How long will a re-canvas job last?

[Easternrivers]

I recently talked to an experienced canoe builder (same one as my thread on narrow stems) who told me he refuses to canvas anymore canoes since he can't get white lead for his filler. He says the canvas will not last very long, maybe a very few years(3-4) before rot-mildew takes it.
He has fiberglasses his boats for many years now and suggested I do the same with my restorations.
That was disappointing, especially concerning my pre-fire 'Nut. I can't put glass on that canoe...I just can't!

How long does a canvas last with currently used oil-based filler? Or is there a better solution??

 

[chris pearson]

Poo, poo on that. But.... it depends how hard you use it. Most canvas made now comes with mildicide already in it, but ask before buying. If you store the canoe indoors(garage, etc.), the canvas will last a long, long time. Take care of it, and not run rapids everyday or drag it across portages, you probably won't have to recanvas it in your lifetime. Canvas is better than it was 80 years ago!

 

[Benson Gray]

How long does a canvas last with currently used oil-based filler? Or is there a better solution??

The typical rule of thumb is that a canoe canvas will usually last twenty to thirty years in normal use which is probably longer than most of us will be actively paddling as Chris pointed out. Old Town stopped using lead in their filler during the 1960s and plenty of those canvases have lasted much longer than a few years. You can still find small amounts of red and white lead from specialty suppliers but it often is very expensive. There has been some discussion here recently at http://forums.wcha.org/showthread.php?8425 about epoxy based fillers but this does not appear to be universally considered a better solution. My canoes with new canvas have silica based fillers and I have one from 1919 that may have the original canvas. I would suggest that you put canvas on yours and enjoy it.

Benson

 

[Easternrivers]

Well, up here in Canada, as far as I know, lead based products are banned. and hard or impossible to find anymore.
Even if I could find it, shipping would likely NOT be allowed. My guess.

I wondered about this guy's comments as I'm sure that Rollin and others still use some type of filler to canvas canoes, so maybe I'm fretting for no reason. Canvas and be happy!

 

[davelanthier]

To prevent rot and mildew use the liquid " Clear Wood " preservative available , for example, at Home Depot. This is applied to the canvas after the canvas has been installed on the canoe and before any filler. Allow to dry overnight before the canvas filler is used. As an added bonus this solution will also shrink the canvas. Take care as it is very toxic.

 

[Mark Adams]

I don't know if they still carry it, but you used to be able to get white lead from Kirby Paints. I have a 5 pound can of it in the garage.

 

[Easternrivers]

I don't know if they still carry it, but you used to be able to get white lead from Kirby Paints. I have a 5 pound can of it in the garage.

Well it's still on the website...thanks for that idea. Although I may forgo the toxic lead route and use silica or oil based filler instead.
Thanks for all the helpFolks.

 

[Larry Westlake]

A better solution?

Or is there a better solution??

I'm trying to "green up" my boatbuilding, and am using the current canoe as an experiment for a number of things in this direction, among them being better preservative.

I haven't had any problems using zinc naphthenate, but I am trying to eliminate the VOCs associated with its use. That's also why this current canoe was filled using latex.

The canoe I just filled was dosed with Cuprous Oxide powder mixed in with the first 'soaker' coat of filler. CuO and other copper compounds are currently used as fungicides, algaecides, and insecticides. Other copper compounds were once used as topical antifungal and antibacterial dressings for human severe burn victims - but toxicity WAS an issue when the extent of burns was great.

Metallic compounds have been used as topical antiseptics for centuries - zinc oxide will be familiar to all of us for curing our kids' diaper rash & eczema. The toxicity of the compound depends on the metal used as base - arsenic being very nasty, zinc nice, with many in between them in the periodic table.

Copper is an essential element for metabolism - without it we get sick & die. It works as a biocide by overdosing.
The form CuO that I used is fairly insoluble, but its ionic presence in the canvas should disrupt the metabolism of any fungi that try anything sneaky. Since it doesn't leach, CuO is not an environmental issue till the canvas is removed and disposed of. The amount of copper I used in the biocide is a small fraction of the amount of copper I used in the fastenings.

Of course, with luck, I won't know if it worked for several decades. No news = good news.

I can post a page of links to online papers and my notes on this issue if anyone would care to conduct a peer review or make constructive contributions.

