Removing Varnish from Gunwales?????


I just bought a used canoe that has wood gunwales that the previous owner varnished.

I am in the process of removing the varnish so that I can refinish them with an oil finish.

It’s been a lot of work. I have been using an orbital power sander with 60 grit sandpaper and it is slow-going. Seems really hard to get the varnish off completely, as I guess it must penetrate fairly deep.

It is made more complicated by the curves and corners in the gunwales.

Any suggestions on how to proceed that may make things a little easier? Some sort of chemical perhaps???

Also, frankly I am not sure when I am down to bare wood or if there is still some remnants of the varnish. Bare wood is white but there seem to be some areas that still have a colored hue to them which I assume could be areas where the varnish has penetrated and where I may need to sand more…or am I being too thorough and does the varnish really only sit on the surface?



Paint remover
Take the gunwales off and use a stripper. I don’t do much of that so I don’t know what stripper to recommend. Read the cans, check online, or perhaps some of our more wood-worker types will have a recommendation. You’ll still have to sand, but if you can at least get the surface layer thinned down, it should be easier.

You might try a post over on the wood canoe heritage association forum. Those guys deal exclusively with wood and must know how to get varnish off. They are at

Or, throw $60 or $80 at a piece of quality lumber and cut yourself some virgin gunwales. But, you still gonna have to sand 'em.

Hurry up. The rivers are up!


I did this same thing last winter

– Last Updated: Mar-30-10 9:15 PM EST –

I removed the varnish from every piece of wood on a canoe late last winter, mostly with careful use of a small belt sander, followed up by hand sanding. I actually went out and bought an orbital sander for the job, and found it to be nearly useless, since it was slow and the working-contact area of the sandpaper on the disk was too small to keep the paper "stuck on". The belt sander was a lot better, and I really had no problems at all with "removing too much" material. You'll need to have a delicate touch, though, and don't try to remove every little trace of varnish. Streaky traces will come off with ease during final hand sanding using the old wooden-block method.

I have no experience with stripper.

I wouldn't bother trying this without removing the gunwales. You can also do a much nicer job of re-finishing with the gunwales removed. The sander I used has a very small-diameter front roller, which with the gunwales taken apart, could be used to clean out the inside edges of the drain holes.

Being a fussy sort of person, one thing I am careful about when re-assembling gunwales is to make sure the screws don't cut any "new" threads. No point in tearing up wood that was previously undisturbed.

Recent topic

I didn’t bother to remove the varnish
from the gunwales on the used canoe that I just got, I wanted to use it immediately and the underside of the gunwales was nearly free of varnish. I don’t have the time or work area to remove the varnish, so I just Watco oiled over everything after a quick cleaning.

I didn’t need perfect, just protected.

I realize that the gunwales could self destruct and explode off of the boat and any time. That’s life.

I also realize that my canoe maintenance license could be revoked at any time.

I guess maybe I ought to use some stripper. Was trying to avoid it because I don’t want to take the gunwales off and don’t want a mess on my boat; however, since I have already gotten most of it off with my sanding I think that I may be okay with just a bit of stripper and that it may not make a huge mess. I have been able to get most of it off, but the stuff is freakin’ tenacious. Hopefully this will allow me to use the stripper without making a gooey mess.

I will pick some stripper up today and just be careful about getting it on the gel coat of the boat. That will be crucial I think because I don’t imagine it wil do very good things for the gel coat.


Just revarnish
Just lightly sand with 100 grit and then 220 and revarnish with real marine spar varnish (nothing poly) with as many coats as you want, scuffing between coats.

Or are you in with the snake oil crowd? :wink:

You could try using a scraper: they’re much faster than sandpaper and when used properly give about a #300 finish. I like the carbide ones: they last a lot longer than mild steel although, if you are only going to do one boat, you’ll likely get away with the less costly one.

Here’s an example:,310,41069&ap=1

Why don’t you just varnish it again? The fact that you are having so much trouble getting the old varnish off should tell you that it is tough stuff. Sand it and varnish. Use real varnish not poly. Sand between coats and put on three or four. Use painters tape to cover the fiberglass and catch the runs. Others will disagree, I’m sure, but I’ve always felt that the manufacturers are oiling gunwales because it’s cheaper. They don’t want to spend the time to do it right with varnish. Wood canoes are all varnished - for a reason - it works good! Just my $0.02 worth.


