Wooden paddle finish voodoo

Advice
#12

Penetration mythology

– Last Updated: Aug-16-09 1:06 PM EST –

There are a lot of myths regarding the penetration of oil and other finishes into wood. The truth is that the only substantial penetration you'll get is on end grain, where it can wick in along the cell structure. On flat grain, you get a few thousandths of an inch of penetration at best in most woods. On coarse-grained woods like oak, you'll get more penetration where there are exposed pores, but you still get very little elsewhere.

For the skeptics out there who may think I'm blowing smoke, here's a really simple test:

- Take a sharp plane and set it to make a .002"-.003" shaving.

- Take an oil-finished paddle or test piece and count how many plane strokes it takes to get down to bare wood. In my experience, two or three is about it on face grain.

While it's true that raw linseed oil stays liquid longer and will at least theoretically penetrate farther into the wood, whether you end up with .004" of penetration or .008" of penetration doesn't make a whole lot of difference, certainly not enough to justify putting up with a finish that takes forever to cure. Applying a faster curing finish over it will increase the curing time of the raw linseed oil dramatically, as it will cut it off from the oxygen it needs to cure. "Saturation" will never occur unless you soak the wood in oil for weeks to months and even then it may not fully penetrate an object as long as a paddle.

I haven't found that thinning oils increases penetration appreciably, either. The thinners evaporate too quickly to do much good. They also result in a more porous finish, since the evaporating thinner leaves open pores in the oil or varnish film.

There is one more thing that's important to understand about oils and varnishes; they don't "dry" like lacquer or shellac (where the solvent simply evaporates), they "cure" by combining with oxygen in the air. The resulting finish is chemically different than the original oil or varnish and applying more over it will not dissolve the underlying finish and bond to it. There is a finite window where the best bond between coats can be achieved. If you apply the next coat too soon, you cut off the oxygen supply to the underlying coat and it takes MUCH longer for it to cure. This is what happens when a varnish job is rushed and slathered on too quickly/heavily and it stays soft for weeks or months. OTOH, if you don't apply the next coat soon enough, you won't get any chemical bonding, so you need to sand the surface to enhance the mechanical bond between coats. Oils are somewhat more forgiving, since they don't build up much film thickness, but if you slop on oil and don't wipe it off, you end up with a gooey mess that again takes forever to cure.

For anyone interested in more information on various finishing products, how they work and where they are best applied, I highly recommend Bob Flexner's book "Understanding Wood Finishing". It spells it all out and dispels many common myths.

#13

Seems like you all forgot about PAINT
Paint is the number one wood protective coating these days. It lasts much longer than varnish and is easy to maintain.



Of course then other won’t be able to tell you are using a real wood paddle from a distance and that might hurt your feelings, but it will not hurt the paddle at all.

#14

Oil isn’t always oil

– Last Updated: Aug-16-09 1:09 PM EST –

I did some googling.

This article says that many popular oils, such as Watco and other "Danish" oils, are really just blends of varnish and an oil.

http://www.popularwoodworking.com/features/finish2.html

Another article specifically says Watco is linseed and varnish.

The linked article and others I have seen, along with one paddle maker, say pure tung is very difficult to use. It must be sanded vigorously after every application and many, many coats must be used.

Most of the articles say oil has no UV protecting qualities. Some say it should be applied over bare wood with nothing underneath it.

If any of these are correct, it would seem that if you are going to apply oil, you shouldn't apply an epoxy sealer first. The epoxy will interfere with the saturation and polymerization of the oil, and the epoxy won't be protected from UV by the oil.

What the heck happens to epoxy anyway if it isn't UV protected? Something horrific?

I'm more interested in protecting the wood than the epoxy. Does wood itself need UV protection?

My investigations this summer have not changed my longstanding subjective preference for the feel of oiled grips over varnished grips. But now I wonder certain things. Should I oil the whole shaft? If I do, shouldn't I forbid an epoxy "sealant" underneath it? But, confusingly, if the oils I'm using are really half varnish anyway, maybe I'm back to voodoo and have always been fooling myself about "oil".

Oh, on top of all this, other articles say that "oil" or "varnish" are preferred or not for finishing depending on what kind of wood is being used. Cherry is different from oak. Something to do with pore sizes.

http://74.125.93.132/search?q=cache%3AUkxpObvIAPUJ%3Awww.woodcentral.com%2Fbparticles%2Foil_finishes.pdf+watco+oil&hl=en&gl=us

I guess I forgot my botany. I thought wood was a closed cell structure.

#15

There’s nothing wrong with paint…
…but very few people use it on paddles, either commercial or home-made. I didn’t forget about it, it’s just not particularly relevant to the discussion at hand.

