cutting fiberglass

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pelican

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I need to cut some fiberglass, but I've never done it. Does it work like metal- cut down then sand finer and finer?
 
pelican said:
I need to cut some fiberglass, but I've never done it. Does it work like metal- cut down then sand finer and finer?
Click to expand...

DId you not read Jean's thread on the fiberglass tank?
 
yeah, but I'm cutting a smaller area, and I need it to be precise and smooth. As far as finishing what's better- files or sand paper?
 
pelican said:
yeah, but I'm cutting a smaller area, and I need it to be precise and smooth. As far as finishing what's better- files or sand paper?
Click to expand...

It's like cutting plastic not metal. Sandpaper is fine. More details can't hurt. :mrgreen:
 
Cutting fiberglass is easy, you can use a saw, a dremel, a grinder, doesn't matter as long as it works. Making a smooth edge is not needed, in fact a rough edge will soak up the resin better and provide a better bond. For small areas, you can substitue epoxy for resin, it will bond just as well and it will be ethanol proof. For a fuel tank repair, make sure the patch is at least as thick as the base material and if you have access to the insides, then you can put a bigger patch to secure the patch to the tank. Everything must be ground down to make sure you are not rying to get resin to stick to crud.

After you are done, sand with finer and finer grits, then paint and clear just like the old stuff. If a part has never been redone, it could still have the gel coat on the outside which is a tough plastic like material. You will never be able to get the same finish if you try to fix a small area, so a paint job may be in order for a top quality finish but I am not a painter so don't take my advice for a paint job.

There are many video tutoprials on fiberglass repairs on YouTube, well worth taking a look before starting.

Take pictures and write it up.

Jean
 
Oh, is in my build thread- I want to cut the reflector sections out of an older style taillight fairing and attach them to the 75 box style taillight fairing. Going to cut out one of these patterns... then paint.
cutting fiberglass


Not sure if I'm going to keep a bigger section or just the round indents. If bigger I'll have to sand the top edges also.
I basically just snapped the back off earlier, and it left a lot of rough and chunky pitting so I wanted to make sure sanding worked. I'll take some pics along the way and post it when it's done.
 
I have a crack in my tailight mount which one day will get repaired using West System epoxy. I will probably reinforce the area on the underside and use fairing compound on the surface (like the West System mixed with Microlight), then sand it to the desired finish. I would then like to use Interlux's two part poly paint to finish it but the stuff is 80 bucks a quart these days and you still have to buy thinner and primer for it. The stuff is bullet proof and gives a wonderful high gloss finish but I havent decided yet that it is worth the expense. The single part poly paints give a wonderful finish as well but of course are not nearly as durable, but I would consider it before I decided to rattle-can the paint. I have had good results with Krylon in the spray can and they now have a paint that is formulated just for plastics. I have yet to get a can and try it, but figure that one of these days I will test it out as it is cheap compared to the yacht paints.

Russ
 
Before you cut up an old tail light fairing, take at look at the cost of a new one - they are not cheap! I would have thought it would be easier and a lot cheaper to built up a mount for a reflector on the box style fairing from scratch!
 
Matt01 said:
Before you cut up an old tail light fairing, take at look at the cost of a new one - they are not cheap! I would have thought it would be easier and a lot cheaper to built up a mount for a reflector on the box style fairing from scratch!
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True, you can make a mold out of fiberglass (make sure you wax the male part so it releases) or even out of clay or plaster, the mate the new parts to the square type light.

Jean
 
ok, so I cut these out by hand with a hacksaw blade, and finished them up on a grinding wheel.
cutting fiberglass

cutting fiberglass


going to epoxy them now, then sand down so the edges are contoured
 
I ended up cutting my tail light fairing with a hacksaw. Made quick work of it. Touched it up with a sander. Worked great.
 
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