DIY Wasters: Linseed Oil vs. Polyurethane

[David_Knight]

My father is a retired golf pro and used to refinish high-end golf clubs. I was at his shop today working on my zweihander waster (which is turning out great... will post pics when finished) and he suggested that instead of treating the wasters I make with boiled linseed oil (as I have been doing), I should instead apply about 20 brush coats of polyurethane. He said the key is to dilute the urethane so it is easily absorbed, then apply two coats a day for a week or so until it has penetrated about 1/8th" into the wood. The end result is a glassy coat that absolutely will not crack (he proceeded to explain the physics of a wooden driver connecting with a golf ball at 200 MPH and showed me several well-used clubs that showed no signs of damage as proof).

Has anyone expiramented with polyurethane on their homemade wasters?

[JeffGentry]

Boy that sound's like a good idea was kind of wondering about that myself i have made 3 waster's out of oak. I am discovering alot of little crack's on the edge, from swinging them fairly hard against other waster's, what is he using to dillute the urethane denateured alchol, or paint (laquer) thiner?

[David_Knight]

He said lacquer thinner should work (the polyurethane should have that info on the label). In theory I don't see why it wouldn't work... but I'm hesitant to use this zweihander waster as a guinea pig since its the first one I've really taken my time on.

[JeffGentry]

well like i said i have been making my waster's out of oak so when i finish the one i am working on i'll try it my waster's are much cheaper so i'll let you know how it work's.

[James_Knowles]

If you try this, keep us up to date.

Off hand I'm a bit sceptical about the functional equivalence between a tiny golf club head and a big waster.

• The waster will flex in ways that a golf club head just won't.
• The basic physics of striking a stationary small-mass elastic ball vs. a sparring partner's fast-moving large-mass inelastic waster are completely different. Specifically:
• The ball has small mass.
• The ball is elastic.
• The ball has zero inertia.
• The ball is designed to optimize transfer of kinetic energy.
• The waster has large mass.
• The waster is comparatively inelastic.
• The waster has beaucoup intertia.
• The waster will take transferred energy into flexing, point distortion, and vibration.
• The thing that the waster has in its favour is that normally one is making deflection type of strikes. This will reduce a lot of the energy transferred into the waster's structure.
  

I'm also curious to know whether the polyurethane alters the winding characteristics of the waster. Is it sticker? Slicker?

How does the polyurethane take damage? I certainly have a hard time believing it's nigh indestructible. Does it shatter? Dent? How easy is it to repair damage? How does it sand?

[James_Knowles]

Not too long ago I asked about what BLO (boiled linseed oil) &c. do to wood on a woodworking.com forum. I can't vouch for accuracy.

Actually drying oils do not harden such as one gets hardness from shellac or lacquer, of from polyurethane for that matter. They do add some resillience to the wood which allows the dents to bounce back out. They do add a little in the way of water resistance, but they will not hold up to being wet for an extended period of time. The ease of fixing blemishes in an oil finish is its major benefit. I use it under a filming finish to highlight the grain. Keeping a good coat of oil also help preserve the wood.

This guy claims to have made a number of EMA sparring weapons. I don't know how accurate it is, but FWIW....

Such a thing - nunchaku, bokken, tonfa, bo, whatever... can certainly benefit from BLO treatment. The oil strengthens the wood fibers & bonds them more tightly together than they'd be naturally. It fills, to some degree depending upon the viscosity of the oil (better penetration if the oil has been thinned) the cells which are now otherwise empty - having at one time been full of water - and helps keep those cells (via hydraulic pressure) from easily crushing.

Further, it seals the wood to some degree and helps prevent the speedy oxidation & degradation of that wood.

It won't, though, make (or keep) the wood "flexible". If the wood ain't flexible when ya start, the oil ain't gonna' help... and if ya start with flexible wood it won't become rigid just 'cause no linseed was added to it. It DOES keep that wood resilient, though.

If (WHEN!) ya get dings, ya might try ironing 'em out instead of sanding. Use an ordinary steam iron, or a dry iron & a moist (not wet) washcloth or handkerchief (Remember those? How long's it been since ya saw one?). It takes a surprisingly short time for the steam to pop a dent right back out.

[James_Knowles]

Oak's kind of brittle compared to other woods like hickory. Personally I'm not a big fan of using oak.

[David_Knight]

The polyurethane will dent, but not crack. He demonstrated this by whacking an old driver with a metal bar.. the finishing dented a little, but the wood itself was untouched because it is buffered by 1/8" of polyurethane. Apparently the finish isn't difficult to strip down and repair, but I don't know the specifics of how to do so.

As for polyurethane affecting binds by making it stickier... I'm not sure.