I’ve had a lot of experience using strip
Don’t take the gunnels off, too much work. Besides, what if you crack one?

Use duct tape to protect the hull Run a strip right down the gunnels,inside and out. Then use masking paper and tape to further protect it. You can lay a drop cloth or plastic in the bilge of the canoe. Stripper will attack the gel coat and ruin it.

I would use a new type of chemical called “Easy Strip”. It doesn’t have the VOC’s of regular stripper and is easy to apply. You must cover it with plastic to let the chemical soak and work.

If you use regular paint stripper wear gloves, lay it on heavy and let it work. Then use steel wool and alcohol to scrub off the residue. Sometimes it take several applications. Final wash with water.

oil as is
since you’ve got it sanded down and it sounds like what’s left is in the pores, just oil over it and see how it comes out.

For a lake and smooth river boat,
and for an owner whose handling of the boat does not involve a lot of banging around, varnish may make good sense.

But when a canoe’s use includes much banging and scraping, then varnish is going to get cut and scraped off. One could do varnish touchup every month, but it’s easier just choosing oil in the first place, and swabbing more oil on when surface damage occurs.

That’s why I switched from varnished gunwales, varnished floors, and varnished furniture, to oil. Easily repaired.

and the myths continue…

– Last Updated: Apr-02-10 8:34 PM EST –

A flexible and hard finish (real varnish) is somehow less effective in protecting the wood from abrasion (and UV, and staining) than no finish at all...(oil).

I touch up the varnish maybe every 8 or 10 years.

You guys oil every other week....?

Are you kidding? Varnish gets whacked
or abraded and you just ignore it? And nothing happens to the wood underneath? You must live in outer space.

I use varnsh on paddles, and I don’t wait years to cover damage to the varnish.

If you prefer varnish, that’s OK, but it’s much easier to maintain ash gunwales with oil.

One Reason for Preference

– Last Updated: Apr-03-10 5:52 PM EST –

You have to remember that on a wood/canvas canoe, you've already gone to great lengths to cover the entire outside of the hull with canvas, finishing "putty" and paint, and the whole inside needs a long-term coating too since it would be silly to have to clean off all the dirt before every re-oiling. Add to that the fact that there are countless wood joints into which water could seep if not completely covered, and those joints can't be loosened to allow oil to easily flow in as can be done with gunwales. With all those reasons for using varnish on the interior of the boat, it is only natural to varnish the gunwales at the same time. However, when the only wood on the whole boat is in the thwarts and gunwales, using oil starts to look a lot more attractive than it would otherwise. I think you are comparing apples and oranges.

I also think what you say about varnish being so durable in sunshine is highly overstated. Our family had a wood-canvas Old Town rowboat when I was a kid, and it was stored outside during the warm part of every year. Spar varnish on the inside of the boat held up just fine (well, it was in crappy, blistered condition to begin with, being 25 years old, but it did not rapidly get worse), but stored upside down, the boat's gunwales and transom really took a beating from the sun, and the varnish was completely shot after every couple of years. I've heard that oil finishes get more and more popular the farther south you go, for that very reason, but that up north, varnish is preferred.

Where did you hear that oil users are re-applying the stuff every couple of weeks? I take it you actually believed that? I was lazy last year and never oiled the wood on my guide-boat at all, but did enough trips in that boat to log a few hundred miles, and this year, water still beads up and runs right off. If I kept the boat outside when not using it, I'd be a lot more diligent. As it is, I normally apply oil twice a year, and that seems to be more than adequate. Touch-up work couldn't be simpler (there's NO preparation or cure time required). In the six or eight years I've had that boat, I still have far less time invested in re-applying oil than would have been needed for one application of varnish, let alone the touch-up work to fix chips and scratches in the finish.

I know this is hard to explain to you, so I'll try to make it clear that I think varnish is GREAT on wood/canvas canoes. It just isn't the only reasonable option when there's very little wood to protect.

By the way, the gunwales and thwarts I re-finished last spring look MUCH better than they did with the stained and ratty-looking 10-year-old varnish I removed, and there will never again be the need to spend a whole week of evenings restoring the wood to its present appearance. Since the boat is only out in the weather when being used, it will still be in fine shape when the person who owns it can no longer paddle, as long as a few minutes per year are spent applying a little more oil.

