Polyurethane

bubba-san

bubba-san

Well-Known Member
Is poly a suitable coating for an outdoor type knife handle ? or would epoxy be a better choice ?? I used some on some outdoor furniture and the poly turned white and started peeling !!
 
To be honest, I don't l ike the idea of either one for esthetic reasons; too glossy and arificial looking. Finishes like boiled linseed oil have worked for years with minimal upkeep, which would still be required with a poly or epoxy finish. Plus the hardening oils, boiled linseed oil being one, penitrate more deeply. There is also the choice of woods; your heavy, oily woods hold up to the elements just fine on their own. If I wanted something to be impervious to the elements with no maintenance I'd go with professionally stabilised wood or something like Dymondwood, which is essentially the same thing.

Doug Lester
 
Thanks Doug , I agree with you , I have a customer who put poly over stabilised wood that also had been treated with tung oil. I think it will peel off .?
 
Poly the way it's usually used on furniture and such, is too glossy and sometimes sticky for my taste. I never tried it on a knife handle, but I suspect if you sanded it down to where it felt and looked right, you wouldn't have much of it left to protect the wood. I'd also worry about the peeling and discoloration like you said.

Much better off with the "old-fashioned" oils or modern stabilized wood, in my opinion.
 
Bubba,
If your friend wants urethane then use spar urethane.
It's made for outdoor use and is water resistant and has UV protection.
I use it on furniture pieces that I have made that have woods that will change color when exposed to direct sunlight or when oils will change the color. Will not turn white or loose.

But Caution, it won't give that warm look to the wood that say the poly or the oils do, it's clear. So don't think that " this is going to look good when I get the finish on the handle" It's going to look the same, color and warmth, just finished.
 
Maybe your friend bought a big drum of it and just wants to use it up :D Who knows, sometimes folks get stuck on one product and want to use it for everything.

I should try the spar urethane though, I forgot all about that. Might be nice for a basic traditional-looking knife. Deltashooter, how would you compare it to several hand-rubbed coats of Danish oil for durability?
 
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Hey James I’m for one glad to see you back.
It’s hard for me to say because I’ve never used it on a knife handle, Yet:les:
But I have it on a bookcase/plant stand that’s in our kitchen, oak trimmed in purple heart, that gets a lot of use and shows no ware or water rings/stains, or changing of color.
I will be trying it in my vacuum jar as a stabilizer for some oak burl that I cut a couple of years ago. I’ve used tung oil in it with great results.
 
James Terrio said:
...how would you compare it to several hand-rubbed coats of Danish oil for durability?
Click to expand...

I have used spar urethane before- I've probably sprayed well over a thousand gallons of it in a previous (work) life.
Comparing to Danish oil, proper application should result in reduced maintenance and better resistance to elements.

Looks, etc. are always subjective. Just have to get some and try it out.

Deltashooter is correct in post #6. The wood will look the same after finishing as before finishing. Spar urethane does not add "warmth", "depth", etc. But it does provide great protection. If you like the look of the wood before, you'll like it after.
 
I recently tried some outdoor spar urethane on a spalted Maple bowie block in my home made vacuum stabilizing rig.
I got about 2/3 penetration by adding some mineral spirits. The resulting block turned out pretty good.
Next time I'll drill my tang hole and shape my handle first to get complete saturation. Pre-shaping will also
save on belts which gummed up very quickly on the spar treated wood. A coat of thin CA added a nice finish.
 
I think for the most part these are surface treatments and will not provide very much protection at all. Even guys that boil the "oils" before dunking dont get much more than surface. Then you have to consider the density of the wood. If your using anything thats not really soft and porous you will have a hard time getting 100% penetration even under vac. Thats why the pros use thousands of pounds of pressure and heat activated curing methods. Its easier to get away with movement etc on a stick tang, but more noticeable on a full tang. -L
 
Larry, I understand, thanks more stating that clearly. Personally I very much prefer professionally-stabilized woods* for various reasons, but every now and then someone wants a more "old-school" type handle that ages a bit with use and so forth. Danish oil, the urethanes, etc etc probably differ only by a few percentage points in terms of toughness. It's fun to try different ones, though :)

*no offense to guys who do their own, but for me I trust the folks who do it for a living with serious pro equipment. I've seen posts on everything from mason jars in a hot-water bath to bicycle pumps used to "stabilize" wood... have fun! I'll let K&G or WSSI do it for me and leave the guesswork to others. Just my $.02
 
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