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DHeal 03-11-2012 06:04 PM

Tip: Cutting Fiberglass Parts
I just finished making the initial cuts on my various RV-12 fiberglass parts (tail fairing, cowl, etc.). I used my cheapy Craig's List Skil bandsaw with excellent results. Here's how I did it: I carefully ran dark masking tape along the mold cut lines - on the outside surface of the fiberglass. I made a saw blade kerf guide out of a scrap piece of clear plastic. I backlit the kerf guide from underneath the saw table using a small worklight. Now I could easily see the saw blade and its relationship to the masking tape through the translucent fiberglass. I was able to accurately guide the fiberglass piece so that the blade cut within 1/16" of the masking tape. Worked great for me -- be very careful, no cutting of fingers permitted!

ps -- You may want to have a trusted associate help you hold the large lower cowl piece as you maneuver it through the saw.

jersey 03-11-2012 06:37 PM

Also Try Diamond Dremel Wheel
For sharp radius, angles and non flat pieces etc. try the dremel diamond wheel. Cuts like butter.

Gary Eldridge

Bill_H 03-11-2012 08:23 PM

The dremel with a small abrasive disk is the SUPERIOR tool for the fiberglass pieces!!! Also borrow or get a 4 inch bench mount belt sander - the kind where the belt is horizontal with the rounded end exposed. You can very easily make straight and curved lines right up to the scribe line with great control and much faster than hand sanding. I think you have better control with the big pieces using it than a saw. Use coarse paper.

whittfic 03-12-2012 02:56 AM

Fibreglass is very abrasive and hard on band saw blades. Extended use will quickly take the edge off steel blades and drill bits.

Clive Whittfield

Geico266 03-12-2012 05:57 AM

Make sure you wear a dust mask or respirator when working with fiberglass. The fiberglass dust is now classified as a potential carcinogenic. Do the work outside if you can and avoid bringing dusty clothes into your house. If you use an airhose to blow the dust out of the shop wear a mask. It is better to use a vacuum with a good fine particle filter, but wear a mask also.

DHeal 03-12-2012 10:58 AM

I forgot to mention in my initial post that one of the benefits of using my band saw for these cuts was that I could easily hook up my shop vacuum to the band saw and vacuum away most of the fiberglass dust while cutting. Always use a mask -- that fiberglass dust is nasty stuff. I agree that the Dremel tool with cutting wheel works -- especially for the curvy cuts.

Phillik 747 04-04-2012 08:37 AM

Perma-Grit Tools are made of Tungsten Carbide Grit. These cut through fiberglass like it isn't even there. And they last unlike the dremel disks.

Gandalf 03-01-2017 03:18 PM

Anyone tried to use the dremel vacuum powered cutter that vacuums up dust and is powered by a shop vacuum to trim the engine cowling?


snopercod 03-01-2017 04:04 PM

structured carbide bits
I used MANY of these Structured Carbide Bits when building my fiberglass airplane. You can use the long, pointy 9935 like a roto-zip tool. They work great!

wjb 03-01-2017 08:25 PM


Originally Posted by Phillik 747 (Post 646396)
Perma-Grit Tools are made of Tungsten Carbide Grit. These cut through fiberglass like it isn't even there. And they last unlike the dremel disks.

Good to know! I destroyed about 6 Dremel disks this past weekend working on the wing tips.

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