Strip varnish without removing canvas?

[Brad Fisher]

A friend has asked me to revarnish the interior of her Old Town, but not to re-canvas it. Truth, it doesn't need new canvas at this point. Is it OK to use a chemical stripper on the interior if I'm leaving the canvas on? Any danger of damage to the canvas or filler if the gunk leaks through?

 

[Fitz]

I did this once years ago and I would not recommend it. I had spots where the stripper went through the filler and lifted the paint.

Fitz

 

[Brad Fisher]

As I feared! So it’s sand, steel wool, scotch pad thingy. Thanks!

 

[Todd Bradshaw]

Technically, steel wool is not a good choice for use on boats as it tends to leave tiny particles which will later rust and leave little spots under your finish. Granted, there are still folks who use it, but be aware of the potential for problems later. They do make bronze wool, if you can find it, but it may be a lot easier to arm yourself with a batch of Scotchbrite-type pads with assorted coarseness. One good source for such stuff is a tool rental place like they have at most Home Depot stores. You can buy big disks of the stuff designed for rental floor sanders and cut chunks out with scissors as needed to use by hand.

There are also people who strip old varnish using flat steel scrapers (carefully sharpened) and do a nice job of it, but I haven't tried it yet.

 

[Brad Fisher]

I have a set of cabinet scrapers, and have used them on canoe planks and ribs. I don't like dragging them over tack ends though. Scotch-brite is the stuff. Thanks!

 

[MGC]

I once bought a Morris that had a very new canvas on it but it really should have been stripped and varnished before it was put on. I pulled the seats and thwarts and sanded it out before varnishing it. It came out just fine. It retained much of the old patina but it was protected by the many new coats of varnish. You could do the same.
I used my palm sander for most of it. I used sandpaper over foam sanding blocks for the areas that were a bit harder to get at. I'll agree with Todd. Inside the hull I stay clear of steel wool. Occasionally when I am trying for a really polished finish I use it on the thwarts and seats but I am really careful to clean up the steel wool dust.
As an aside, the picture you posted does not give us a really good luck at the hull. To my eye it looks like there is crazing in the paint/filler. Was it recently repainted? Sometimes we try to avoid canvasing when canvasing is really what is needed. If that is the case. If the canvas is quasi marginal, perhaps you should just go for it and do the whole job. If the canvas is off you can do a bang-up job on the hull, repair any small issues and properly strip and revarnish the hull.

 

[David Satter]

you sure that's canvas? Might be a bad fiberglass job.

 

[Gil Cramer]

you sure that's canvas? Might be a bad fiberglass job

With the strippers available today, you are not likely to hurt the exterior covering.

 

[MGC]

Gil, do t

With the strippers available today, you are not likely to hurt the exterior covering.

Gil, what sort of stripper are you using?

 

[David Satter]

Even with the safest strippers today I wouldn't try it if its canvas. I did just strip another canoe yesterday, without the canvas on. Using Total Strip by Total Boat. $79 a gallon I really like this stuff. I was able to do the whole canoe with one gallon. Though there was only one coat of varnish on it. Not sure how it will work with thick layers of varnish.

 

[rober]

Technically, steel wool is not a good choice for use on boats as it tends to leave tiny particles which will later rust and leave little spots under your finish. Granted, there are still folks who use it, but be aware of the potential for problems later. They do make bronze wool, if you can find it, but it may be a lot easier to arm yourself with a batch of Scotchbrite-type pads with assorted coarseness. One good source for such stuff is a tool rental place like they have at most Home Depot stores. You can buy big disks of the stuff designed for rental floor sanders and cut chunks out with scissors as needed to use by hand. There are also people who strip old varnish using flat steel scrapers (carefully sharpened) and do a nice job of it, but I haven't tried it yet.

Bronze wool is available at Jamestown Distributers.

 

[David Satter]

I like the plastic putty knives , you can cut them to a nice size to fit in tight places and between the ribs. Then clean up with scotch-brite pads.

 

[Brad Fisher]

Thanks for all this information. I decided to skip the chemical stripper and use scrapers, heat, sandpaper and plastic scrubbers. Once we got all the loose stuff off and focused on the ugly spots, we ended up with a decent surface. And good varnish covers a multitude of sins, as they say. Not museum grade, of course, but the owner, a river guide on the middle Allegheny, was very pleased with the work.