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Fiberglass / Structural Strength / Old Town Trapper

Discussion in 'Wood and Canvas' started by jrghaven, Mar 17, 2008.

  1. jrghaven

    jrghaven Enthusiastic about Wooden Canoes

    Hi, first time post here!

    I just acquired a 15' Old Town Trapper (1967) (#177812) for restoration. The hull has a remarkably sound shape, with only 4-5 spots of planking that need to be replaced, plus the outwales. Maybe a deck, although I'm not 100% sure that is necessary - depends on the 'look' I'm going for. Oddly enough, the ribs look fine. I'm going to try and keep as much original wood as possible, as long as it is structurally sound.

    The canoe was originally glassed ("polypropylene covered ADM resin") in natural color. The first person to acquire the boat for restoration has actually stripped most of the glass already.

    My question (first of many I'm sure) regards whether to re-glass. I had purchased the canoe with the goal of canvasing, but I'm really stunned with how brittle the old cedar appears. I can't imagine EVER resting any weight on this - posts I've seen (and comments online) suggest that canvas is very strong, but those are always in reference to rocks, logs, and things below the boat. I'm very, very concerned about breaking from above, the weight of my feet or knees. I don't have a sense whether this brittle quality is inherent to all old cedar canoes, or if this is a unique problem to this boat. The planking looks great, but there just isn't much strength to it. I feel like I could "punch" through or crack it if pressed with inappropriate force. I don't want to restore a boat that isn't sound upon completion.

    SO - in my opinion (and I'm probably jumping to conclusions), my thought is that if I reglass I'd gain an additional layer of support around the entire boat. Oddly enough, because the boat was originally fiberglassed, that would be consistent with a restoration to the boats original form [although it pains me to say that as I had no intention of glassing it]. That, with re-"hydrating" the wood w/ linseed oil, then varnish, might get the boat back to a usable, although heavier, point. Replacing all of the planking is definitely beyond my limited workspace at the moment.

    Any thoughts on whether fiberglass might accomplish what I'm hoping for? I'll post some photos in a few days when I can borrow a digital camera, but unfortunately no demonstrations of how brittle the cedar is! :)
  2. Fitz

    Fitz Wooden Canoes are in the Blood

    Thin planking

    Someone correct me if I am wrong, but a 1960's vintage Trapper model I am working on has very thin 1/8th in. thick planking which I guess was meant to keep the weight down. I needed to replace many planks in the bottom because of this. It may need just need TLC anyway. I can't comment on the fiberglass question.

  3. OP

    jrghaven Enthusiastic about Wooden Canoes

    I think you are right...

    I'll measure the thickness of planking when I remove the first sections, but I think you are right. The boat is ridiculously light at the moment (strikingly so), so perhaps it's also a matter of the thickness of wood used. I think that once it's oiled up a bit the wood will find a bit more softness and flexibility - at the moment it's like a giant, thick, dessicated, potato chip... ;)
  4. Dave Wermuth

    Dave Wermuth Who hid my paddle?


    I will take a stab at this. My '26 HW had been 'glassed at some point. Upon recanvassing I thought the wood to be brittle and I think it is because the 'glass suffocates the wood. the wood can't breathe. It might be helpfull to use some type of penetrating oil to bring it back. My OLd Town is just fine. but I am pretty carefull for the most part.

    Your canoe is going to have thin ribs and planks. so it'll be more delicate anyway but I think it will work out ok once you get it finished.
    Downeastpaddler likes this.
  5. OP

    jrghaven Enthusiastic about Wooden Canoes

    Dry wood...

    Sorry, my spelling is atrocious (desiccated..."...the state of extreme dryness") I think describes it well. I like the idea of an oil that would penetrate the wood unusually well. If anyone has any tips on a good oil for this purpose, I'm up for any ideas. Obviously this will have to sit for a few weeks afterwards before deciding on glass v. canvas, although I like to at least have some plan to make sure things move along.
  6. MikeCav

    MikeCav Restorer/Videographer

    If you plan to replace it with glass, oil might not be a good idea, since it may interfere with adhesion. You may want to strip the varnish first, then glass, then oil the inside of the wood - let dry for a long time, then varnish.
    Last edited: Mar 17, 2008
  7. OP

    jrghaven Enthusiastic about Wooden Canoes


    I like your proposed order of things - it makes sense, plus oiling on the inside alone would be fine.

