Fiberglass / Structural Strength / Old Town Trapper

Todd Bradshaw

You do realize, of course, that all that weathering and staining on the outside of the hull isn't going to go away when you clear-finish it with fiberglass. The resin will actually accentuate the differences and make the contrast between clean wood and weathered or stained wood even more obvious. The planking on those is too thin to tolerate much sanding (especially if you concentrate on trying to clean up the inside) and you don't really want to sand into the tack heads. Much of what made the Trappers attractive was that the planks were carefully selected for uniform color and it was all fresh, clean cedar when the skin was applied. As for rocky creeks, fiberglass is somewhat more scratch resistant than filled canvas, but by no means abrasion-proof or impact-proof. This brings up the question of which is more durable - a boat with a moderately tougher skin but one where it is extremely difficult to repair or replace any cracked ribs or planks from rock impacts, or one where the skin is a bit softer, but any part on the entire canoe can be replaced over the years?

With the combination of the questionable cosmetics of the old wood and the mention of use in rocky streams, I'd save the glass to make a stripper sometime. I'd cover this one with canvas instead - and spend my energy trying to get the interior wood looking good again, because you don't have enough plank thickness there to clean up both sides for a good looking clear-finish.


Curious about Wooden Canoes
:) Can you recommend a place that sells canvas. Should it be done with light weight, standard or heavy? Untreated or mildew resistant? I found North woods Canoe.. but I am on a tight budget and would like to weigh out the cost differences of the the Canv./filler/paint vs. fiber./resin epoxy.
I know in a long run canvas is the way to go... but right now the budget might or might not allow..?
Thanks again.

Dan Miller

cranky canoeist
Staff member
If this particular canoe were my canoe, this is what I would do:

Cover it with No. 12 canvas. This is not available in a treated form, as far as I know. Northwoods is one of several that can supply canvas - others are listed in the WCHA Builders and Suppliers Directory. Some tent and awning firms stock no. 12 canvas if you want to look locally.

For filler, pre-mixed is available again from several WCHA builders. I mix my own using the first Old Town recipe listed in the Knowledgebase:

Alternatively, I also use the waterbase Ekofill filler also described in the KnowledgeBase (last entry).

Since the canvas is not treated, I would treat it with a *paintable* wood preservative prior to filling, and add mildicide to my filler.

Finally, paint with a good quality marine enamel.


Wooden Canoes are in the Blood

I have used the Jasco stuff and found it to work pretty well, even in cold weather. Use the search function here on the forum to look for information on stripping varnish. I typically apply the stuff to a small section of the hull, let it work for about 1/2 an hour or more, and scrape gently. Not much comes off with the first application. Then I re-apply to the first section and start a second section while the first section is working. I repeat and leap frog down the hull. As I mentioned, not much comes off in the first pass over each section, but if you keep everything wet with stripper the remaining passes are much easier and will give you renewed confidence!! You will likely use almost 2 gallons of stripper. Have plenty of tools available....gentle use of a putty knife so as not to scratch the wood, plastic brillo, and plastic brushes, tooth brushes all work well. Use all available safety clothing and gear you can find. It is a nasty job.

Good luck.



Curious about Wooden Canoes
Thanks Fitz.. yea the can says best use 65 and up.. I will give it a another try once it warms up a little around here and then try your method.


Curious about Wooden Canoes
Dan, Northwoods has that #12 (lightweight) treated for $5.50 a foot. If i were to go with canvas. I would like to go lightweight. It just makes me wonder with the wood planking being so thin?? Could it be #12 or should i go to #10 (standard)?
I'm just saying if I go with canvas!:) still looking it over..


