper than just having a regular gray carpet covered box. (it would mimic the C5 waterfall cover behind the seats)

I have fairly limited funds so economy is a consideration. But from the basic knowledge I have learned so far, I believe this can be a fairly simple project.

I guess all I need is a roll of fiber and some resin. But what do you recomend?
Then I think the next step would be to cover the box with plastic "(so that it dosn't stick to the box), mix the resin and just lay out strips until the entire box is covered. Then once it hardens slide it off, rip out the plastic that is stuck to the inside of the mold, and then do some major sanding.

How long does the mold normally take to dry before I can handle it?
What is this roller thing i hear about and what kind should i buy?
Any tips on easy ways to soak and apply the resin and fiberglass?
Can I pick up most of my supplies at a local auto store and how much would i need for approx. a 3' by 4' total surface area?

Any information and advice you could provide to get me started with my project would be greatly appreciated.

Jason Browning -18th Military Police Det.
 

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I'm not sure what your box looks like but it sounds like you have the basic concept down. I wouldn't try covering the box in plastic. The styrene monomer in the polyester resin will attack most plastics and you may end up with more of a mess that you can imagine. If the box is wood, I would cover it with a coat of Vaseline. Doesn't need to be slathering in it, just well coated. Then smear on a thin but complete coat of Bondo. The Bondo will not stick to the Vaseline and will pop right off when you are ready. Finally put 4 layers of the hardware store fiberglass mat with resin over the Bondo and let it set. If you can put it in the sun to cure, it will take only an hour or so. The stuff seems to set right up in UV radiation. In a 70F shop it may take half a day to set. If it sets overnight, it will be hard. All you need to do then is pop it off the box and give the wood box and the new fiberglass box a wash down with lacquer thinner to get rid of the Vaseline.

You don't need any fancy tools for this job. Just a coffee can to mix the resin in, a stirring stick and a 2" chip brush (cheap $0.79 paintbrush). I have had two of those fancy rollers for 20 years and have never used them and I have made MANY car parts. Cut or tear the cloth to shape, mix the resin to spec, paint on a thick layer of resin, put on a layer of cloth and tap and paint it with the brush to wet it clear through and get out the air bubbles, keep at this 'til all 4 layers are on. Get some acetone to clean up with 'cause you will be a sticky mess when done, guarantee.
 

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vaseline eh? interesting. Willys knows his stuff for sure.

I did a few small parts for my truck, I used aluminum foil to cover the original part really well, then I brushed I light coat of the resin on the aluminum foil, then I put strips of the fiberglass matting on, and brushed on more resin.

I think you will find if you brush a light coat of resin on first, it will help the mat to stick to the piece...The matting has a tendancy of turning to sludge when you get alot of resin on it...

I think the instructions actually say that you should completely submerge the mat in a tray of the resin...I have not had good success with this, it falls apart and turns to mush.

good luck...vaseline eh?
 

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Troll Hunter
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I've made molds using cardboard and bondo with parrifin spread over it for release agent, someone recently told me they used Pam or another of those spray on cooking products.
 

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Great responses to all fibo questions, willys- what a 'knowledge base' in one person- we are Lucky to have you on the board (and I mean this!!!) Also remember, SnapCase, that matting and cloth is available- with larger parts I'd suggest the cloth as you can cover a larger area and make it smoother. Fibo works great for speaker boxes- I made the ones in my 'J. Don't rush cure time as it gums up the sandpaper, but willys is right on- about an hour in the sun!! Fibo=Fun!!
 

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Yeah, every time I've ever saturated the matte first, I either got bubbles in it or it tore apart. The roller is OK for flat surfaces but no good for getting into tight corners. I mostly just use paint brushes, you'll develop a technique that minimizes bubbles pretty quickly.

I thought I was the king of using crazy stuff for molds, but you win, Willys! Vaseline?? I bet that works like a [email protected] Just don't get any sand in it, huh? :)
 

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Mold wax and PVA are still best for fine mold making but for the type of molding SnapCase is doing, Vaseline is perfect. Can't really wax bare wood or other rough molds and my experience with wrapping them in tin foil, etc. has been disappointing. Tin foil can separate from the underlying mold and cause innaccuracy and the resin always seems to seep under the foil and stick everything tight.

The key to this method is the layer of bondo between the Vaseline and fiberglass. 'Glass resin may penetrate the grease and stick the part but Bondo is so repulsed by it that the parts literally fall apart when de-molding. also the Bondo seals the whole mess so resin cannot seep into the underlying mold.
 

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Discussion Starter #8
What about just stripping the carpet off the box and covering it with bondo and then just painting the bondo. Technically all im trying to do is heighten the appearence of the box. I want to do this by painting it. Painting particle board just dosnt work. so i thought i would cover it with fiberglass and paint that. but now im thinking bondo would be easier and less messy. is it possible to get a good smooth paintable finish if i just smear bondo over the wooden box and then sand it smooth?

thanks jason
 

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I do hope you mean MDf board and not particle board. Particle board will begin to fail after a certain amount of time.

Willys gave you some good advice - never thought about using vaseline.

As mentioned, you can use Pam or other brand cooking spray as well.

I have used the aluminum foil but had varied response...

I mostly just use masking tape and a good coat of wax or lard. If you do that, make sure you have planty of tape overlapping.

And to answer your last question, you don't even need to bondo the box if you just want to paint.

Go to <a href="http://www.soundillusions.net" target="_blank">www.soundillusions.net</a> and do a search for painting boxes. I think they even have a tutorial in their on-line magazine.

Good luck and keep us posted
 

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The Smell of Nitro in the morn
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Here's a site on fiberglass and info on products.
Epoxy smell's a lot less than polyester resin.
<a href="http://www.fibreglast.com/infocenter.php?session=62431a6f39056c53d2588829e83a5f5d&PHPSESSID=62431a6f39056c53d2588829e83a5f5d" target="_blank">http://www.fibreglast.com/infocenter.php?session=62431a6f39056c53d2588829e83a5f5d&PHPSESSID=62431a6f39056c53d2588829e83a5f5d</a>
 

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Originally posted by SnapCase:
<strong>What about just stripping the carpet off the box and covering it with bondo and then just painting the bondo. Technically all im trying to do is heighten the appearence of the box. I want to do this by painting it. Painting particle board just dosnt work. so i thought i would cover it with fiberglass and paint that. but now im thinking bondo would be easier and less messy. is it possible to get a good smooth paintable finish if i just smear bondo over the wooden box and then sand it smooth?
thanks jason</strong><hr></blockquote>


This would give you a good smooth surface but the wood underneath isn't very stable and the Bondo would eventually crack. If you want to use the boxes and just get a smooth finish, I would still put at least one layer of fiberglass mat and resin over the boxes to give them a stable surface then Bondo, sand and paint. That would last forever.

[ May 24, 2003: Message edited by: [email protected] ]</p>
 
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