 

[Gil Cramer]

Dacron doesn't rot. Does it cause the wood to rot faster than cotton ? maybe. Does it have other problems? probably. Fiberglass doesn't rot. Does it cause the wood to rot faster then cotton ? maybe. Does it have other problems? probably.
Check the archives on canoe storage -especially at the Dayton Canoe Club to see how much rot they have encountered in their canoes over the years.

 

[Andre Cloutier]

The wisdom according to Pearson is about right, or as Dan Miller is oft heard to say 'your mileage may vary'. |Rips and tears from use notwithstanding, store the boat well and it will last a long, long time.
I'm just thrilled someone brought up the periodic table of elements - finally a reference to University chemistry that i thought i studied in vain......

 

[peter osberg]

Dacron will be less prone to cause wood root, as it is less prone to wicking moisture and canvas deteriorates more quickly with time. Dacron may show underlying construction flaws more easily, but that is its only disadvantage. Dacron's main advantage is in the weight of the covered canoe. Longevity and improved durability are merely additional benefits of dacron (though not as historically authentic as birchbark).

 

[Kathryn Klos]

Oh goodie-- I will post one of my favorite things although it is only sorta on-topic:

http://www.privatehand.com/flash/elements.html

 

[thirsty]

Mileage does vary with care, I have canoes from the '30/ '40 & the canvas is shot, wood has rot.......I also have one, just one, with original canvas having minor repairs, no wood rot '04/'05. If cared for a canvas job, done properly, will last a long time. And at my age, all my canvas jobs will outlast me. My opinion; a nice vintage wood canvas canoe should be covered in canvas.

 

[Larry Westlake]

If cared for a canvas job, done properly, will last a long time.

This comparison may be interesting.

Two canoes belonging to friends of mine were both reconvassed by "pros".
One canoe was left out in West-coast rain all year round, uncovered, upside-down. It was heavily used by kids and adults, for extended trips and for beach-play. The canvas lasted 20 years before tearing along the gunwales. Pretty darned good.
The other was stored outside in an open-sided shed with a good roof and lots of air and no rain exposure. It didn't get used much. The canvas rotted in 5 or 6 years.

Personally, I think that the "caring for" performance of the first owner was acceptable - a utility canoe should be able to take this. The second owner's care was exemplary.

I can only conclude that the second canoe was not done properly. People need to really concentrate on exactly what is proper, because that seems to be more important than the care. The first canoe probably would have lasted 40 years with better treatment.

Larry Westlake

 

[Lazy Jack]

I created a rukus earlier on this forum by asking about alternative covering methods and materials. I suggested the use of Sunbrella, a synthetic canvas like material and was promptly (and exhaustively) edumecated about the potential flaws of that strategy

My overwhelming impression from the myriad of responses was that canvas is the most sensible choice - alternatives which get around some of the weaknesses of canvas (weight and hydrophilicity mainly) have their own inherent drawbacks no less significant than the known issues with canvas.

I plan on ordering the mildewicide treated canvas readily available somewheres near Atkinson Maine.

 

[peter osberg]

May your back forgive you for your choice. On the bright side you will be able to revisit your decision sooner rather than later. My experience with mildew-cides have been disappointing (in their longevity), those heavy metals being the exception. The internet has its advantages, however I doubt I would have gone on to the trying various materials, and methods 30+ years ago, with all those cautionary voices I see being posted. But when hoisting around my (much lighter) canoes my back is grateful I did not keep using canvas.

 

[thirsty]

By using a material other then canvas, a wood canvas canoe is repaired, or made servicable. But it is not restored, nor is it preserved. By definition a restoration is to bring something back to its original or former self. I would argue, using anything other then canvas is a repair.

"The Wooden Canoe Heritage Association is a non-profit membership organization devoted to preserving, studying, building, restoring, and using wooden and bark canoes, and to disseminating information about canoeing heritage throughout the world."

We own composite canoes and wood canvas canoes that we enjoy very much, each serves its purpose. Long carries are more fun, (fun ?) when my canoe weighs 23 lbs. But nothing, nothing compares to paddling our vintage, wood canvas canoe,...on a moonlit lake,....me and my bride,.....we dance........where was I? I'm glad the canoe is preserved, as well as the memories.