Chainsaw milling experiments

This experiment started out with a large section of log from an ash tree that was cut down locally (it fell victim to the emerald ash borer, and I was allowed to take part of the trunk). I'm guessing the chunk weighed about 500 pounds. I had to split it into quarters just to be able to haul it home in my car.

I wanted to cut these into boards on my 18" bandsaw, but the quarter sections alone weighed 140 pounds (63 kg), too heavy to get onto my bandsaw. I could have used my bandsaw sawmill, but I didn't want to go get all the bits from my big country workshop to set up the mill in my backyard again. So I figured maybe I should use a chainsaw to cut the quarters into halves lengthwise, and then put it on my bandsaw.

The trouble with milling with a chainsaw is that chainsaws are not well suited for it. A chainsaw is designed mostly to cut across logs and branches, which is cutting across the grain.

But when milling logs into lumber, such as with an "Alaskan mill", the saw's teeth need to cut into the end grain, and that's much harder. Experimenting with a chisel, it's hardest to get chips out of the end grain.

But if the bar of the chainsaw is parallel to the grain, the teeth run with the grain, and it's much easier to get chips out. Also quite evident when trying this with a chisel.

I could cut the ends of the log that way, but I wouldn't be able to reach further than the length of the chainsaw bar. I figured the next best thing would be to cut through the log at as shallow a tilt as possible. But I needed some way to guide the chain saw to make a straight cut.

My first thought was to attach a piece of 2x4 to the log and cut along the side of it. But with the teeth a bit wider than the bar, I would just end up cutting the 2x4.

My next thought was to run the chainsaw itself along the 2x4, but the saw's housing is not quite parallel to the bar.

So I drilled two holes in the chainsaw bar (it's hard but just drillable), and made this piece of wood which provides a surface parallel to the bar.

With a straight 2x4 attached to the log, I started milling it. I start by making shallow cuts (with the bar nearly parallel to the log), then making more cuts angled further down.

This cut surprisingly fast. With my banged up old Stihl 026 (a relatively small chainsaw), I was able to cut the 5 '(1.5 meter) long log, 10" (25 cm) deep in just 2 1/2 minutes.

But the cut was not entirely smooth.

Cutting this way, the kerf tended to fill with sawdust. If the sawdust got in there tight enough, I literally had to cut it out, and sometimes the saw cut slightly off kerf in doing that.

Getting more practice, I realized it helped to make lots of passes, cutting very shallow. That way the sawdust doesn't accumulate in the kerf.

With practice, the cuts looked much better, and I was able to make one cut in under 2 1/2 minutes.

Some of the shavings, from the first cuts, are long and straight. These can jam up around the sprocket, though it wasn't too bad. But these long shavings are excellent kindling for a wood stove, so I let them dry in the sun and then saved them for the winter.

The milled blocks.

It was tempting to keep milling these into boards with the chainsaw, but that would be wasting a lot of wood because of the wide chainsaw kerf.

I ran each block across my 12" jointer to get two smooth straight faces. I handn't designed that jointer for pieces this heavy, but it stood up to the abuse ok.

I filmed the last part of the video as timelapses using my Raspberry Pi with camera module and my imgcomp software to only record while there was motion.

Then milled them on my 18" bandsaw. The biggest pieces just barely fit. I milled them with the same 1/2" blade, 3 TPI, that I use for everything on that saw.

When resawing, sometimes I hit a point where the blade lacks critical sharpness and I can't continue. (more on that here). This point can be very abrupt, and I hit it in the middle of cutting a board. I had to back it out and sharpen the blade with a Dremel. Sharpening itself only took 3 1/2 minutes. Cutting was much faster after that.

Running these heavy pieces of lumber over the jointer and the bandsaw was very tiring on the arms (maybe I'm just out of shape). So I finished up the last two big sections by cutting them into two squares with a skillsaw. I had to cut from both sides to get through it. I can always resaw those square sections into whatever I need when the time comes.

And here's the lumber. It will take a few years to dry.

I used to dry the wood by stacking it on the south side of my house, but I suspect this caused it to dry too fast initially, leading to cracking. So I intend to leave this wood in my shed in the shade for a few weeks.

They have been cutting down all the ash trees in Ottawa because of the emerald ash borer. I really like ash wood, so I was keen to save some of it before it's all gone.

I'm really happy with how well my chainsaw milling technique worked. But I tried the same thing with some silver maple and my "Poulan Pro" chainsaw (the kind you can buy at stores like The Home Depot), and the results were not as good. At some point the area around the sprocket got so clogged up with shavings that the chain couldn't run at all. Silver maple is much "stringier" than ash, which also caused some problems last time I milled some with my bandsaw mill. It could also be because of the smaller, narrower chain on the Poulan, or maybe that the Poulan chainsaw is just not as good as a Stihl. But for cross cuts, the Poulan works well enough.

There are also special ripping chainsaw chains which are slightly better at cutting into the end grain. I didn't need one for ths method of milling, but enough people have emailed me about ripping chains, I thought I should at least mention that I am aware of them. But I don't have one.

See also:

Milling a log on
the bandsaw (video)

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