#16

Effects of finish on wood color
I forgot to bring up this issue in my previous posts, but it may be of more or less significance to discriminating paddlers.



I have read that, among varnishes, spar will discolor (yellowy) more than polyurethane. I have also read that different oils will have different color effects over the short and especially long term – though I haven’t seen anything go into exact specifics.



I personally would prefer the finish to have minimal effects on color IF I have spent a lot of time and/or money selecting or specifying my woods for color aesthetics – such as my ebony, bloodwood, curly maple and kauri dream paddle.

#17

Even more answers
"This article says that many popular oils, such as Watco and other “Danish” oils, are really just blends of varnish and an oil.



http://www.popularwoodworking.com/features/finish2.html



Another article specifically says Watco is linseed and varnish."



As I mentioned previously, most “oil finish” products are blends. They typically mostly thinner, blended with varnish and in some cases linseed or tung oil. The only way to know that you’re actually applying an oil finish is to use pure oils.



"The linked article and others I have seen, along with one paddle maker, say pure tung is very difficult to use. It must be sanded vigorously after every application and many, many coats must be used.



That’s complete BS. Tung oil is incredibly easy to use as a finish, as is boiled linseed oil. You wipe it on, let it penetrate, then wipe it off. Each succeeding coat helps fill the pores in the wood, but it won’t build to any appreciable thickness. Perhaps that’s the issue with the author of the article, he’s trying to create a varnish like finish with tung oil, which is a complete waste of time and a poor application for it. As with any finishing product, you have to understand it and use it where it’s appropriate. Lack of understanding is where most finishing myths come from.



BTW, for finishing paddles, I’ve found that there’s no point in applying more than 4 or 5 coats of oil or oil/varnish blend and as few as 3 will do the trick.



“Most of the articles say oil has no UV protecting qualities. Some say it should be applied over bare wood with nothing underneath it.”



Correct on both counts.



“If any of these are correct, it would seem that if you are going to apply oil, you shouldn’t apply an epoxy sealer first. The epoxy will interfere with the saturation and polymerization of the oil, and the epoxy won’t be protected from UV by the oil.”



Correct again, except that the epoxy shouldn’t affect the polymerization of the oil, since all that’s required for that is oxygen.



“What the heck happens to epoxy anyway if it isn’t UV protected? Something horrific?”



It breaks downs and gets chalky, losing all of its strength in the process. If it’s used as a wipe on/wipe off coating on wood (applied like oil), it is somewhat protected by the wood itself. If it’s applied as a film coating (applied like varnish), it’s unprotected and subject to degradation. Depending on how much you use your paddle and how you store it, the damage could take anywhere from months to years to become bad enough to raise concerns.



“I’m more interested in protecting the wood than the epoxy. Does wood itself need UV protection?”



In general, no, as wood is not damaged by UV. Some - perhaps most - woods change color due to UV exposure. Pine turns orange, purple heart turns brown, etc. If the color change is undesirable, a UV protectant will slow the change, but I don’t know if it’s possible to completely eliminate it.



“My investigations this summer have not changed my longstanding subjective preference for the feel of oiled grips over varnished grips. But now I wonder certain things. Should I oil the whole shaft? If I do, shouldn’t I forbid an epoxy “sealant” underneath it? But, confusingly, if the oils I’m using are really half varnish anyway, maybe I’m back to voodoo and have always been fooling myself about “oil”.”



That’s one of the biggest problems with wood finishing, the huge amount of misinformation foisted on the public by finish manufacturers. Calling a wiping varnish an “Oil Finish” is confusing to the consumer and just plain wrong.



To answer your question, if you like the look and feel of oil finishes, either use pure oil or make your own oil/varnish blend. Unless you have a specific need for epoxy, there’s no point in using it. As I mentioned, I epoxy coat the tips of my paddles for durability and use an oil varnish blend on the rest of the paddle. It gives me the look and feel I like with better durability that just oiling the entire paddle. You may prefer a different approach. Now that you understand what these products are and how they work, you can figure out what’s the optimum finish for your needs.



“Oh, on top of all this, other articles say that “oil” or “varnish” are preferred or not for finishing depending on what kind of wood is being used. Cherry is different from oak. Something to do with pore sizes.”



Again, it depends on the application. What you use on furniture or cabinets may not the the ideal finish for a paddle. It also depends on what one is trying to achieve with the finish. Blanket statements like that simply cannot be correct for every application. You need to know the goals of the author and the materials being used.



“http://74.125.93.132/search?q=cache%3AUkxpObvIAPUJ%3Awww.woodcentral.com%2Fbparticles%2Foil_finishes.pdf+watco+oil&hl=en&gl=us”



In this case, the author apparently doesn’t know what he’s using. Because Watco contains varnish, it can be built up slowly by using many thin coats. He also doesn’t seem to realize that the sanding he’s doing is filling in the pores and knocking down the high spots, which is what ultimately produces a fine finish. I routinely apply the last two coats of finish on my paddles using 400 and 600 grit sandpaper. Even on cedar, the results are impressive.



