Paint for interior of SOF canoe - or?

[Greg Nolan]

I am building a 14' skin-on-frame canoe – white oak ribs and stringers; cherry for seats, decks, thwarts, floorboards; 9 oz. white polyester fabric. The frame has just come off the building form and still needs a bit of work before finishing and further construction:

IMG_E6360 s.jpg


I will be varnishing the wood – probably Rust-oleum's Varathane Ultimate Spar Urethane. I will be painting the exterior with a colored paint. The canoe will be stored indoors when not in use.

I have two concerns about paint bleeding through to the interior of the polyester skin.

First, will paint bleeding through cause the polyester skin to adhere or stick to the frame? The skin should be attached to the frame only at the gunwales and stems, and otherwise should be free to shift a bit. Will this be a problem?

Second, how is the interior of the polyester skin to be protected against getting dirty, and against wear and tear?

I read that colored paint bleeding through from the exterior can give a blotchy interior appearance, which can be prevented by applying a first coat of white paint which is essentially invisible, even if blotchy if and when it bleeds through. But does blotchy bleed-through paint provide any protection against anything? If not, what might be done? Or just leave the interior of the polyester alone?

[UCanoe_2]

Re: Paint for interior of SOF canoe - or?

Nice looking canoe, Greg! If you are building from plans, suggest you consult the designer about your questions.

My two cents worth of opinion: After applying finish to the frame, you could wax areas you don't want the skin to stick to. I would use good ol' Johnson's paste wax for floors, although it appears this product may have been discontinued and/or become expensive. Try to use a pure paste wax, and not automotive wax that has polishing compounds and other ingredients.

[pez_leon]

Re: Paint for interior of SOF canoe - or?

When I built my Gentry SOF Whitehall I wasn't sure what to do about the interior fabric and so left it unfinished. Sure enough, it does get dirty, and I wish it had a coat of paint on it. I think I recall reading somewhere about painting the raw fabric before it is even brought to the boat for installation. I might consider that if I were convinced that the hot ironing used to shrink the fabric to the frame wouldn't damage the paint.
Sorry for not having better advice, and best of luck with it!

- James

[Jfitzger]

Re: Paint for interior of SOF canoe - or?

I built Gentry's Ruth and used Duraback to coat the outside. It's basically a smooth truck bed liner. It's ridiculously tough, didn't bleed through at all, a bit heavier than paint would be and a pain to apply. There is nothing on the fabric on the inside but I haven't had a problem keeping it clean. I do launch off a dock and use it for exercise. A canoe is far more likely to see muddy feet and dirty packs.

Painting the fabric before attaching seems a terrible idea. There is no way that it won't inhibit the heat shrink. I would spray the interior with the same spar varnish used on the frame. Varnishing Dacron has a good track record and you wouldn't have to worry about masking the frame. Brushing would be possible but would suck to do. A $30 jam gun and an air compresser would make quick work of applying finish.

[Jfitzger]

Re: Paint for interior of SOF canoe - or?

Also, that frame looks beautiful.

[Hull Speed]

Re: Paint for interior of SOF canoe - or?

It will depend on the paint and on the fabric, but bleed-through does not have to be blotchy. I tested several paints for my rowboat before finding one that would bleed through evenly. I don't think adhesion to the frame has been a problem; in fact, I'd think movement of the skin against the frame could cause abrasion of the fabric.

Ken

Robåt_small.jpg

[oldcodger]

Re: Paint for interior of SOF canoe - or?

It will depend on the paint and on the fabric, but bleed-through does not have to be blotchy. I tested several paints for my rowboat before finding one that would bleed through evenly. I don't think adhesion to the frame has been a problem; in fact, I'd think movement of the skin against the frame could cause abrasion of the fabric.

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^ Good point.

To quote from Dave Gentry's instructions for painting his Ruth design.

After his advice on using oil based paint or varnish, he writes:-

Optional A scrim undercoat of "PL Premium Construction adhesive"(or similar) along the keel and chines will greatly enhance the "wear factor" of the fabric areas which typically take the most abuse. Apply it thinly to the outside of the fabric, work it into the weave with a plastic scraper, and allow it to thoroughly cure before lightly sanding and applying your topcoat of paint or varnish. Wear gloves and make sure there is good ventilation.

* This construction adhesive is a very tough fabric coating, but has no UV resistance, so a top coating is necessary.

* Some folks have undercoated the entire hull with this product. I rarely coat more than the hull below the waterline.

* Makes a great seam sealer, as well.

[Nicholas Carey]

Re: Paint for interior of SOF canoe - or?

Corey Freedman, up in Anacortes, Washington, has been building, and teaching how to build, skin-on-frame baidarkas and umiaks, and other skin-on-frame vessels for probably 25+ years. He skins them with ballistic nylon, and coats it with a 2-part urethane, usually tinted with artists pigments (available from Kremer Pigmente). No paint.

https://www.skinboats.org/

https://www.skinboats.org/urethane-application-

https://www.kremer-pigmente.com/

(US site at https://shop.kremerpigments.com/us/)

https://www.youtube.com/watch?v=LrNB-wfaZNo