treat planking prior to recovering?

[David Dannenberg]

My wife and I are making progress on our 1952 17' OCTA.

We plan to recover it soon. We plan to use Dacron for ease of installation--heat--and weight saving over cotton canvas. Have seen two done this way and they are gorgeous. How resistant they are to tearing remains to be seen. That said, anyone who has experience with Dacron or opinions based on actual observation please chime in and let us know whether you think that Dacron is a good or bad idea.

Regardless of cover material, we are interested to know what, if anything, people like to use to treat the planks on the outside (prior to covering, obviously). The wood on this canoe appears to be raw, except where varnish has seeped through from the inside. I have read of people coating the planking variously with varnish and with boiled linseed oil.

Does finishing the planking make it more pliable (or conversely, more brittle)? More rot resistant? I suspect we could add a lot of weight to the canoe by saturating the planks; they are roughly finished and white cedar is a pretty open grained material so I suspect the planks could absorb an awful lot of finish. The question is what is the benefit?

Any advice or opinion appreciated.

Thanks.

David

 

[peter osberg]

I never bothered to do much to the outside of the planking, it just seemed unnecessary when the dacron does not wick moisture the way cotton fibre does. If you use canvas then it may be of more value. I am a convert to the weight savings, durablity, and longevity of dacron and posted a routine on this forum a number of years ago. If lots of rocks are in your canoe bottom's future, then you can beef up the abrasion reistance with your coatings and layering. I have also recovered for lightness to make unwieldy heavy canoes managable (18 ft chestnut that is now 49 pounds and doesn't gain weight)

 

[Dave Osborn]

There is plenty of chatter on the subject on this forum in the past.
May well be worth using the search option a on oiling a hull, varnishing a hull, and canvas vs Dacron.

Personally, I use canvas and varnish the hull. I use canvas because it is traditional, and forgiving, although I use a non-traditional filler that has proven, over time, to work well. So I guess, I'm not a purist to the farthest degree. Canvas also is more forgiving, in that it hides many of the hull anomalies that are inherent in most vintage canoes. With Dacron, plan to see tack heads, hammer blossoms, planking seams, hard edges, etc. But if your hull is very fair, as on many new built canoes, you may not notice them.
A heavier Dacron will help in hiding these.

I varnish the hull vs oiling. My research has found that organic oils like linseed oil are food for mold and mildew.... the death sentence (over time) to raw untreated canvas. Dacron is a synthetic and is not susceptible to rot due to mold and mildew. Since (IMHO) main purpose of hull treatment is to prevent water absorption into the planks, which adds weight. I feel that the varnish accomplishes this.....at least as well as linseed oil.
There are many opinions, and ways to skin a cat.... The bottom line is that we all love paddling wood!

 

[David Dannenberg]

Thanks Dave and Peter. FWIW, the canoes I have seen with Dacron coverings are completely smooth--evidence of a fair hulls, careful Dacron covering work, and thorough filling and sanding.

The point about oil being something that may attract mildew over time is a good one. Moisture won't effect the Dacron.

Will moisture that finds its way between the planks from rain or a capsize become trapped between the planks and cover and encourage rotting of the planks, or will any such moisture just drain and dry out when the canoe is left on a rack upside down outside to air? I guess the same question can be asked of canvas--water that makes its way in from the inside of the canoe will not escape through the canvas!

But will a coat (or several) of varnish on the planks--regardless of covering material--help prevent the planks from absorbing water in the first place? The outside of the rough planks are so porous that it seems that a coat of varnish won't really seal them anyway...hmmm.

 

[pklonowski]

Does the outside surface just need to be sanded, so it's smoother?

 

[David Dannenberg]

It is smoothish. Like sawn unsanded wood. Dimples around some of the clinch nails and a few abrasions.

 

[Dave Osborn]

I like to store my canoes right side up for a week or so before turning them over. I think that gives the moisture a chance to evaporate better than if it is upside down.