Mirroring fibreglass door pods..

[celica-fiend]

Hoping this is the right place for it.. didnt appear to fit anywhere else..

very mechanically handy, but have never played with fibreglass before..

Im looking to finally throw one of the component sets I have around into my daily driver.. and didnt want to just slap them onto a slab of MDF and screw it to the door panel.. both for cosmetic reasons and some attempt at staging.. So I thought Id angle the drivers up n over a bit.. then figured, why not play with fibreglass

The biggest hurdle Ive thought of, so far, is how to make the left and right pods more or less identical (angle of mounting etc..) are there any tricks of the trade to do so? or am I just left using my eye, measuring and crossing my fingers as I build them?

any other tips appreciated as well ..

cheers,

brett

[mwmkravchenko]

You need an accurate form to layup the fiberglass onto. That is the first tip.

Accurate as in same shape for each side. Same angle. There are some sneaky ways to do this if you have some experience with the stuff. But if this is the first job you have done make a nice shape carve it out the way you want it to look cover it with wax paper and then fiberglass it up and let it set. The paper is there to act as a release agent between the form and the fiberglass. There are other ways to do the release agent such as thinned out petroleum jelly.

Here is a quick source of ideas that expand on what I started.

http://www.diyautomods.com/forum/showthread.php?p=55

Mark

[celica-fiend]

thanks for the tips, and the link.. great info in that..

Brett

[jol50]

Another way is to make a mold not form it. I've bought cheap plastic bowls at the dollar store and cut them up and taped them together. If you can make it so you can trim each side to an angle and thus make both out of one mold just trim edge to angle it. Or at least make part of it out of something it takes longer to form it all yourself though sometimes you have to. In fact most of the time the plastic bowls that flex some will not stick to the glass...my mixing cups it just falls out of. Sometimes if you put carpet/etc on them they don't even have to look that nice.

[jackinnj]

do wear plastic goggles when mixing the resin --

[tsmith1315]

Creative thinking can be key with making symmetrical objects. Look for defining points that can measured and replicated in reverse.

A couple of methods that could be used to create forms...

-Cut your base and top from thin MDF. This way, you can cut a pair of each and just flip one set over.
-Instead of making flat MDF sides, use small spacing blocks and/or long screws to set the angle of the top relative to the base. (The side will be left open at this point) Again, this is easily measured and reversed for symmetry.
- Use your imagination to create the sides. Aluminum tape, duct tape, or heavy masking tape will follow the existing contours. Plastic, MDF, or other rigid material covered in Bondo will yield infinite shapes when sanded.
-Cover the finished shape in masking tape or other sealing device and a release agent.

Or,
-Create the form from a block of styrofoam. Measure reference points for symmetry as you go along. A metal cutting hack saw blade provides a long, straight, controllable cut.
-Cover this in duct tape, and lay it up.
-Styrofoam offers advantages in creating complex shapes, and in the molding process as well. All sides can be glassed, then the foam plug can be dissolved out with acetone through. With other mold materials, the finished product would have to be cut open, or left with an opening that would allow the mold to be pulled out.

[mwmkravchenko]

tsmith1315 wrote:

Styrofoam offers advantages in creating complex shapes, and in the molding process as well. All sides can be glassed, then the foam plug can be dissolved out with acetone through. With other mold materials, the finished product would have to be cut open, or left with an opening that would allow the mold to be pulled out.

I have never thought of doing that. Really good tip.

Just one note as Jack already stated. Wear goggles when mixing up the resin. The catalyst will injure your eye in a very bad way if you manage to get some of it into your peepers.

Mark

[tsmith1315]

Originally posted by mwmkravchenko

Just one note as Jack already stated. Wear goggles when mixing up the resin. The catalyst will injure your eye in a very bad way if you manage to get some of it into your peepers.

Mark

Use 2 part epoxy resin instead of polyester "fiberglass" resin. It's more expensive, but the cure rate is more controllable, the finished product is stronger, and components are less threatening.

Certainly heed Jack's warning for "fiberglass resin". MEK is the typical polyester resin catalyst and it can cause immediate and permanent damage to the cornea.

[Cal Weldon]

Good advice is you can handle the extra cost of epoxy. Much stronger than polyester.

[jackinnj]

Originally posted by tsmith1315

-Styrofoam offers advantages in creating complex shapes, and in the molding process as well. All sides can be glassed, then the foam plug can be dissolved out with acetone through. With other mold materials, the finished product would have to be cut open, or left with an opening that would allow the mold to be pulled out.

Aaaaaaaaaaaaaahhhh, the "lost wax" process -- with acetone -- it was used by the Etruscii before Romulus and Remus had suckled mama lupa.