“I guess I forgot my botany. I thought wood was a closed cell structure.”



Yes and no. There are closed cells, but there are also tubular structures. This varies greatly between various species of wood. Sawing/planing/scraping/sanding opens some cells and tubes, which will then absorb a finish. Sanding plows furrows in the wood, which will also hold finishes. It’s a whole 'nuther world at that level.

#18

bnystrom
Thank you for your in depth contributions. Do you mind saying something about your background in this area.



You say that one should use “pure” oils in order to know what you are actually using. That sounds reasonable. But the only oils I’ve heard about so far are tung and linseed (not counting beeswax). You’ve said you use tung.



Not to be argumentative, but one of the authors whose comment about tung you called BS is the same author you recommended earlier, Bob Flexner. He says in the article I linked:



“But tung oil is too difficult for most people to use by itself as a finish. You apply tung oil just like linseed oil or oil/varnish blend, but you have to sand tung oil after every coat, not just after the first, and it takes five to seven coats, allowing two to three days drying time between each, to achieve a smooth, attractive sheen.”



This kind of statement deters a novice like me from even trying tung. Would you mind elaborating on why you are saying tung doesn’t have to be vigorously sanded and dried multiple times. Is it because you are cutting the tung with varnish in the first place?

#19

Epoxy with/without varnish
http://www.oneoceankayaks.com/Epoxyhtm/epox12m.htm

#20

Terrific. Empirical evidence. Thanks.
I have been bothered throughout my summer paddle journey, including this thread, by the lack of empirical evidence to back up claims. Everything seemed to be subjective, anecdotal and/or mechanical confirmation bias. (By mechanical confirmation bias, I mean someone who has shot a number of free throws with two hands, and hence recommends two-handed free throw shooting. She may never have tried one-handed or under-handed free throw shooting.)



If I’m reading the test results correctly, the whitening-cracking-crumbling can only be reduced by applying and leaving on very thick filler coats of epoxy – which of course would add unwanted weight in something like a paddle. It also seems as if varnish does help reduce the degradation, but doesn’t stop it.



Makes me think about whether I want any epoxy or composite cloths on an expensive wooden paddle. Sort of a trade off between ultimately fixing some damaged wood or ultimately fixing some damaged epoxy and cloth. On the other hand, I have 25+ year old wood paddle blades with FG wraps that look perfectly fine. They’ve been lightly sanded and varnished just two or three times.


#21

like
these?



http://www.woodsongcanoes.com/paddles.htm



Best Wishes

Roy



I use the finish Phil uses. He;s the one that told me.

#22

Yet more
"Thank you for your in depth contributions. Do you mind saying something about your background in this area."



It’s pretty simple really, I’ve read a lot about finishes and I’ve experimented with them on paddles and SOF frames.



“You say that one should use “pure” oils in order to know what you are actually using. That sounds reasonable. But the only oils I’ve heard about so far are tung and linseed (not counting beeswax). You’ve said you use tung.”



You can buy pure linseed oil - either raw or boiled - just about anywhere. I don’t recall ever seeing any products advertised as linseed oil that weren’t actually that. Tung oil is another matter, as there are myriad “Tung Oil Finish” products on the market that are wiping varnishes or blends. You can get pure tung oil, but generally you have to get it through a woodworking supplier, as the stuff you find on the shelves at home centers and hardware stores is suspect unless it actually says “100% tung oil” on the container.



“Not to be argumentative, but one of the authors whose comment about tung you called BS is the same author you recommended earlier, Bob Flexner. He says in the article I linked:



“But tung oil is too difficult for most people to use by itself as a finish. You apply tung oil just like linseed oil or oil/varnish blend, but you have to sand tung oil after every coat, not just after the first, and it takes five to seven coats, allowing two to three days drying time between each, to achieve a smooth, attractive sheen.”



This kind of statement deters a novice like me from even trying tung. Would you mind elaborating on why you are saying tung doesn’t have to be vigorously sanded and dried multiple times. Is it because you are cutting the tung with varnish in the first place?”



That’s interesting, but without context, I can only assume he’s talking about using it as a furniture finish, which is his primary business. Personally, I wouldn’t use straight tung or linseed oil as a furniture finish, as it’s not durable enough and I wouldn’t want to be renewing it constantly.



As a paddle finish, none of what he said is true unless you’re determined to have a flawless, furniture-grade finish on your paddle. I used straight tung oil on a number or paddles (and straight boiled linseed oil, too) before I experimented with blends and ultimately switched to them. It was a wipe-on, wipe off process, just as with linseed oil; there were no special techniques or other gyrations involved. It couldn’t have been easier.



