fiberglass removal?


"Tiger Rag" back on the tidal Potomac
In Memoriam
Old Town 127140 is not in terrible shape. It will take 3 or 4 replacement ribs and one square foot of new planking prior to canvas and paint. But before anything can be done I've got to get the fiberglass off. I know this has been discussed before, and I've read those posts. What I have is about the worst possible situation: examining a damaged area, what I think I see is that the canvas was removed and then two layers of glass with a huge excess of resin applied. The boat weighs over 100 lbs. Trying to get a piece of glass off, too much planking wood is attached. So my plan to to submerge the canoe. I've removed the outwales, two thwarts, portaging yoke and seats.

So rather than repeat mistakes others already know of and ideas that will not work, a few questions :
How long should I submerge the canoe? One week? Two?
Would it help get the glass off in strips if I cut a series of slits, 1/8 inch deep, maybe 3 inches in-between, through the glass?
After water has had a chance to penetrate and hopefully loosen the resin bond to the planking, would it do any good to use a heat gun to generate steam between glass and wood?
Thanks for the tips. Tom McCloud
I'm no expert, and will defer to other opinions, but I've been doing well with just the heat gun and putty knife -- no submersion involved. Patience is crucial... don't pull off what isn't ready to be pulled off. Once the goo is hot, the glass cloth will lift (slowly, gently) pretty easily, and will leave the wood intact. Use the putty knife sparingly; don't force it under the cloth too much...

Then scrape the softened resin off before it hardens, and keep going. Once all the glass is out of the way, the sanding starts. :(
There really isn't much reason to suspect that water will delaminate the fiberglass. If you truly saturated the wood with water, causing it to expand, you might get a little bit of shear breaking the bond in places, but most likely not enough to be able to grab a hunk of glass and peel it off without taking a lot of plank wood with it. Fiberglass, even badly applied fiberglass, is substantially less fragile and a heck of a lot more waterproof and resistant to change or damage from immersion than cedar is.

Heat is the way to go. In order to get the fiberglass off, you have to do something that softens it and reduces it's bond strength until it is below the grain strength of the cedar planking. This is what will allow you to peel it off without taking wood with it. Since soaking really doesn't change the nature of the resin, it can't be counted on to do this evenly and consistently and the result will be wood being torn off the boat anywhere that the bond is still good. How good that bond is will be the luck of the draw. If it's old polyester resin, many of them don't stick very well to wood and the job may be fairly easy (in a nasty, messy sort of way). Other polyesters and most epoxy resins stick much better to wood and the job may go slower, but heat is still the best way to remove them.
In my shop I remove fiberglass from a lot of boats each year. Some people use a heat gun I have found a propane torch and a good scraper the best. Just watch the flame so you don't burn the wood.
How flammable is the softened resin? Is that something else to watch out for, or is it not an issue?

Seems that would work faster than the heat gun? For us less-than-patient types. :rolleyes:
It will certainly burn, but once it's been hardened for a while I don't think it would exhibit any sort of rapid combustion like solvents would. Chances are it's more like wood or other solids. If you hold a torch to it long enough, it will most likely catch fire. Mind you, I've never tried to burn down a fiberglass canoe (though a few good candidates come to mind) so I would approach the problem with both caution and a bucket of water.

The fumes generated by burning paint and resin are almost certainly quite bad for you, so proper precautions there are just common sense.
soak/no soak etc

I have soaked for a week. It provides some moisture so the canoe doesn't catch fire so quick. I think it also makes the wood less brittle and prone to fragmentation. It may also provide some moisture/steam when heat is applied to get things to come loose but, I do not think soaking is necessary. I have also, like Gary, used the propane. you have to be careful and keep putting out little fires. And the burning resin is not something one should sniff. I like the idea of heat gun and methodical use of putty knife. Check out the youtube of Denis removing glass. I think that's the best way. Scoring the glass is done but risky too. you could cut too deep.
I don't know about soaking the canoe as I have never done it. I must have a cheap heat gun because it works no way near as fast as a torch . Yes you must keep it moving and I have never had one catch fire. In my shop I do a lot of work on the guides boats and every day I have there boat cost them money so speed is important to me.
The heat gun I have certainly gets hot enough as seem in the u tube video that Kathy made. There were a couple times it ignited the resin.:(
update on fiberglass removal

An update: based on responses to my inquiry about fiberglass removal, I went at it last weekend with putty knife, chisels, hatchet and heat gun. Some things I was right about. There were two layers of glass. The underneath was woven, the outer was glass mat. There was not good adherence of the first layer to the cedar planking. The strange thing was the bright yellow material coating the inside layer of glass which seemed to be rubbery, like it was a liquid vinyl that was painted on. Sometimes I could get the outer layer started pealing and separate off a long strip from the underneath layer, which then made getting off the underneath layer easier. I used a rotozip with a ceramic cutting blade to cut grooves through the glass. This created weak places and allowed strips to be pealed off with aid of chisel and heat gun. There was minimal loss of planking wood, though some previously hidden damage was uncovered. All told about 6 hrs work on two days at 35 - 45 degrees. Actually seemed to come off easier on the colder day. So all told, the glass removal was easier than I had expected. Tom McCloud
photos of fiberglass removal

Still don't have this photo attachment business down. Second try.


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It seems a shame to have to change this beautiful colour scheme, but the fibreglass has to come off this recently acquired gem, I'm looking forward to the challange. I'll be buying a new heat gun for the task, are there any recommendations? The heat gun I have looks like the one Denis uses in the video, but sounds like it will self destruct soon.

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What a color!! Someone must have done a messy job.

I've removed fiberglass on several canoes and use a plain old heat gun that I picked up at a hardware store. Mine has two settings the largest being 1000 degrees or so it says. I use the high setting just being careful to keep it moving back and forth over a small piece at a tiime and it works just fine. Just a slow process with the putty knife lifting a piece and peeling carefully. Finished one a couple of months ago that had 3 layers of glass along the keel. I just peeling off the first layer and then the others.

Good luck.
fiberglass removal

The heatgun I used was made by Master Appliance, Racine, Wisc., model HG751B, 120 v., 14.5 amp, temp range 750-1000F. That seemed to deliver sufficient heat. I saw discoloring of the glass as it got hot, some bubbling, and a little smoke, but no fires. Got to keep it moving! This is a job that you really need three hands to do, one for the heatgun, another for the chisel, and one for the hammer. l watched that video with Denis removing glass before I started. In the video the glass looked pretty 'rubbery'. My job wasn't like that. The glass stayed pretty stiff, but did peal off with heat and persuasion. Tom McCloud
On that Morris the glass came off fairly easily and as you said it came in longer strips. I would run the gun ahead some to pre-heat it then go back and heat the area I wanted to work.
The Penn Yan I have started is much more tightly secured. It took me eight hours to remove it from just one half and I still have to go back and remove resin. Good luck and take your time. :D