cutting fiberglass

[ppd1107]

The PO of my jeep put a fiberglass hardtop on it from a different year. It works ok but the rear window has two lips on it that close on either side of the tailgate which means that once the tailgate is closed, the rear window can't be openned. I plan on cutting off the inner lip so the top can be openned without openning the tailgate. What meathod and tools should I use to cut a straight line and cut at the correct depth so I only take the inner lip of the rear window?

 

[Sasquach]

How about a router? you would need to make a guide to get a straight line. Can't think of any saw off hand that would have any depth control. Wear a mask whatever you do though.

 

[IOPort51]

I would use a die grinder with an abrasive cut off wheel. I would wear long sleeved coveralls, a respirator, and goggles with a hood and gloves. I would dress a friend the same so they could hold the vacuum to suck all the dust in. And when I was finished I would very carefully remove these cloths and emedieatly throw them all in a trash bag and then into the can they would go. I have never found anything that will itch more or longer, we are talking months, than ground fiber glass.
Have fun.

 

[BrockGrimes]

Cut off wheel also tape off the surrounding area.
And cloths as described.

 

[ppd1107]

Would one of the ocitating muti tools work? It seems like there would be less dust

 

[Jason S]

I worked for a company that made fiberglass tanks for a very short while. They had me prep the sections to be joined with a die grinder. I tried everything imaginable to keep the dust off my skin, even vaseline. The vaseline only made more cling and eventually get in my pores. The 'best' way to get it off your skin after the fact is with Lava soap. But remember, if you grind fiberglass with a phneumatic grinder, you will get covered in fiberglass particles and you will be miserable for at least the next few days.


I recommend a razor saw. Should cost $5-10 at a local arts and crafts or hobby store. It's essentially a hack saw, but it has a really thin, 6 inch blade. It's designed for cutting acrylics and hardwoods for hobby type aplications and will make short work of fiberglass. It's not electric or air powered, so it will be easier to control how much you remove and how quickly you generate dust.

Use a masking tape to build a guide line to cut along. it only requires one hand to operate so you can use the other to operate the vacuum as necessary, but it wont send dust flying like a grinder.

Whatever method you use to cut the tab, remember to use a liquid adhesive to seal the now exposed fiberglass on your top. This will help keep your top from delaminating at the exposed cut from the wear and tear of operating your hatch. If you are careful, very careful, you should be able to use crazy glue for that. Otherwise a very small dab of a 5 minute epoxy will work.

 

[BrockGrimes]

Good advise Jason

 

[priceg]

How about one of those disposable painters suit?

 

[Jason S]

A disposable paint suit will help. Especially if it's the kind with the hood that makes you look like an Oompa Loompa. Get at least a size larger than you think you need so that you have room to move around. Take some duct tape and go around each wrist and ankle to help keep dust outside the suit. Just wash which ever clothes you wear underneath seperately from anything else.

 

[54cj3b]

good cut off wheel
good respirator
gloves and suite
goggles
and your good to go

cold shower when done to get off any fiber glass before it gets in the pours damn it now I'm itchy

 

[ppd1107]

I'm not sure the razor saw will work. The lip is something like four feet long. I like the idea of not getting fiberglass dust everywhere but I don't have a week or two to saw on the door.

 

[ken98k]

Why not go low tech and use an old fashioned hand saw?
If you use a fine tooth saw you can get a very nice cut and only a fraction of the fiberglass dust in the air or on you.

 

[73CJ]

If you could put a pic of the lip, that would sure help with the tips. Make sure you don't cut a seam and the pieces will fail. There may be a reason for the lip.

A belt sander with a 36 grit will cut it fast. I just jump in the shower right after. Can you do it outside? A shop vac will get most of it with a helper.

A straight router bit will follow the edge perfectly. Use a straight carbide bit with a bearing on the end.

Do wear a respirator though. You can't cough the stuff out.