Builder & Restorer
If this canoe were my canoe, I would Glass it. It was glassed originally from the factory and was built to be glassed. In looking at your Pictures it appears to have tight planking and very few gaps to worry about. If you glass it do it right. Two layers of Min. 6 oz Applied one at a time with a good epoxy. ( I like west system ) Put at least 2 filler coats to completely fill the weave of the glass and have some to sand. Glassing the bottom of this canoe is just like building A laminated beam!!! It will give you more strength than canvas. As far as replacing broken ribs planks or anything down the road you can still do it without stripping the glass. A good glass job is life time in my opinion.
Now if this was A classic canvassed canoe to start with I would be urging you to re canvas it.
All though I ones took a restorable 1923 model T and put a 327 small block in it

Todd Bradshaw

There are a whole bunch of things which are wrong with that statement. The construction has the same basic scantlings as an OT Lightweight (canvas-covered) or Featherweight (Dacron-covered) and it would be fine with any of the coverings. A single layer of six-ounce with a second layer over the bottom 3" or so is plenty if you glass it. You actually get a higher glass-to-resin ratio (more strength per ounce and less overall weight) if you apply and saturate both layers at once. Glassing the outside and inside of a stripper is like laminating a beam. Glassing the outside of a rib and plank canoe, not so much, and the "strength" gain is minimal at best because the average stress on an outer skin does not put the fiberglass in tension - which is what fiberglass does best. You can expect a possible increase in abrasion resistance over canvas (but not an awful lot) but the canoe will not have "more strength" than a canvas-covered one. The stuff simply doesn't work that way. There is no question that major repairs are substantially easier with the canvas removed and without everything being glued together with epoxy and fiberglass.


Builder & Restorer
WOW Your a better man then I . Its difficult enough to get one layer of cloth smooth and filled without bubbles or wrinkles. Wetting 2 at a time isn't worth the hassles to me. I didn't say the canoe wouldn't be fine with canvas I said I would rather see it glassed for the reasons Tex has already said about how he wants to use it. In my experience working with glass it will make a substantial difference in the strength of the hull. Yes it's allot easier to do repairs on a canoe with the canvas removed, But for every .10 repair job you got to add $1,000. to re canvas.

Living where I do and working on Canoes for a living you need to learn how to deal with Fiberglass. I am willing to bet that within 20 miles of my shop there are 300 Grand Lakers and 290 of them are Fiberglassed . The few that are still canvas are someone's Grandfathers that has been hanging from the rafters for the last 40 years.


Living where I do and working on Canoes for a living you need to learn how to deal with Fiberglass. I am willing to bet that within 20 miles of my shop there are 300 Grand Lakers and 290 of them are Fiberglassed . The few that are still canvas are someone's Grandfathers that has been hanging from the rafters for the last 40 years.

Ohhh boy, the next day it rained.

I think the Grand Laker and the wooden canoe have different purposes. From my experience folks that use the Grand Laker are filling it to the rails with coolers, sports and their gear that get hauled to a site and then unloaded.
A typical canoe will carry a couple back packs and paddlers.
The Grand Laker will get loaded on a trailer and hauled from one river system to another while the canoe will probably be paddled and carried.
Folks up your way that use canoes similarly to Grand Laker usually have a 20 foot OT rubber guide mounted with an outboard.
Those get rammed around the way the Grand Lakers do.

This thread is about a paddling canoe, not a working boat....fiberglass really does not (should not) enter into the picture unless you consider using it the way that the Grand Lakers are used,. Fiberglass on a Grand Laker is for hull stiffness and abrasion resistance and to eliminate annual maintenance whereas a canvas on a canoe offers hull flexibility (and keeping to the Maine canoe style) a degree slipperiness on rocks from the combination of canvas, filler and shellac. It's not a battering ram.

Comparing these boat types is a bit like comparing apples and pineapples.
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Todd Bradshaw

There is nothing particularly difficult about installing two layers of fiberglass cloth at once. It is simply a matter of taking your time and attention to detail. The first thing to do is to get an assistant. That person's only job is to mix a steady stream of small batches of resin while you do the application. That way you aren't rushing to mix batches while trying to apply the stuff and can concentrate on the job. You're also a lot less likely to accidentally mis-mix a batch due to rushing to get back to applying resin. Cloth takes time to absorb resin and the fresher that resin batch is, the better it will absorb, so you want to work with small-ish batches, starting in the middle and working out in both directions or from one end, working toward the other end. Some people do the spreading with a squeegee, I prefer a foam roller, but both will work and you want to use moderate pressure with either one. Too much pressure tends to cause the resin to foam and can trap a lot of tiny air bubbles down in the cloth. Structurally, they're no big deal, but on a clear finish they can show. On a surface that will not get filler coats (like the inside of a stripper) I'll generally go over it after rolling with a foam squeegee. These are just slabs of ethafoam cut about 1/2" thick on the band saw or with a fillet knife. They will allow you to "comb-out" the final cloth texture to a very uniform pattern that's tightly down on the surface, free of excess resin and pretty decent looking despite showing cloth texture.

