I picked up a set of JimmyS's side scoops and drilled all the mounting holes last night. Then, I went to grab my dremel and cutting wheel to cut the final few cuts, only to find out that my brother, who used to live with me, had lost EVERY one of my bits. Plugged in the dremel, and sure enough, its also toast.

What is the best tool to use for cutting fiberglass? Should I buy another dremel and the cutting wheel, or just use a coping saw? I haven't used my dremel in over a year, so I don't want to spend another $100 on something that just sits. I'm going to have a few cuts to do on the fiberglass bumper as well.

Also, I plan to eventually build a hood scoop. What is the best tool for cutting the hood?

Finally, what do you guys recommend for finer cuts in fiberglass? (ie: gauge holes in a custom dash.)

All depends on how much access you have to the areas you need to cut. A coping saw would work, but wont fit it tight places. A jigsaw with a medium/fine tooth count blade works good for open flat areas, like the hood. 4" grinder with a cutoff wheel works to, just alot of airbourne dust. Die grinders or dremels are about the best bet for tight areas, use reinforced cutoff wheels, and carbide burrs for tight curves. a rotozip works to, just a bit bigger then the dremel. You can use hole saws for gauge holes if your wanting the round cut outs.

[This message has been edited by Mike Gonzalez (edited 07-22-2009).]

these are the tools I use for cutting and trimming fiberglass.....
Air saw, Fein knife, cut off wheel, 3" air grinder and a DA sander
if you can try to use air tools electric tools will not last long with the dust.
when trimming try to cut as close to the part as you can and then sand the rest this way you will not cut into the part.
D.

For now its just a few small cuts, and relatively fine but not detailed. (just cutting mounting holes and squares for side scoops.)

Air tools WOULD be nice, but I'm not messing with the hood quite yet. . .

Any fine-tooth saw will usually work. A fine-tooth hacksaw blade often works well. For precision work, I've used the super-fine X-Acto saw blades. A carbide grit blade works well in a saber saw, but it has a relatively wide kerf. A bandsaw (even with a wood blade) works very well for larger pieces; a piece of wood used as backing is recommended to prevent tearing on the back side. An ordinary hole saw works well for holes, just work slowly; a drill press is highly desirable because it provides much better control, and a wood backing piece is recommended.

You can use almost any fine-tooth saw to rough cut a piece, and then follow with a hand rasp for final trimming. You can also use carbide "abrader" tools for very fine trim work.

Be aware that fiberglass is highly abrasive, and thus is very hard on steel tools. Carbide tools, when available, will last much longer.

quote Originally posted by whodeanie: if you can try to use air tools ...

I disagree. Air tools are likely to leave an oil film (from the exhaust air) on the fiberglass piece. This oil film will make painting more difficult and may seriously interfere with any secondary (i.e. fiberglass to fiberglass, or fiberglass to metal) bonding required. When working with fiberglass, cleanliness is very important at every step, otherwise you risk future delamination.

[This message has been edited by Marvin McInnis (edited 07-22-2009).]

chris,call me i have the tools needed. i have a dremal and a roto-zip. i put my new mustang skoop and comaro lip on the rear decklid of my 87gt. 419-868-6504.

quote Originally posted by Marvin McInnis: I disagree. Air tools are likely to leave an oil film (from the exhaust air) on the fiberglass piece. This oil film will make painting more difficult and may seriously interfere with any secondary (i.e. fiberglass to fiberglass, or fiberglass to metal) bonding required. When working with fiberglass, cleanliness is very important at every step, otherwise you risk future delamination.

You're using too much oil in your air tools.

quote Originally posted by Archie: You're using too much oil in your air tools.

You're probably correct , but all of the oil that goes into an air tool eventually comes out in the exhaust. In aircraft industry practice, the use of oil-lubricated air tools is generally prohibited in the same room where structural composite (e.g. fiberglass, carbon fiber, etc.) pieces are being fabricated. I realize that cosmetic automotive parts may (or may not) be a different matter.

[This message has been edited by Marvin McInnis (edited 07-22-2009).]

An Angle grinder,with a 4 1\2 inch cut off wheel.Cost is about $15 to $20 for the angle grinder and about $6 for the cut off wheels (Im not sure if any cut off wheels are included).I baught mine from Harbor freight tool and I think they have an on line web sight or try your local Home Depo or Lowls.

As a note of safety precaution the Dremel Cut off wheels (brown) can and will fly appart.Harbor freight sells Dimond Coated Metal cut off wheels that fit the Dremel.
Foresight is better than no sight....

[This message has been edited by James Bond 007 (edited 07-22-2009).]

quote Originally posted by James Bond 007: As a note of safety precaution the Dremel Cut off wheels (brown) can and will fly appart.

Correct. It took me forever to figure out that it was OK to stack two or three cutoff discs on the Dremel mandrel. This increases the kerf width, but it greatly increases resistance to the discs shattering.

a shop vac in your other hand or in a helpers can greatly cut down F/G ''dust'' in the air and on you
and that mix of resin and glass bits is nasty
eye protection and a good respirator [ not a cheap dust shield] is a must
as is a throwaway suit or old clothing

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Question wonder and be wierd
are you kind?

quote Originally posted by ray b: a shop vac in your other hand or in a helpers can greatly cut down F/G ''dust'' in the air and on you and that mix of resin and glass bits is nasty eye protection and a good respirator [ not a cheap dust shield] is a must as is a throwaway suit or old clothing

I'm just using a cheap throw-away. I'm not doing a TON of fiberglass work. Literally drilling out a few holes and cutting a few 1 inch cuts. 1 time, and then I'm done. Is this stuff really THAT dangerous? I got some on my leg last night. It itched, but washed off and was fine.

For the little areas that you need to cut, I highly suggest a dremel. They make dremel cut off wheels that have a spring loaded speed adapter that work great for what you are doing.

The cheap throw away mask if fine for the little amount of stuff you are doing. Fiberglass will make you itch, it's the nature of the beast.

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Click here for all your Fiberglass part needs

If you have a jigsaw handy, a medium metal cutting bit should do fine. You can also use a drill to make a starter hole for the jigsaw, if necessary. A standard drill bit at low to medium speed will work for that.

And BTW you can get Black & Decker rotary tools (basically the same thing as a Dremel) for about $30 or so at most hardware stores. The black reinforced cutoff wheels work really nice on fiberglass.

quote Originally posted by JimmyS: For the little areas that you need to cut, I highly suggest a dremel. They make dremel cut off wheels that have a spring loaded speed adapter that work great for what you are doing. The cheap throw away mask if fine for the little amount of stuff you are doing. Fiberglass will make you itch, it's the nature of the beast.

I will second the spring loaded EZ Lock cut off wheels. They work great and they don't fly apart like the thin brown cut off wheels.