Cutting fiber glass
- Thread starter Mic Jones
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I found the best tool(s) to be an angle grinder and/or Dremel tool with a cutting wheel (depends on how much cutting and how precise you want to be).
Thanks, I have both. So far I've been using a wood saw 12 inch wiith one rounded end normally used in cutting installed panels or floor boards. It worked ok but needs a lot of effort and blunts the saw. I have to remove most of the aft birth trays to get at a leaking ballast tank.
What kind of cutting wheels did you use on the angle grinder?
No doubt running the shop vac when cutting would help minimize dust.
I have found cutting discs on the angle grinder to work best on straight line cuts and a rotary burr on the Dremel for any work with curves. I have not tried the dremel disks but they may be OK on more gradual curves.
My angle grinder is an old but good Makita 4 1/2" and I used 2.5mm thick Flexovit discs - slice through the fibreglass like buttter. The spindle arbour is 2mm thick and thus won't take the 1mm discs (I assume the newer machines must have a thinner abour). I suspect the thinner the disc the better. Look for disc suited to cutting fibreglass.
I invested $70 in a decent respirator and also wear strong protective goggles. It is a good idea to surround the work area with lots of wet cloths (old sheets work well) to keep the dust down and have a vaccum going near to the cutting disc. Cover yourself up as much as possible if you want to avoid lots of itching.
My angle grinder is an old but good Makita 4 1/2" and I used 2.5mm thick Flexovit discs - slice through the fibreglass like buttter. The spindle arbour is 2mm thick and thus won't take the 1mm discs (I assume the newer machines must have a thinner abour). I suspect the thinner the disc the better. Look for disc suited to cutting fibreglass.
I invested $70 in a decent respirator and also wear strong protective goggles. It is a good idea to surround the work area with lots of wet cloths (old sheets work well) to keep the dust down and have a vaccum going near to the cutting disc. Cover yourself up as much as possible if you want to avoid lots of itching.
One of those dodads the cut by moving back and forth work great with little dust.
I wish I knew what they are called, better yet I wish I had one.
I wish I knew what they are called, better yet I wish I had one.
Is this what you mean, tb?
http://www.harborfreight.com/oscillating-multifunction-power-tool-68303.html
http://www.harborfreight.com/oscillating-multifunction-power-tool-68303.html
Cruiser 1 Thanks I have all the equipment you mentioned. A Dewalt make. Also thin and thick discs for welding and masonary jobs, will try both and also look for fibre glass ones. Cutting one inch above the ballast tank will need a steady hand with the cutter guard resting on the fibre glass
Have good repirator etc. I needed to know what you said before I tackle a trade that wasn't mine. Like the idea of laying down wet drop sheets. Wife's out maybe she won't miss a couple off the bed.
Haven't seen those recip saws so will go to a body shop or tool place and ask about them. But have to get on with the cutting today with what I have.
Time bandit liked your description.
Thanks all
TB, sounds like you're talking about a sawz-all. They certainly will cut, but without a steady hand they can be brutal.
When I "sliced and diced" my 25, I found that the thin metal cutting blades worked remarkably well in most areas. They only suffered when they had to cut through an area with the plywood core (such as the deck).
I believe I misspoke earlier when I mentioned the cutting wheel on the Dremel. That reference was for the angle grinder. The other post had it right...
Finally, depending on the depth and complexity of the cut, you may want to try a jigsaw set to a shallow blade depth, with a fine-tooth blade.
I really like my Dremmel Multimate for cutting fiber glass. I bought the copy from Harbor Freight to keep on the boat. It cuts quickly. accurately and with little to no airborne dust.
I did it was disaterous. Couldn't sink the blade to the base so had it at an angle. Tried various blades even ones I had cut short. It shattered the gell kept jumping out breaking the blades and I couldn't keep a straight line. Two tools I stay away from as much as possible. Hand held jig saws and routers, other than dremmels. I will post progress or otherwise.
I'll try the Dremmel first to see how it does but I have a large aea to cut out
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That would be the dodad.
I guess if I only had an inch to work I would use the Drmel tool with a small diameter (1inch) cutoff wheel but know the wheel breaks easy.
I guess if I only had an inch to work I would use the Drmel tool with a small diameter (1inch) cutoff wheel but know the wheel breaks easy.
Sorry Mic, I should have mentioned that it is a good idea to put gaffer/masking tape on the area to be cut and draw your cutting lines on the tape. I actually used Nashua Gaffer's 357 gaffer tape (made by Tyco Adhesives). It is the most fantastic gaffer tape know and will stick really well. When I cut the bench top out to install a flush mount Origo stove there was no chipping of the gelcoat at all using a 2mm disc on the angle grinder. A 40m roll of 48mm Gaffer's 357 costs about $15 out here but is probably much cheaper over your side of town.
