Birch oil/tar handle finish

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GrenfellsBrutalForge

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May 23, 2016
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Was wondering if anyone has ever used birch oil/ birch tar to finish their wooden knife handles.
How durable was it? How did it look? How do you apply it?
I'm thinking about trying it out on some wild cherry which is really light in colour. Id like it to be a lot darker and I'm wondering if this stuff will do that. Is it rubbed in to the wood, brushed on? How many coats and how long in between coats?
There's lots of birch around here and I'm sure I can make the stuff. Might be a cheap option if it's any good
 
Give it a try and let us know how it worked out. Some here will be pleased to hear of your results.
Frank
 
Hmmm, that's an interesting idea... I'd love to hear how it works out for you. Lots of birch around here too.
 
Cherry darkens substantially with exposure to sunlight over time. For woodworking I have rubbed in a mixture of genuine turpentine and BLO into cherry and set it in a sunny window and it darkens up nicely over a few weeks...
 
There was a technique for darkening with Linseed oil, explained in the "williamsburg gunsmith" video on youtube. Pretty slick for mid 1700's technology.
 
I use BLO quite a bit, I like the finish you can achieve and the way it darkens up the piece. It's also easy to do touch ups on damaged areas. It doesn't however provide much protection against moisture and can actually invite the growth of mildew in certain conditions. Birch oil is supposed to be anti bacterial, anti fungal, sheds water, darkens wood and can be touched up easily.
If I can find the time, and some appropriate containers, I'll try to make some this weekend
 
I'm hoping someone who has used it will let us know how to go about applying it. Getting short on time for experiments, was hoping to use it on the handle of the knife I'm making for my father in law for Father's Day. He used to use it on his traps but I don't really want to ask him about it because it's a surprise. He would have used it more as a preservative anyway, I'm trying to use it as a finish
 
Yesterday I went about making some birch tar. After distilling a gallon of birch bark, this is how much I ended up with in a pint can

I used a piece of white birch as a test. Rubbed it in with my finger, and after about 20 minutes wiped the excess off with a cloth. Sanded to 120g before applying. The top of the piece is uncoated. After the first coat:

At this point it darkened the wood quite a bit. The colour is more significant on the end grain

Looks promising so far. It's supposed to darken further if left in the sun, like linseed. I'm going to apply more coats and see how it turns out
 
I did this a few years back to some rifle stocks using pine tar. It's a nice look (and smells smoky too). The issue is the tars don't give a smooth even coloring. I was doing two stocks trying to match a look like Finnish WW2 rifles. The first application goes on thick and you want to leave it on to dry well then sand lightly (unless you want to even out the coloring). For the rifles I wanted the varied shadings.
 
I followed instructions from a guy who restored rifle stocks. Now that I recall more detail, the process was to keep it wet for a day. So every few hours I went into the garage and gave it another coat. This is not a fine finish or worry about brush strokes or lines. It's just to keep it wet so the wood absorbs the finish. After that I let it dry for 2 or 3 days. Then I did a light sanding, then final wipe and polish with a boiled linseed oil and beeswax mix. The 3 days is mostly because I wait until Saturday and because in Florida the humidity makes drying take longer. Usually 24 hrs is fine but humidity and the type of wood will vary that.
 
IIRC, the Finnish folks do Puukko handles by soaking in a jar of pine tar or birch tar for a long time (weeks to months). They also soak them for months in boiled linseed oil.
Once removed, the excess is wiped off and the knife is hung up to dry for a long time (again, weeks to months). It is then lightly sanded and buffed with a cotton cloth.

The only photo I remember seeing was they took a tall canning jar and lid and used the knife blade to punch a thin slot in the center of the lid. The knife was inserted through the lid so it hung inside the jar of tar/oil. Wax was applied around the blade to seal the slit, and the jar was set on a shelf with a date written on the jar.
 
i bet the soaking for weeks or months really makes for an excellent finish. Unfortunately I would need about 10 gallons of compressed bark to get enough to do a finish in this way. I'm really strongly considering it. For now I'm experimenting with what I have. The Father's Day knife didn't get finished with this stuff as I didn't know how long it will take to fully dry, and I'm not sure how long the smell stays on it. I like the smell myself, but my missus thinks it stinks.
I used it to treat the wood for the San Mai Bowie I'm working on. On Monday I coated it and left it in the sun until it started to look dry and then coated it again. After doing this 4 times it didn't seem to be absorbing any more so I left it overnight and the next morning it seemed dry. Gave it a sanding with 1000g paper gave it another coat yesterday and left it in the sun. This morning I sanded with 1500g and coated again.
Here's a picture of where I am now. The wood is wild cherry. Block on the right is the original colour
 
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