Fiberglass work

[vega]

If one were so inclined to use their fender as a mold for fiberglass what would one put on the fender so the fiberglass would not stick to the fender when trying to remove the piece?

 

I would like to make an attempt to start making fiberglass body parts. Maybe carbon-fiber in the future.

 

Any help ideas etc?

[psdenno]

If one were so inclined to use their fender as a mold for fiberglass what would one put on the fender so the fiberglass would not stick to the fender when trying to remove the piece? I would like to make an attempt to start making fiberglass body parts. Maybe carbon-fiber in the future.

Any help ideas etc?

 

Sounds like you need to do some homework before you set off on this adventure. Here are a couple places to start:

http://www.cstsales.com/tutorials/fiberglass_mold.pdf

http://www.fiberglasswarehouse.com/fiberglass_mold_making.php

Dennis

[Tuyen]

Here is a pretty general outline of what needs to be done when making a mold.

 

1) Clean, buff, polish, wax the part. The mold will literally be a mirror image of your fender, so if you have any scratches and dents they can and will show up. So you want the best finish you can achieve.

 

2) Use a mold release wax, and put on 2-3 layers, this will aid in removing the mold.

 

3) Optional, apply a layer of PVA (poly vinyl alcohol), this is a liquid that dries into a thin film, its added protection from the fiberglass sticking, its also self leveling so it will fill in small imperfections.

 

4) optional, apply a coat of gel coat, this is usually a somewhat thick polyester gel coat, commonly sprayed on using a specialized gel coat gun, but can be brushed on. This layer will allow you to polish and wax the mold and gives a smooth surface to make a part from.

 

Also take note of the shape of the fender, i believe a two part mold will be needed to make a fender. Imagine taking a large piece of cloth and wrapping it over the fender, now imagine that cloth getting hard, will you be able to remove the fender from it? you need a two part mold so it can be taking apart to allow the fender to be removed without damaging it.

 

My friend who does quite a bit of composite work taught this to me, so i learned from watching him but never doing it myself.

 

Alex731 has a build thread on his S30, and he mentioned doing some composite work, so maybe he knows more on the process.

[vega]

Is there anything else I should know?

[gearheadstik]

True Carbon fiber parts are too high to be making.... A real hood is aroung 3k.... Just so u know.. All the hoods u see are one layer of carbon then fiberglass... I am in process of building a 280z dash mold and if it's a part like a fender, you can buy, you should just do that.. Mold making the right way is way more expensive than the part....for large parts that is....

[zero]

The difficulty is definitely in the mold. I'd practice with some smaller parts before trying to do a fender. Even small parts can be pretty difficult to pull a mold from. It will be particularly difficult to pull a piece with all the returns for mounting, ie the areas where you bolt the fender to car.

 

 

$3k is a bit high. JohnC offers proper full CF hoods for ~$1k with the inner frame and clearcoat.

[Six_Shooter]

There are many books available on how make quality fibreglass parts.

 

One that I use for reference is:

 

http://www.amazon.com/Fiberglass-Composite-Materials-Forbes-Aird/dp/1557882398

 

I've made a few fibreglass hoods, and other parts. It can be rewarding, especially if the part you want is just simply not available, or you want something that is completely one off, but the work is not in laying up the part itself, the real work is in making the buck and the mold. When I made a hood for my '85 Buick Skyhawk, I had at least 40 hours into the buck, about another 6 or 7 into the mold, and it there were even steps skipped, since it was a one time use mold. Making the actual hood I have about 4 to 5 hours into.