I also found it important to get yourself in a good balanced psoition to handle the angle grinder - it hardly needs any force as it just cuts like butter - the main thing is to be well balanced and hold the machine very steady. I think next time I would draw my lines with a Nikko pen as that would be much easier to see/follow than a biro line.
These are the carbide burrs I use with my Ozito (demel type tool)
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Thanks Cruiser.
I should have used tape with marker. Here are photos of todays endevours. Still chasing the leak it could be more than one. So far I've cured 14 in the last four year I've had the boat. Most above deck fittings and seals. Buyer beware of new paint and low price.
As for position. Not too much foot grip under the cockpit in the aft birth. Hot bath and Scotch tonight. Oh it was the hottest day this year hitting 30 C it doesn't get much above 25 C here.
I should have used tape with marker. Here are photos of todays endevours. Still chasing the leak it could be more than one. So far I've cured 14 in the last four year I've had the boat. Most above deck fittings and seals. Buyer beware of new paint and low price.
As for position. Not too much foot grip under the cockpit in the aft birth. Hot bath and Scotch tonight. Oh it was the hottest day this year hitting 30 C it doesn't get much above 25 C here.
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Like your fancy dress Mic - I best add ear muffs to my list even if just to keep the fibreglass dust out of my ears.
I have come to the conclusion that one should just expect to have to re-seal all deck fittings on any boat over a period of time. Every time I have to do any work near any deck fitting I automatically take it right off, inspect fitting and fasteners for corrosion and reseal it. I still have not done my chain plates as yet and from what I have read they account for most of the leakage into the boat. The other thing I will replace eventually is the rubber rubbing strip aroud the gunwhale - never ending list.
Hope you get on top of the leaks soon.
I have come to the conclusion that one should just expect to have to re-seal all deck fittings on any boat over a period of time. Every time I have to do any work near any deck fitting I automatically take it right off, inspect fitting and fasteners for corrosion and reseal it. I still have not done my chain plates as yet and from what I have read they account for most of the leakage into the boat. The other thing I will replace eventually is the rubber rubbing strip aroud the gunwhale - never ending list.
Hope you get on top of the leaks soon.
Touche ----"BEST"--- should have read easiest
Not enough room to use my router on the five holes made under seats made by PO. I will use the Dremel as a router. Thanks for the tip
Ear muffs will do for dust if not sound as I use hearing aids.
The easy way would be a skill saw with a cut off blade and the depth set to just cut the glass and a vaccumn attachment.
You could out the entire floor in about 5 min.
You could out the entire floor in about 5 min.
I've cut a lot of fiberglass and dremel with various cutting tips and wheels is at the top of my list. Sharing the top is an angle grinder with fiberglass cutting wheel. A rotozip worked ok but went through too many tips until I used the angle grinder attachment and worked great. The occellating saw like fein didn't do alas well as I thought. Only for small areas. Works great on teak decks. Forget the jig saw and sawzall - you'll end up with a hole but a messy one most likely. Good luck. Nothing says boat ownership like taking a saw to a fiberglass boat. A dremel also has some nice finishing bits to clean up the edges (or a router).
Use a GOOD asperator and not just a paper mask. Fiberglass dust is like powder and can really irritate skin and lungs.
Don't forget to remove cushions and cover the interior with plastic or on those hot summer nights when your laying on the cushions you'll be reminded of the short cuts you took cutting the glass. If you're cutting through the cabin top use a big box and tape it under the hole so the dust will be caught before flying all over.
I hadn't thought of we towels but I'm going to try it next time.
Good luck
Use a GOOD asperator and not just a paper mask. Fiberglass dust is like powder and can really irritate skin and lungs.
Don't forget to remove cushions and cover the interior with plastic or on those hot summer nights when your laying on the cushions you'll be reminded of the short cuts you took cutting the glass. If you're cutting through the cabin top use a big box and tape it under the hole so the dust will be caught before flying all over.
I hadn't thought of we towels but I'm going to try it next time.
Good luck
late to respond...
a circular saw with a metal wheel (and masking taped fglass) cuts pretty well on long straight lines. (lots of dust).
or a cut off wheel, or a dremmel for smaller cuts.
sawsall and jigsaws tend to not cut clean lines.
-what I really want is the newer 'roto-zip' tool basically a drill and a router combined...
a circular saw with a metal wheel (and masking taped fglass) cuts pretty well on long straight lines. (lots of dust).
or a cut off wheel, or a dremmel for smaller cuts.
sawsall and jigsaws tend to not cut clean lines.
-what I really want is the newer 'roto-zip' tool basically a drill and a router combined...
I've actually had good luck using a jig saw and a very fine toothed blade. I use very little pressure and take my time. The dremel tool sometimes gets away from me and makes an uneven cut. I do keep one of each on my boat for repairs or projects while on the water. Taping the area is essential to keep from scratching the fiberglass. The jig saw usually makes a clean cut and only needs a little cleaning with a file to finish up.
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