We’ve been down this road before…

– Last Updated: Apr-03-10 9:48 PM EST –

It is obvious that I won't change any minds.

Varnish is used pretty much exclusively on wooden boats and has been for hundreds of years for many good reasons. Boats at sea, boats on moorings in the sun all summer, boats on moorings in the rain all summer, boats on docks, sailers, mahogany runabouts, canoes, kayaks, even guide boats.

Varnish is used on those pretty wood kayaks specifically because it is loaded with UV blockers to protect the underlying epoxy.

You only hear of oil in the wood gunwaled plastic canoe forums. Right next to the advice on how to replace rotted ash gunwales.. ;-) Oil is rarely ever mentioned among wooden boat nuts except maybe thinned to give some life back to dry planking. Even then there are concerns about it acting as feed for mold and mildew.

I'm just trying to bring you up to par.

I'll tell you what. I have some extra pieces of ash and mahogany around. If I feel ambitious, I will finish some up with varnish, poly, snake oil, whale blubber and whatever else I can find around the house and leave them outside for a period of time and report back with photos.

I think this has been attempted before, but the oil wasn't working too well, so we may never know the results.

Rotting Gunwales

– Last Updated: Apr-04-10 12:03 AM EST –

I still don't dispute that varnish will "win" in a long-term comparison on the effectiveness of a single application. Also, the same reasons I provided for using varnish on an all-wood boat apply to your examples, so if you had read all of what I wrote you'd know that your examples do not dispute anything that I believe. Comparing the two methods long term after one application is totally pointless and can only seem relevant if you have an axe to grind. Oil finishes are not the right choice for whole-boat protection or single-application protection, so why would anyone be surprised that oil is not discussed by wood-boat enthusiasts? This is a point that cannot be ignored but one which you insist on ignoring anyway. If you actually pay even a little bit of attention to what I've said about the usefulness of varnish, you will see that we don't disagree nearly as much as you insist on believing.

The thing about rotten gunwales is that time and time again, it's something seen on boats which have been neglected and stored outside, regardless of the finish. It's absolutely true that the rot will be slower to get started on a neglected boat with varnished gunwales, but the real issue is to not neglect your boat in the first place. Gunwales are what wood/canvas boat restorers need to replace more often than anything else because that's the place where water seeps in, but is anyone using that as "proof" that varnish is a bad choice? The finishes are not comparable in any way, except that IN THOSE INSTANCES where using oil is a logical option, both finishes will be effective IF both are maintained to the necessary degree. Again, trying to compare the two methods under any other circumstance seems like a case of intentional missing of the point.

I just remembered something else that I think is worth mentioning. You have often made a big point of the fact that there are wooden canoes and other boats in perfect condition, even though they are 100 years old or more, and each time you say it demonstrates the durability and longevity of varnish. I think that it's not a testament to the virtues of varnish as much as it is to the fact that a few boats have been "lucky enough" to have been well cared for or stored under good conditions for a long time. I remember my first family vacation as a kid in northern Wisconsin in about 1970, where some of the small, crystal-clear lakes were positively littered with sunken wooden boats. You'd also find the remains of boats back in the woods. I thought those boats were "so cool" because of the history they represented. As near as I ever was able to figure out, up until 20 years before, all the resorts had fleets of wooden boats, and all the cottage owners had their own wooden boats. One old guy said that nearly all of those boats were gone, having rotted away because they needed far more care than the average person would provide. Basically, a finite lifespan of boats was all that people expected back then, until aluminum and fiberglass came along. I asked my dad about this and he said that when he was a kid, boat-building was a common skill, and that all of the boats he ever saw back then were made of wood. However, he also said that nobody owned an "old" boat as measured by today's standards. They just replaced them in matter-of-fact fashion when they got too ratty. Throwing out boats was "normal". You say that you only hear about rotting gunwales on plastic-canoe forums, but that would NOT be the case if it weren't for the fact that probably less than 0.01 percent of the canoes out there these days are made of wood, and if not for the fact that nearly all of THOSE few examples are owned by enthusiasts. In short, there's a whole lot more behind the survival of old wooden boats than the material that protects the wood.

