Should I use thinned linseed oil on interior planking & ribs

[Howie]

I've been in the habit of adding thinned linseed oil to the outside of the hull's planking (theoretically it restores some oils to the wood & thereby flexibility) prior to canvassing. But I do so after the inside of the planking & ribs are already varnished. But it just occurred to me to wonder if I should also use linseed oil on the interior as well. And if I do so how long must I wait for the linseed oil to completely dry - I'd want to be sure the varnish adheres to the wood properly.

 

[John Sand]

My experience with thinned linseed is to brush it on until it stops absorbing, then wipe off any excess. I would give it a few days at least to dry, though traditional varnish should help it cure.

 

[MGC]

If you ever applied BLO thinned or otherwise to a piece of cedar, let it dry and then cut it open, I wonder what you would see? How much does it actually penetrate the wood?
I apply it on the outside of the hull but I blend it with turpentine and mineral spirits. This blend penetrates and also dries. It's my experience that straight up BLO just gets tacky and that it will eventually turn black. The blend I use does not do that. I should mention that I apply it warm.
WRT the inside of the hull, I like to apply thinned varnish. I presume that filling the pores of the wood on the inside of the hull with BLO would reduce or even prevent the absorption of the thinned varnish. For me, that is a non-starter. I would not put the oil inside the hull before varnishing.
On a Rushton, sometimes I apply shellac under the varnish...but only because that was how his hulls were finished. I don't think there is any true benefit other than achieving a particular color of the wood.

 

[dtdcanoes]

Well, the oil question. It seems there are way more ways than to skin a cat. I do the outside first with BLO , thinned a third or so and not slopped on as there always seemed to be a good residue from its previous life. Then I do the interior after wiping away any seepage to the inside . The interior is all but ready for varnish before the oiling. I have always used raw linseed thinned similarly and generously applied, and wiped down after several hours. A swipe of the thumbnail will show any excess that will be wiped away later. I tried warming the oils before, but became so fearful of the heating process, just couldn't persist with it. And the heated , highly polymerized feature of BLO did not seem to be a very natural process. More importantly, I have never had an issue with varnish bonding , color, wood density etc. . I did the MGC test long ago and while I do not recall the specifics, I chose to go raw and thought the artificial drying feature of the BLO was not the best rehab for old cedar.
Going to kiss my cow now.
Dave

 

[MGC]

Well, the oil question. It seems there are way more ways than to skin a cat
Going to kiss my cow now.
Dave

Right? This topic has come and gone a thousand times here on this forum and before that, on the old one. We all seem to have our way of doing this. For me, the reminder not to use straight BLO is my pick pole. Years ago it was a nice clean and beautiful Snow & Nealy pole that I decided to protect with straight BLO. Of course it turned black. every time I look at it or use it I am reminded not to do that again.
The heating thing is something I picked up from Rollin and Jerry's book many years ago. I'm pretty sure Rollin has his oil can sitting on the stove in his shop. I use one of my old camp stoves to heat it up. I suppose I should worry about the heat and the oil but I also use a propane torch to tar my skis, to remove fiberglass and to solder plumbing.
The blend I use penetrates well and firms up, something that BLO does not do. I learned the blend from refinishing antique furniture many years ago.
Of course now we need to get a few of the tung oil and straight up varnish folks to chime in.
I think we need to start responding as per Benson, "it's your canoe, do what you prefer".

 

[Howie]

Ahhh... I remember now that ive observed that the 1st coat of varnish tends to force out whatever goop is in the wood. I remember i once varnished over waxed wood and there was a ton of waxy residue over the varnish afterwards. Took forever to dry. So I guess I won't use linseed oil on the Interior. Takes a village to remember stuff these days...

 

[chris pearson]

It really doesn’t penetrate enough to help the wood in my opinion.

 

[John Sand]

I'm not arguing for or against its use, but I have experience with how deeply it absorbs. Based on a suggestion I read somewhere, I put the oak boards for a samson post upright in a gallon of linseed oil. After some weeks of this treatment, the oil had been drawn through to the top, a couple of feet above the oil at least. I think there are many factors which would affect penetration, including species of wood.

 

[patrick corry]

John, what species of Oak did you use for the samson post? Here’s an interesting discussion of white oak vs. red oak.

 

[MGC]

Cedar and oak are very different woods. Cedar is far more rot resistant due to its grain structure and it's phenols. It does not absorb the way that oak does. Try standing a stick of cedar in a bucket of ,BOL and see how much it wicks. I'm guessing not much.

 

[Andre Cloutier]

Of course now we need to get a few of the tung oil and straight up varnish folks to chime in.

Only use tung oil on restorations, and new builds sitting on the form for a while - and Pearson covered the varnish only so i guess we're done.
Unless someone with more time wants to debate the scientific merits with discussions of lignin and the like. I'm out.

 

[shelldrake]

I've always used thinned varnish to seal the outside of the hull before canvassing. My thought is that I am trying to seal the wood to prevent the absorption of moisture. I'm not sure that oil does a good job of that.

I too rubbed-in BLO on my newly constructed spruce setting pole. It also turned black and gets moldy.

 

[John Sand]

I used white oak, quercus alba.

John, what species of Oak did you use for the samson post? Here’s an interesting discussion of white oak vs. red oak.

Cedar and oak are very different woods. Cedar is far more rot resistant due to its grain structure and it's phenols. It does not absorb the way that oak does. Try standing a stick of cedar in a bucket of ,BOL and see how much it wicks. I'm guessing not much.

Maybe someday if I'm bored and have material handy. I've owned boats planked with cedar, it does soak up water well.

 

[MGC]

I think you're right. I know that my 20 footer picks up a lot of weight on a 3 or 4 day trip. I'm guessing it gains at least 10 pounds. It feels like 50 on a carry.

 

[Dan Miller]

I think you're right. I know that my 20 footer picks up a lot of weight on a 3 or 4 day trip. I'm guessing it gains at least 10 pounds. It feels like 50 on a carry.

But the question is whether the bulk of the water is soaking into the cedar or the canvas - my bet is the latter.

 

[MGC]

But the question is whether the bulk of the water is soaking into the cedar or the canvas - my bet is the latter.

I 100% agree. If it was the wood the varnish would bubble off and decolor. I've had canvas do that, but never wood.

 

[shelldrake]

Sure would be nice if there were some way to waterproof the inside of the canvas before stretching.