    Out of curiousity (I've never glassed anything - you can see I'm in for a whole heap of trouble here!), does fiberglass crack at drill/screw sites? As I need to replace the outwales, I originally figured I'd do that after canvasing with little problem. But with fiberglass, will I get shattered little circles around each location of screw attachement? I guess they would be hidden by the rail, so maybe it doesn't matter, but the same goes for the keel which has be a little more worred about keeping the boat water-tight (yes, there was a keel attached w/ holes already in the ribs - I think I'll need to replace that if just for aesthetics).
  8. MikeCav

    MikeCav Restorer/Videographer

    IF you glass - Pre-drill the outwales through the glass just a touch oversize to allow for wood movement - keep the proper pilot hols sixe through the rib and inwale. For the keel, apply a good marine bedding compound to the concave on the keel and dip the screws in it before fastening. Should be fine.
  9. Todd Bradshaw

    Todd Bradshaw Sailmaker

    Fiberglass would add strength in terms of forces applied from inside (like walking around) because the glass would be in tension, which it does pretty well. It would, however do very little strength-wise when force is applied from the outside (like hitting something) as the glass is in compression - which it does not do well. It would add some pretty decent abrasion resistance though. I'm pretty sure that the OT "Lightweight" (canvas), Trapper (glass) and Featherweight (Dacron) were all built on the same wooden hull, so it should be strong enough with any covering but it was made to be light at the expense of some strength and that's not going to change much with the various coverings.

    To do it properly, glassing a wood/canvas canoe is a very tricky first-time project and substantially more difficult than canvasing or fiberglassing a strip canoe. Every tack head depression and every crack between planks has to be filled with something before glassing. Otherwise, the resin runs through and leaves saturated cloth, but something very similar to screen wire bridging those spots. Tack head depressions can be filled with an epoxy filler mixture and sanded flush. Plank gaps can be filled with the same or possibly something temporary (tape, clay, maybe even plaster or drywall mud to be washed out later). You just don't want the screen-wire spots as they are a real ***** to fill and fix. If you plan on glassing, don't get oil anywhere near the surface. You want it as dry as possible and free of any kind of contaminants. You can run screws right into normally-drilled holes for gunwales without worrying about cracking.

    I really believe your chances are much better with canvas than fiberglass. I personally hate linseed oil and would put pig spit on my boat before I'd ever get near it with linseed. All too often it turns black and studies by the Forest Products Lab have shown that it's great food for rot spores and a lousy way to preserve wood. Before canvasing, I'd get the boat stripped, sanded smooth and clean and then oil and hopefully re-moisten the wood with multiple coats of Deks Olje #1, inside and out. It's a synthetic boat oil finish that soaks in better, dries in a day or two, doesn't turn black with age and isn't rot-food.

    The fiberglass route works if you're very good with epoxy and glass, but it ain't easy. This is one and if I had to do it again, it would be canvas.

    Attached Files:

  10. bob goeckel

    bob goeckel Wooden Canoe Maniac

    another idea! alot of restorers of wood boats use a product called "Smith's cpes (clear penetrating epoxy sealer) to renew old wood and seal it permanently. i've used it a number of times and it's a great product. it's not rigid but has some flexability. i have not used it on a canoe though. but i would if needed.
  11. Todd Bradshaw

    Todd Bradshaw Sailmaker

    Don't even get me started on that stuff......
  12. chris pearson

    chris pearson Michigan Canoe Nut

    what color?

    Todd, what color is that? Is it a Kirby color? I like it!
  13. OP

    jrghaven Enthusiastic about Wooden Canoes


    This is going to be a tough decision - as I've been going over the hull removing any remaining small pieces of fiberglass/epoxy still left, I'd noticed that the nail holes and gaps were filled with a white/tan filler. Now that makes sense given the need to fill these before glassing.

    I guess I'm going to give this some thought (i.e., remain indecisive until the weather improves a bit) - it's going to take a least a few weeks to a month to get the few planks replaced and everything stripped and sanded. I still need to price out wood for the outwales and keel - I can see why this hobby is so engaging. My smarter sense tells me to resell it on Ebay and buy a small puzzle if I'm in for such a painful challenge - but I think the reward of finishing it (and the paddling it) is well worth the indecision...
  14. Todd Bradshaw

    Todd Bradshaw Sailmaker

    It's just a pale yellow porch and floor enamel that I had mixed up at Ace Hardware. I've never really been a huge yellow canoe fan, but on a wooden boat the color contrast really brings out the rosy tones in the cedar. Goes nicely with Mother Nature, too!

    Attached Files:

  15. john hupfield

    john hupfield fire starter/wood burner

    Me I would not mix fibreglass and oil at all.Cetainly I don't think epoxy sealer is your best choice either.I'm curious about Pigspit a unknown Bradshaw product that maybe is good for polishing boots,but of course is unknown.
    Canvas gives you all of the traditional options that work for 20 or 30 years without the joys of fibreglass.Both routes have a learning curve.
    Boiled Linseed is OK if you warm it and cut it with turps.Most boiled linseed brands have mildew inhibitors and only turn dark on exposure to air.Thus a varnishing afterwards.Most old formula canvas fillers used linseed oil as a base.Usually it soaks in so fast you don't think you added anything.A couple of coats is preferable to brittle cedar which has leached out all of its natural oils.
    I was thinking of glassing my piano but really need a formula for...
    How's the weather Todd?
  16. Todd Bradshaw

    Todd Bradshaw Sailmaker

    Hi John, the weather is improving and snow is starting to melt, though we're not usually done with winter quite this early. Pig spit is great stuff, but the collection process is rather tricky. One must squeeze the pig just right to get the proper stuff to come out the proper end as the other options are not pretty.

