Finishing koa

Bill DeShivs

Bill DeShivs

Knifemaker / Craftsman / Service Provider
Joined
Jun 6, 2000
Messages
12,639
I'm completing a knife with customer-supplied koa wood.
Spray lacquer rolls off when sanding and doesn't seem to fill the grain.
I have tried sanding and buffing the wood, but it picks up too much compound.
I resanded and used my old standby for gun stocks-Arrow Wood Refinisher-an oil-type finish.
The oil just pools up and doesn't dry.
Unless someone has a simple method, I guess I'll just steel wool it and wax it.
Thanks.
 
Bill

Is it stabilized or not?
If not, then use danish oil and wet sand it in, let dry, and wipe off across grain. That will fill pores- may take a time or 2. The oil finish, making sure to let each coat dry well. you can sand Koa up to 2000 if you want "shiny" finish.

If it's stabilized, most guys just buff after sanding to 1500/2000....but you can use oil here too if you want it "liquid-shiny"

Bill
 
I've done one piece of koa that I went through multiple failed attempts on (unstabilized). What in the end worked was the sand with danish oil as the lubricant method. I did three rounds of that, then a last oil and wait. For the last step I hand buffed with steel wool after things dried which is when it finally looked like something.
 
I've often used spar varnish (NOT spar urethane, real varnish. It will list Chinaberry oil and drying agents on the label rather than polyurethane. Checking the fine print is important) for difficult to finish woods. It works fairly similar to tru oil, but seems a bit less picky on not curing on oily woods.
I'll wipe on a little with my finger, just enough to get it all wet. Then pretty well right away wipe it all off with a cloth. There is such a small amount left behind that even on the oiliest wood it'll still cure. Repeat that every 4-5 hours until you have a decent finish built up. Then run it down with 600-800 grit sandpaper to smooth everything out, and give it a quick buffing on loose wheels. First with lustre bar, then pure carnauba wax.

Although if the wood is that resistant to taking finish, just buffing it a couple times with the carnauba wax would likely be a sufficient finish
 
I just did one with unstabilized koa. I used tru-oil and am very happy with it. Had no problems with drying.
 
With un-stabilized Koa I've used Tru-Oil with success. Thin the first coat and sand it in with something like 320 grit, let dry, then another light sanding to get the rough off, then several coats of tru-oil, wipe on, let sit a few minutes, then wipe off, let dry a couple or 3 hrs, then repeat for several coats. Winds up with a nice finish and seals pores pretty good. If there are many open pores, perhaps use CA glue as first coat to sand in CA/wood dust to fill pores, then finish with Tru-Oil.
 
billf said:
Bill

Is it stabilized or not?
If not, then use danish oil and wet sand it in, let dry, and wipe off across grain. That will fill pores- may take a time or 2. The oil finish, making sure to let each coat dry well. you can sand Koa up to 2000 if you want "shiny" finish.

If it's stabilized, most guys just buff after sanding to 1500/2000....but you can use oil here too if you want it "liquid-shiny"

Bill
Click to expand...

Bill's got exactly right. I love a nice hand finished oil finish on unstabilized koa. No machine buffing required.
 
I agree with Bill about the Danish Oil and John about not machine buffing.
Just my personal preference but works well for both natural and stabilized Koa.
 
One thing that can help is to wipe down the wood well with denatured alcohol just before the first coat of oil finish is applied.
Sand in the oil finish and let dry for a while and wipe off any excess. Let it cure overnight and repeat the wet sanding and dry cycles as many times as you wish.
 
I think the lacquer actually did fill the pores, and that's why the oil wasn't soaking in well.
Got it done and the customer likes it.
Thanks!IMG_4706.JPG
 
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