Saw for cutting fiberglass skins off

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FloatingMoneyPit
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Saw for cutting fiberglass skins off

Post by FloatingMoneyPit »

What's the best way to cut off skins for a recore? 1/8" laminate.
I hear the Fein tool is ideal, but it's out of my price range. I have a cheapy 7 1/4" circular saw, which I guess is the fallback. Probably my least favorite power tool, though. What type of blade would cut fastest & cleanest in glass?
Any other possbilities...drywall rotozip type tool, special router bits, grinder?
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Tim
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Post by Tim »

I sure like my 6" circular saw. This is good for all but the tightest areas.

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I have also used a Rotozip with some success. The bits tend to break frequently, so a good supply is helpful. I have always had trouble finding decent bits; there is a type available that touts itself as for use in fiberglass, but in my area they've been few and far between at the stores. The thinner the fiberglass, the better this tool will work. It's also good for finishing up corners left behind when using a circular saw to cut.

Carbide blades will work best in any tool, when available.

An angle grinder with cutoff wheel will also work well, if you're used to using one.
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Ric in Richmond
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Post by Ric in Richmond »

If you were working from above deck must any circular saw would work. From below deck it gets complicated fast due to access.

The amazing thing about the fein is its ability to get into places you would never be able to get ANY tool into to cut.

It may seem expensive, but if you put any value on your time at all it may be the least expensive tool you buy.

Barring that I bet something like this would be great:

http://cgi.ebay.com/MAKITA-CORDLESS-CIR ... dZViewItem
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Figment
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Post by Figment »

I used a circular saw and finished the corners with a hammer and chisel.
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Post by Jason K »

All of the above posts are great advice. I'll just second some of the ideas. If you are removing the skin from above, a circular saw will be the fastest and easiest tool.

From below, the circular saw is hazardous and unwieldy. The Multimaster is really the best tool for that job. However, if you don't want to spend the bucks, you can get a Dremel tool for about $70 that will do the trick. The dremel is slow and you'll go through bits very quickly. I found the round cutting discs to be the best for cutting the glass. Wear eye protection (!) as the shattered bits tend to explode. Also, use a permanent marker to draw the pattern for where you're going to make your cuts and take your time. It is easy to swerve off path if you get in a hurry.
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Ceasar Choppy
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cutting core

Post by Ceasar Choppy »

A hearty second for the Fein Multimaster.

Not only does it cut through FG like butter, it won't cut you. And you can use the scraper tool attachment for scraping out the balsa which is harder than you think to get rid of.

That tool and my 5 lb. sledge hammer are probably the most important tools I use... LOL. And I use the Multimaster a whole lot more!
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Post by bcooke »

I follow the path of my seniors (on the forum). I mostly use a circular saw with a fine toothed carbide blade. Like Tim, I have a Rotozip, which I hate, yet it is sometimes the only tool that can get the job done. Finally, I have a 'special' chisel that I use quite often. Sometimes just lining up that battered chisel and whacking hard is the best trick in the book.

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One more question...

Post by FloatingMoneyPit »

Thanks for the quick input, guys. I worked my way up, from Dremel (too slow and agonizing, waiting for the bit to break and give me a 3rd nostril), to angle grinder, to circular saw. The circular worked fine, but I ended up sticking with my "Firestorm" 4.5" grinder with a metal cutoff disc. Worked so well I only needed one hand most of the time. It cut fast, the weight of the tool helped it sink into the laminate, and it pulled itself along nicely. My cut lines aren't perfectly straight, but c'est la vie.

One more q: how hard was it for ya'll to pry the top skin off once the cuts were made? My Tartan 27 appears to be ply cored. I started prying off an initial 2x3 piece on the foredeck and it isn't easy going. I guess I had delusions of balsa-turned-oatmeal with zero bond to the skins. Like sugar plums dancing in my head.
But it isn't dry enough that I'm comfortable leaving it alone.
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Post by Tim »

Plywood will usually be harder to remove than balsa; as bad as the plywood gets, it doesn't necessarily turn into mush the way balsa does. Also, core can be wet but still soundly bonded to the skin, which sounds as if it may be in your case.

Refresher course: wet core does not always mean that it has become debonded. Debonding does not always mean that the core is wet. And debonding is a different thing from delamination.

Whatever the case, it sounds like you have an unsavory job ahead. It's no fun removing core that isn't quite ready to give up its fight! All you can do is plug away, and take care to avoid damaging the skins. Try to peel the plies of the plywood apart, leaving one or more plies on the top skin, rather than removing the bond at the top. Later, when the skin is removed, you'll have no trouble scraping and grinding the remaining plies off.

In my case, the balsa core was so bad, and so debonded from the skin, that the skin actually "jumped" free when the cuts were complete; except for a small area where the core was still sound and well stuck to the deck, removal of the skin was very easy.
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Ceasar Choppy
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plywood core

Post by Ceasar Choppy »

Depending on whether the plywood is mush or not, you might try DRYING it out. This might take you a while, but if you are not in a hurry, it is the path of least resistance and perfectly acceptable. I know folks who did this to a large bridge deck on a trawler about 6 years ago with no problems at all. It was infinitely easier than trying to remove plywood still bonded to the bottom skin.

You need to be sure that the ply is still structurally intact though. Use acetone to help dry out the wood. Coat with plenty of epoxy so that it doesn't happen again-- assuming of course you've fixed what was leaking into the core in the first place.
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Post by JetStream »

Don't sell the Dremel short. I have a Multimaster and use it for some jobs but have found cutting a fiberglass skin is sometimes a piece of cake with the Dremel. You have to use the fiberglass reinforced abrasive wheel, but with that, it cuts like butter. Certainly not the speed of a circular saw, but a lot less material removed as well.
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Right angle grinder

Post by Dan H »

I used my right angle grinder with 1/16" thick wheels. Worked like a charm.
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