What is the consensus on polyurethane?

N

newbombturk

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Dec 12, 2015
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Hello,

New member here with a quick question about haft finishes. I joined Bladeforums with an enthusiastic interest in handmade knives and then I stumbled into the axe subforum. Long short, my first purchase wasn't a knife but a Plumb boys/half axe head in pretty good condition. I'd like to hang a new piece of hickory in 26" range and I'm completely content finishing with BLO but my mind wanders...

I have experience with TruOil, spar urethane, spar varnish, and wipe on polyurethane. I've read a lot about raw linseed oil, BLO, pure tung oil, wiping varnishes, 2 in one stains, alcohol based stains under a stain sealer and then under something like Minwax tung oil finish...my head is spinning.

Operating under the assumption that polyurethane is quite a bit more water repellent than BLO or tung, why don't more people finish their hafts with a satin poly? Blisters? Tradition?

Thanks for entertaining my question. Merry Christmas everyone.
 
Most of these are surface coatings. Freeze/thaw, natural swelling and shrinkage of wood, and UV from sunlight break these down or cause them to peel in fairly short order if you actually use the tool and don't store it in climate-controlled conditions. Oil finishes penetrate and never fully set or harden (ie they flex) and more can be rubbed in/on as needed. Stay away from surface coatings for protecting tool handles, unless they're wall hangers.
 
What 300six said. There are old hand tools that are fifty to a hundred years old that have their original handles in perfectly useable condition, and the only thing ever done to them was they were stored well.

Handle coatings might bring back an old handle that has been poorly stored short of being rotted, but for a handle in good shape they are nothing but a fashion trend.
 
Surface coatings are subject to abrasion and failure. It's best to have something that penetrates the wood. But if you want the nice surface finish you can add a couple coats of tung oil over the BLO.
 
The raw wood or wood lightly treated with a penetrating oil is also much easier on your hands. You'll find that with a lot of use, the polys and varnishes create major hot spots on your hands in comparison. Polyurethane just might be the worst in that regard.
 
I use wood handled tools a lot (canoe paddles among other things.) And an good oiled finish is more comfortable and much less prone to blistering the hands when used hard with moisture present.

The other advantage is that its much easier to repair, touch up, or refinish with oiled wood than with the other "harder" finishes. With oil there is no need to remove the old completely, or even at all if it was done right and not left thick and goopy on the surface to begin with. This is the reason I use a blend of tung and BLO on my natural wood floors. I can touch up and refinish high wear areas from the dogs etc, without having to sand down my whole floor. :)

oiled wood is heaven...
 
Rapt_up said:
I use wood handled tools a lot (canoe paddles among other things.) And an good oiled finish is more comfortable and much less prone to blistering the hands when used hard with moisture present.
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Interestingly enough the wonderful old gent that made my prized cherry paddle 37 years ago insisted on my using real Spar Varnish to finish it. Fine steel wool leaves the grip with a wonderfully smooth surface. I don't leave this out in the sun or rain (when it's not in use) but it has lived in an unheated shed for much of it's life and the finish has not cracked or crazed. Granted touch ups involve more than brushing on additional varnish but I really don't have any complaints at all and I would cheerfully use it on axe and tool handles that didn't get constant use and abuse.
Oils of course are much easier to come by, to work with, to reapply and are not a mere coating.
 
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I use urethane spar varnish, oil varnish and thinner. This creates a thin but flexible film with some UV resistance. One coat is almost indistinguishable from bare wood, and 2 is about all a tool handle needs. As 300 says, use extra fine steel wool or even burlap or a green scrub pad to smooth it once it has cured 48-72 hours, then either wax or leave as is. Apply extra heavy coats to end grain, as that is where moisture mostly gets in or out.
 
BG_Farmer said:
I use urethane spar varnish, oil varnish and thinner. This creates a thin but flexible film with some UV resistance. One coat is almost indistinguishable from bare wood, and 2 is about all a tool handle needs. As 300 says, use extra fine steel wool or even burlap or a green scrub pad to smooth it once it has cured 48-72 hours, then either wax or leave as is. Apply extra heavy coats to end grain, as that is where moisture mostly gets in or out.
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Traditional Spar Varnish should never be confused with synthetic (urethane) 'so-called Spar Vanish'. At the store you often cannot distinguish between the two unless you read the fine print side panel ingredients. Modern plastic polymers, so far, are not an equal substitute for the real thing.
You're going to pay more and it's going to be tougher to find but over the long term it's well worth it. Shelf life of genuine Spar Varnish has always been a major shortcoming but ever since I started keeping mine in a metal paint can at the back of the fridge it stays good for a considerably longer period (4-5 years and still counting!).
 
300Six said:
Traditional Spar Varnish should never be confused with synthetic (urethane) 'so-called Spar Vanish'. At the store you often cannot distinguish between the two unless you read the fine print side panel ingredients. Modern plastic polymers, so far, are not an equal substitute for the real thing.
You're going to pay more and it's going to be tougher to find but over the long term it's well worth it. Shelf life of genuine Spar Varnish has always been a major shortcoming but ever since I started keeping mine in a metal paint can at the back of the fridge it stays good for a considerably longer period (4-5 years and still counting!).
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It is not as good, but usable, cheap and widely available. The urethane spar varnish does have some other resins in addition to the urethane.
 
Interesting to see spar varnish come up. When I was a kid my grandfather gave me a short canoe paddle that read "McCloskey's Spar Varnish" and it had a glass smooth finish about 1/8" thick. Obviously it was an advertisement for Man O War but I paddled with it when my parents took me canoeing. It never showed any signs of wear and I certainly didn't take great care of it.

Additionally, before I had a family, I was very involved in all aspects of fly fishing including rod finishing. I developed quite a respect for rod makers that split, bound, wrapped, and finished their own bamboo rods. Real spar varnish is considered the gold standard traditional finish on bamboo however it is somewhat difficult to come by these days (possibly because of VOC restrictions?) so spar urethane is used more often now. The discussion always arose about spar alternatives and polyurethane would be brought up due to it's water resistance. That's what made me consider using it on a haft.

Heck, maybe I'll restore a couple heads, treat the hickory with different finishes and see how they wear. I have a quart of unopened Cabot spar varnish downstairs.

Thanks again everyone for their input. I appreciate it.
 
I have to say that if you're submerging then spar varnish or urethane is good. My canoe paddles have urethane on the blades and oiled shafts. :) hard wood absorbs less of everything so oiled is plenty protection if its kept in protected conditions. My paddles best paddles are hickory, maple and cherry. I make them myself, it let some tune them for best feel. :) I'm looking forward to doing this with my axe and hatchet handles.
 
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