I know that Kali sticks are usually coated with polyurethane or lacquer, as are many EMA staffs and such.

All I care about is whether or not it will strengthen my waster. I don't expect the finish to stay perfect, but if diluted polyurethane does indeed penetrate 1/8" into the wood, forming a non-cracking "shell", I'm all for it.

Oh, BTW, the diluted polyurethane should only be used until the wood will not absorb it anymore (6-10 coats). Once you reach that point, apply another 6-10 coats of regular polyurethane.

[JeffGentry]

well i still haven't tried the thin polyurethane yet but i have been modifying by design and trrying another wood, the oak i am discovering is very touchy it seem's when i sand the edge's if the grain end's there when i use if it dent's on the grain it will raise the grain i have to sand that down so and the it become's wavy. i think it is because the grain is so tight and you have alot of little end's. I'll will get to it though.

[Jared L. Cass]

Hi David! What's your dad's "recipe'"? How many parts lacquer thinner to how many parts polyurethane?

I'm going to give this a try as I just made a new waster after my old faithful died last Friday.

Thanks,

Jared L. Cass, ARMA Associate, Wisconsin

[Jeff Hansen]

Hi,as a professional woodworker as well as arma enthusiast I think I'm qualified to chime in on this one. The reason oak sucks for wasters is that if you cut a thin slice across the grain you will see that the fibers between the grain are hollow giving it a honeycomb effect. With impact,as with a waster, those spaces are compressed leaving a substantial dent. Then it peels up and you get some wicked splinters, not to mention what it does to the overall stength of the piece.

My first waster was oak, I think it lasted all of 3 or 4 months. My current waster is maple, still going stong after about a year. I've sanded the dings out a couple of times, but that's it. From what I've seen hickory is best, but it sucks to work with. the key, no matter what wood you choose, is to find a piece of lumber with the grain running as straight as possible through both dimensions.

I can't wait to hear some results on the thinned poly, it sounds promising. As for the finish affecting winding, if it's sticky, just give the last coat a good sanding.

Regards,
Jeff Hansen
Provo,UT

[David_Knight]

He doesn't have a specific formula. Use a test strip and keep thinning the poly until it clearly soaks in.

I made the mistake of using a 50/50 poly/thinner mix on my zweihander without testing it first, and it was a little too thick, so I'm stripping it off and will try again. 25/75 seems to be about right.

I used to make EMA equipment out of bamboo (it grows wild down here) and coat with poly. The stickiness goes away if you let it dry and wet-sand a little with an ultra-fine grit. Smooth as glass.

[David_Knight]

After approx. 10 coats of poly (diluted), wet-sanding, and another 6 coats (undiluted), my zweihander is done. I had originally pegged and glued the 2" ball pommel in place, but it came undone at an ARMA SoFL session last week so I screwed it in using a double-threaded anchor bolt.




A solid, hard strike against another waster will leave slight marks in the thick polyurethane coating, but the wood underneath isn't even touched. No cracks or splinters. All in all it has performed well thus far. I will report back next time I have a chance to use it in some waster-on-waster drills.

[David_Knight]

[color="red"]UPDATE[/color]

I'm very happy to report that the thinned poly coating has been a tremendous success. After finshing the zweihander in June, I made a longsword and one-hander out of cheap red oak and treated both with a 1:3 mix of clear polyurethane and lacquer thinner, respectively.

I've since been training with intent every weekend (and even attended the 2-day ARMA Florida gathering in Orlando) with absolutely no damage to the wasters. While an untreated (or boiled linseed oiled) oak waster easily dents and splinters, my poly-coated wasters perform as well as commercial ones made of hickory.

After some expiramentation, I've found that the key is to use 25% polyurethane 75% lacquer thinner, and keep applying it until the wood won't absord anymore.

Once the wood has been treated, you have two options:

1. The first time around, I applied several topcoats of undiluted poly to my zweihander, giving it a very smooth, glass-like finish about 1/8" thick. The drawback to this is that such a thick topcoat is slightly malleable and gives a little when struck, leaving minor dents. It also has a somewhat "soft" feel during impact.

2. For my two workhorse wasters, I used aerosol polyurethane, which yielded a much thinner, harder overcoat. I like the way these came out better than the zweihander because they don't have that thick, cushion-like coat - they feel as hard as regular wood, and repeated strikes against wasters and bucklers have left no indentations to speak of.

I definitely recommend the latter option. Very, very effective, and extremely inexpensive. I made two durable wasters for under $20 in supplies.

[Brian Hunt]

Cool,

I may have to try that with a hickory waster and see what the end results are.

Brian Hunt
GFS