Bubbles and/or wrinkles are usually caused by the cloth moving a bit as you saturate it. With either a roller or a squeegee you have the ability to create tension, pulling the cloth away from the wood and making a bubble, or by pushing the wet cloth and piling it up, forming a wrinkle. Again, working with small, fresh batches of resin will give you maximum time to address these problems and fix them by moving cloth toward the bubble or away from the wrinkle to spread it back out and get it down tight to the wood where it is supposed to be. Before you leave one small area to work on the next, be sure it is the way you want to leave it, as going back later when the area has started to cure is usually just going to make things worse. It is also a good idea after laying the cloth dry on the hull before you start saturating it to go along with a pair of scissors and trim off the factory woven selvedge edges from the cloth. This will free up the weave a bit, which allows the yarns to move on themselves more and the cloth to conform to rounded shapes better and with fewer stubborn spots, bubbles and wrinkles. If you are doing an additional half-layer over the bottom, you lay that layer on first, then the full layer over it and saturate both at once. That way the resin will go a long way toward filling and fairing the "stair-step" where the hull transitions from one layer to two (fewer filler coats and less sanding will be needed to smooth the transition). It also uses less resin, gives a higher glass and strength-to-resin ratio and adds less excess resin weight to the hull. You don't need to be some sort of fiberglassing wizard to do this. It's just not that difficult if you work carefully, and it can be done on glass as heavy as ten ounces or more on big boats with a bit of care. Double-glass up the sides of a canoe really isn't needed and usually just adds cost and weight. That glass just needs to keep water out unless you're in the habit of hitting things which are well above the waterline. Since outside sheathing adds so little impact strength to the structure, heavy glass up there isn't really going to strengthen the hull much anyway.

Your notion that fiberglass skinned canoes are "stronger" than canvas skinned canoes simply is not true. Fiberglass yarns do have higher tensile strength than canvas yarns. This means that when you grab one and pull on both ends, it will have a higher breaking strength than the canvas yarn. It will also have less elongation (stretch) before it breaks. However, the typical rock impact does not take advantage of the tensile strength of a fiberglass outer skin. Two layers of six ounce cloth makes a skin that is just about as thin and flexible as a plastic milk jug. If you don't believe that, lay up a couple layers on a sheet of waxed paper, let it cure, peel it off and flex it. When a canoe impacts a rock, the hull flexes inward. The outer glass skin bends a little bit, which is no problem (as shown by flexing your test sample or milk jug). It's hardly being stressed at all. The real stress from the impact is on the inside of the hull. The thicker the core or structure and the farther you get from the rock, the more tension and stress there is on the inside of the hull. It will stretch or flex from this tension to a point, and then it will break - long before the outer skin has even been damaged.

In the case of a rib and plank hull, the wooden structure will break long before the glass has even been damaged, and the glass layers are not able to add any significant strength to the wood because they're not being put in tension, which is where their true strength lies. They're just flexing a bit. The strength (and the limits of impact strength) of the wooden canoe is the wood inside, not the outer skin. Whether it's fiberglass, canvas, Dacron, Kevlar or polyurethane saturated monkey fur, it simply is not in a position where it can make a significant tensile strength contribution to the structure on impact. In order to fiberglass the outside of a wooden canoe hull and get a significant increase in impact strength you would need to add almost as much fiberglass as it takes to build a stand-alone fiberglass canoe - and who wants a 15' canoe that weighs 120 lbs.????