I understand your confusion, as the subject of wood finishing is full of myth, folklore and just plain nonsense that’s been passed down for ages. Bob’s book helps shed some light on the subject, but as you can see, there’s still a lot of variability in finishing and it is entirely dependent on the nature of the object you’re finishing and how it will be used.

#23

Vaclav has done some great work…
…in the area of fabrics and epoxies, among other things. Keep in mind that these are the results of an extreme test. Unless you leave your paddles out exposed to the weather year-round, you won’t see the kind of degradation that he did for quite a while.



Whether to use epoxy and fiberglass should be a decision based on whether you need the reinforcement or not; it’s really not about finishing. Epoxy and glass are structural components, not just cosmetic coatings like finishing products. If you don’t need their structural properties, there is absolutely no point in using them.

#24

Billionaires and paddles
Exactly.



I called Phil and he said he was making a canoe for a billionaire in Connecticut. I told him that wasn’t me, but I did have $87.95 to splurge on a paddle.



Turns out he’s from Connecticut, too, and we had a great chat talking about paddling in the uber-magnificent Sparkelberry Swamp and rolling canoes with S-blades. He sent me his DVD, which is breathtaking.



What’s a mere $3,500 for an ancient wood paddle when you are buying a $130,000 ebony canoe to hang in the boathouse of your $30,000,000 yacht?

#25

Cheap.
He should have charged him much more . . . .





YoS

#26

WOW lots of good info
So here’s my 2cents. I often use a coat or two of Watco Danish oil on my recently completed paddles…but my favorite stick (which I made in Don Beale’s class at SSTIKS a few years ago) doesn’t have any finish at all. That said, it has acquired a “patina” especially in the loom-shoulder area. I think it is some kind of “natural” oil from my hands.

Many of my creations are in WRC and they have a certain amount of natural resins in them anyway. The white Pine, Spruce and other “white wood” sticks usually get the Watco treatment.

#27

Personal voodoo
So far, this is a pretty polite and informative thread, and I’ll only contribute my personal wood finish voodoo, a combination of study, experience, and refusal to admit what I did last time was actually a mistake.



My whitewater paddle is laminated wood, glass fiber/epoxy. Spar varnish on top of that. It works fine, doesn’t have to be babied, and it survive d a major overhaul and refinishing a few years ago.



My canoe poles live in a harsher environment, much more susceptible to crushing-type damage. They get a couple of coats of epoxy, applied (carefully) with a heat gun in the manner recommended by the Gougeon Brothers. About 18" of the working ends get epoxy+filler+graphite with the faith/assumption/design/hope that that’ll be less likely to wedge. The regular epoxy gets a couple of coats of spar varnish, steel wool to break the glaze, and old-fashioned x-country ski wax for grip.


#28

Tung Oil
Beale reccomends tung oil. You control how glossy it gets with the number of coats. I have two cedar gp’s from him and this is what I use. I figure Beale knows best, just look at the paddles he builds!

#29

A thought
on UV protection and discoloration. The tests cited and illustrated make a great point BUT, paddle exposure is generally quite limited compared to the test samples.



Most people use their paddles intermittently and store them under cover when not in use. Even when in use, part of the paddle is most always shaded ( or shadowed) or in the water. Even for those of us who use their paddles heavily, it would likely take multiple lifetimes to gain the same UV exposure as the cited test samples.



Marc Ornstein

Dogpaddle Canoe Works

Custom Paddles and Cedar Strip Canoes

#30

Beale vs. bnystrom; what tung?

– Last Updated: Aug-18-09 3:15 AM EST –

Beale's web page for solid paddles says he uses two coats of an unnamed oil over a coat of epoxy:

http://www.bealepaddles.com/solid.html

This conflicts with bnystrom's advice not to put epoxy under oil.

In addition, if Beale is using tung oil, I think it is important to know whether he is using pure tung, tung mixed with thinner, or tung mixed with varnish. We now know there are differences.

In contrast, Beale's web page for laminated paddles says he uses three coats of spar varnish over one coat of epoxy:

http://www.bealepaddles.com/laminate.html

So, fellow aficionados of voodoo and juju, why do you think he treats solid western red cedar differently from laminated red cedar? Maybe that accounts for the $150 price difference.

#31

Good thought
Bnystrom and Mornstein are surely correct to point out that those test panels have been continuously exposed to the weather for a year, whereas a paddle blade would not be so extremely exposed.



Especially the paddle blade of the Dogpaddle CEO, who favors palm rolls and in-water returns.



Those test panels do look like my unfortunate Old Town OTCA, and may provide interesting data on the quality and longevity of different epoxy products.