    We used to record at a studio where they had put shellac on the felt hammers of their piano to brighten the tone up (you can always tone it down on the control board, but you can't tone it up if the sound's not there to be had). I suspect a good layer or two of fiberglass on the hammers would be almost as good as using thumb tacks for that antique, silent pictures sound. As for the sound board, it would hold up well if you hit any rocks while playing, but the glass might tend to dull the tone a bit.
  17. OP

    jrghaven Enthusiastic about Wooden Canoes

    Oil and Fiberglass

    The prevailing opinion (if I've summed things up correctly) was:

    1) Better to canvas, but if I do fiberglass
    2) Don't mix oiled wood and epoxy (won't stick), so
    3) Fiberglass exterior first, THEN oil the inside to replenish the wood

    BUT - my question is whether the wood would expand once oil is applied? Would following step 3) cause the fiberglass to crack? Or does wood not expand when oiled as it does when it soaks in water...

    If I treated the interior wood, THEN fiberglassed, oil or whatever treatment will certainly drip through some of the cracks and space between planks.

    Because someone will certainly ask, I'm really just not confident that the wood is strong enough to withstand the weight of passengers in the boat if I canvas it. I could oil/treat the heck out of it, internally and externally, which -might- do it, but then I can't fiberglass the boat anymore - hence the reason why I'm still leaning toward glassing. It's also "restoration appropriate" - given the history of the boat stated in earlier postings.
  18. Todd Bradshaw

    Todd Bradshaw Sailmaker

    I doubt you would notice any serious expansion from oiling the inside. First of all, oil doesn't soak in anywhere near as far as most folks think it does (neither does diluted varnish, diluted epoxy sealer, etc.) If you want to prove it to yourself, oil a hunk of scrap wood, let it dry and then take a sander to it. Before long, you will be right down to bare wood with no sign of oil. The face of a cedar plank or rib is a very different from those little bits of end-grain showing between the gunwales. It will never "drink-in" multiple coats of finish at a similar rate to it's end-grain. Cedar also does not have the open pores on it's surface the way some woods like certain mahoganies and oaks will. This is good - otherwise we would probably have to mess with grain-fillers in order to get a nice smooth varnished finish on our canoes.

    Once the epoxy coat has locked onto the wood and cured I have never seen any evidence of oil finishes lifting, attacking or otherwise affecting it. The wood that is epoxy coated is quite stable. We see this on such things as laminated sailboat tillers, glued with epoxy and then oil-finished or glued lapstrake dinghies where the plank laps are glued with epoxy and oil finishes are common for interiors. In any case, you want to wait until your epoxy is applied and well cured before getting oil anywhere near the boat.

    The other contributing factor is thickness. Epoxy/fiberglass is capable of "out-muscling" wood that wants to expand as long as the wood isn't too thick. There are limits though. If you slap a layer or two of epoxy/fiberglass on a 1" thick plank and the wood expands, it will probably fracture the glass. Therefore, most composite/wood/epoxy boat technology employs thin layers of wood, stabilized by the resin and often fiberglass fabric. A typical layer or two of 6 oz. fiberglass generally does not have much trouble stabilizing something thin like the planking used for wood/canvas-type canoes or the strips used on stripper canoes. The same can't usually be said for a similar application of glass on a big old wooden sailboat with 3/4" thick planks.

    Keep in mind that oil finishes are lovely, but you do need to actively maintain and renew them. Otherwise they tend to let dirt and water into the wood, which is seldom good for it. If it looks like your finish needs renewing you don't want to delay it.
  19. OP

    jrghaven Enthusiastic about Wooden Canoes


    Thanks Todd, your reply is very much appreciated!
  20. Andre Cloutier

    Andre Cloutier Firestarter. Wicked Firestarter.

    the solution

    Since everyone flinches when you fiberglass a wood canoe (rightly so IMHO),
    hit it with every petroleum and porcine or bovine based product you can, then glass it. That way you have the durability of fiberglass, and the convenience of lifting the canoe clear of it anytime you need to perform maintenance or repairs. Just like so many old cedar strip outboards that had the bottom glassed when polyester resin was the new hot ticket.

    Okay, sorry, havent had a lot of sleep in the last 48 hours.

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