If you look through the old Old Town catalogs you will notice that the Trapper was never advertised as being stronger than the Lightweight (same basic hull but canvas covered) or Featherweight (same hull, Dacron covered) models. It was advertised as being "somewhat tougher" on shallow, rocky streams because the fiberglass is somewhat more abrasion resistant than filled canvas, but it was never claimed to be a stronger structure because it is not. Despite the higher tensile strength of fiberglass, in this type of construction if you have the same wood on the inside where the real brunt of an impact will be absorbed (or not - resulting in a break) you will have similar strength. In the case of the OT Trapper, the strength will be that which you can generate with 1/8" thick cedar planking and 1/4" thick cedar ribs.

Much of this will also apply to wood strip/fiberglass boats. It's the same deal only in this case, the outer glass will flex a bit, as before, and the real tension from the impact is borne by the fiberglass inner layers. The thicker the strip core, the more tension those inner layers will get. The good news is that since tension is what fiberglass does best, these layers are in a perfect position to help strengthen the boat. The bad news is that even so, rocks have more strength, so a stripper is by no means unbreakable. One of the most common rookie-strip-builder mistakes is to skimp on the weight of the inner glass. They think "Gee, the rocks hit the outside, so I'll save a few pounds by reducing the weight of the inner glass layers."

"Hey buddy, you may have saved five pounds, but in the process you just gave away half of the impact strength of your canoe, because those inner layers were its main contributor."

The big canoe has two layers, 22' long of 10 oz. fiberglass over the bottom, inside and out, applied at once as stated above. No bubbles, no wrinkles. The drift boat has two layers of 7.5 oz. glass over the bottom, inside and out, applied at once. The Old Town has two layers of six-ounce over the bottom, applied at once.


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Curious about Wooden Canoes
You both have Great advise and strong points. I am looking for a canoe to use. What with the amount of fish and paddling I wanna do, I wanna have one boat thats very versatile.. I love the idea of the canvas. The look, flexibility and quietness that it offers. But I've been watching videos of Canoe/camping/fishing trips (on the internet) up and down streams, lakes and more. I notice those canoes are some sort of plastic, kevlar or fiberglass.. never canvas... That said I picked up some books at the library today (The wood & Canvas Canoe, The art of the Canoe Joe Seliga and The maine guide Canoe)... So thanks for all the help but those beautiful books mixed with both of your obvious experienced points have only helped to strengthen my indecision. ;) But hey! There are bigger issues in the world! Right? At any rate it's still cold here. Hudson Valley NY. so I have plenty of time to ponder. Thank a billion guys. Tex


Curious about Wooden Canoes
Hey guys.. If I do glass it. How long is it going to be before it gets all scratched up milky and rough looking? I don't plan on beating the hell out of it! I actually will be storing it indoors and taking care.. but how long will it be "nice" from normal use? And say in a few years I wanna bring back that clarity of the wood.. Is it sanding? and new varnish? or maybe anther light layer of resin? I know to fill the weave plenty to have room for sanding down the road and all.? but its also a factor I'm bouncing around in my head. Thanks


Unrepentant Canoeist
For my cedar strip canoe, usually every time I put it in the lake, it gets some light scratches. I don't take it on rivers any more -- got tired of fixing it.

These are just light scratches from shoreline gravel & sand, & just need a light sanding & varnish. But lakes can have rocks, logs, etc to run over, too... All of my launchings & landings with this boat are "wet foot," but it still gets scratches. Make sure the hull is free of all grit before putting the tie-down ropes or straps on it. I used to wade it out into the water & wipe it down, but I still got scratches. At some point, you just live with it.

If you want to keep it looking pretty, plan on at least once a year, depending on how meticulous you want to be.

Greg Nolan

“But I've been watching videos of Canoe/camping/fishing trips (on the internet) up and down streams, lakes and more. I notice those canoes are some sort of plastic, kevlar or fiberglass . . . never canvas . . . “

Tex --

There are a couple of reasons why you don't see many videos of wood/canvas canoes --

there simply are vastly more plastic and composite boats now in existence, largely because they are usually cheaper than wood/canvas canoes, and --

you may not have been looking in the right place. Check out "Places to Paddle" in the "General Topics" section of these forums, where there are lots of photos (and a stray video or two) of wood and canvas canoes in use; here is a video and a thread with good pictures of a camping trip from that thread, and some youtube videos:
video of Big East River Poling and Paddling
pictures of a camping trip, with a link to even more pictures of a more ambitions trip:
some pictures of a camping trip in the Adirondacks
has a link to pictures of a week-long venture into Quetico
pictures of Alligator Lake, Florida
pictures, mud lake portage on Allagash trip
The New Hampshire Chronical video of the 2010 Assembly