Pros and Cons
To quote you, “Gunwales are what wood/canvas boat restorers need to replace more often than anything else because that’s the place where water seeps in, but is anyone using that as “proof” that varnish is a bad choice? The finishes are not comparable in any way, except that IN THOSE INSTANCES where using oil is a logical option, both finishes will be effective IF both are maintained to the necessary degree”.

Actually, I think the most replaced part would be the ends of the stems and decks, where the varnish brush doesn’t reach and builders didn’t bother to varnish the end grain of the stem during construction (most models, depending on construction of the deck/stem joint).

But yeah, this is exactly the “proof” that the snake oil proponents were using…something about the varnish cracking and letting moisture in, so whatever you do don’t use varnish on your gunwales…

Oil requires multiple applications a year - how is this a maintenance free or less maintenance finish?

Oil offers no protection to the wood against abrasion.

Oil will turn black or discolor or allow the wood to turn black or discolor, or both.

Oil offers no UV protection.

Oil is prone to mold and mildew.

Oil likely does not penetrate the surface much.

So how is the use of oil effective and logical?

The patina of a oiled surface is nice, and it might work on decks or floors of boats where you don’t want a slippery surface, but I still wonder why anyone would put it on gunwales.

I was reading a boat building book last night and guess what? - these drawbacks for an oil finish on a boat were highlighted.

See you again in six months when the topic rolls around again :wink:

See you in six months?

– Last Updated: Apr-04-10 1:01 PM EST –

Actually, talking about the pros and cons of oil is a first for me, so it might also be a "last". I don't think we are really that far apart on what varnish is good for, and you are certainly correct that oil is no substitute for varnish if you want to "leave it be" afterward. You say that "But yeah, this is exactly the "proof" that the snake oil proponents were using...something about the varnish cracking and letting moisture in, so whatever you do don't use varnish on your gunwales..", I hope you realize I have said nothing of the kind, ever. I don't know anyone else who has either. As for oil, as long as I continue to see that the people who actually monitor the condition of their boats are not having their oiled gunwales turn rotten, the method seems "good enough" for me. As far as efficiency of time goes, as long as multiple oil applications over ten years adds up to a total work time that is less than what's needed for a single application of varnish, that's still less time spent on maintenance any way you look at it (other than your way, of course). Anyway, with all the cared-for boats I keep seeing that are in fine shape having oil on the gunwales, I figure on accomplishing the thing, and if I don't, I won't be afraid to admit it.

And I probably won't be back to talk about this subject again, but I sure would like to see some of your canoes someday!

Let’s turn that around.
Varnish requires multiple touchups a year to fix scrapes and scratches- how is this a maintenance free or less maintenance finish?

Varnish protects wood only from the most superficial scratches.

Varnish often darkens and discolors as much or more than oil. A varnish coating is never perfect, is soon pocked, and then allows wood color changes or rot that is more visible than what occurs on oiled wood.

UV protection for ash gunwales really isn’t much of an issue, but there are a few outdoor oils that offer the UV protection claimed for varnish. (I’ve varnished epoxy coated spruce thwarts and I’m not impressed with the “protection” I’m seeing.)

The oils I’ve used are not prone to mold and mildew. If the gunwales are not oiled yearly, then some superficial mildew may appear on the ash surface.

Varnish does not penetrate the surface much.

So, except for aesthetic concerns, or just because you like to varnish, how is use of varnish better for ash gunwales that are constantly getting scraped and beat up?

I specified sitka spruce gunwales on one canoe, and they HAD to be varnished because spruce is much more inclined to mildew and rot than ash. The varnish took a lot of damage, and scraped off very fast where my (varnished) paddle shafts contacted the gunwales. I never saw any indication that the varnish protected the spruce from scrapes and bangs. I had to do touch up varnishing several times a year. Possibly if I had removed the gunwales and coated them with epoxy, and then varnished them, the surface would have been hard enough to protect the spruce.

Varnish is better for soft woods, but for any wood that is hard to begin with, oil works well. I have harpsichords and a clavichord where I saved a world of trouble by using oil rather than varnish. They were made around 1980. The surfaces are hard, scratch resistant, and most important, much more quickly and easily repaired than would be the case with varnish.