Here are some youtube videos featuring wooden canoes:
The New Hampshire Chronical video of the 2010 Assembly
slightly (?) crazy people in a birchbark
canoes at the 2011 WCHA Assembly
you tube demonstration of paddle stroke
Becky Mason paddling birchbarks made by Steve Cayard and Ferdy Goode
Canoe from the 1890’s

Todd Bradshaw

Very shallow scratches can be varnished over and will at least visually disappear. Deeper scratches in the filler coats can be filled with resin, sanded smooth and varnished and will also look pretty good. Deep scratches down through the filler coats and into the cloth will be white with visible cloth texture. Even when filled, they don't ever go away. The only way to remove them is to cut out that part of the cloth, re-glass those spots and try to fair and blend it in without creating a lump. If your resin gets milky looking, it is most likely damage from UV and you are basically screwed. Epoxy resin will start to deteriorate with as little as 200 hours of direct exposure to sunlight unless covered with a high-quality UV resistant varnish. Even so, the UV absorbers wear out as they do their work and a clear finish should probably get a light sanding and a couple fresh coats of varnish every three or four years to maintain protection. If you let it go until it's cloudy, about all you can do is sand off or otherwise remove the resin and glass and start over. In the process, you will find that epoxy resin and fiberglass is much harder to remove than the polyester resin fiberglass that was originally on the boat. At that point, you might as well just make bookshelves out of the canoe. So, how long a clear finish will look good will depend on how careful you are to avoid deep scratches and how well you maintain your UV protection. Paint, by the way, is the best UV blocker you can buy. It may chalk at the surface and slowly wear away from UV, but it lasts many times longer than varnish and the UV can't penetrate beneath the surface.

It is, however, reality check time. In its current condition (and for the remainder of its useful life, no matter how hard you try or what you do to it) this canoe is a lousy candidate for a nice looking clear finish. Unless your idea of "nice wood" is gray, weathered wood with black and a few (very few) remaining tan blotches, this thing is going to look like a real hack job under a clear finish. Clear finishing needs to be done on brand new clean wood, without water damage spots, heavy weathering and tarnished tack heads with stained wood around them. Those models have such thin planking that doing any sanding on the outside is pretty risky to start with, and by the time you even got close to the look of clean cedar, half your plank thickness and most of the tack heads would be sanded away. The first time you put it in the water and stepped in, the planks would start splitting. The outside of the hull looks pretty bad already and fiberglass doesn't fix that - it makes it look worse. It will make the colors darker and accentuate the blotchy look big time.

I know you really have your mind set on the clear finish, but this one is never going to look like an original Old Town Trapper again, it is simply too far gone. You have enough plank thickness to do a reasonable amount of clean-up and revarnish the interior, so you'll have some nice wood to look at, but not enough to do both sides. You can either canvas it or glass it and paint the outside to look quite respectable, but it is simply never going to look like anything but a beat up, weathered old canoe that somebody should have fixed properly with a clear outer finish.


Curious about Wooden Canoes
I don't care how blotchy or off color the wood looks to me. In my opinion that will only ads to it. The rugged look. That said I still might canvas only because I'm thinking I will be happier I did in the long run. I was looking at Northwoods #12 mildew resistant or #10 standard? I would like to go lighter. Just wondering if it's a good Idea with the thin planking... And what do ya'll think of there filler? How much would it take? A gallon? I'm not to confident in mixing my own. Thanks again guys for all the help and Greg for those great videos.


Curious about Wooden Canoes
Comply, Comply, Comply.


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Curious about Wooden Canoes
She's a good girl... I can't trust her judgment though... she love me too much... or she likes to eat:)
One question.. though... I wanna go ahead and fill the canvas but it's so humid and will remain for a few days.
Does Humidity have a big effect on results??