Building Our Bush Cabin – Part 4 – Chainsaw Milling a Log

It has been a while since I’ve posted anything on the cabin progress, so first up a quick update:

  1. roofing and guttering is on
  2. flooring is down
  3. some walls have external cladding

The dimensional timber I’ve used so far I have milled with the help of a friend and neighbour who owns a portable mill (see part two). While that has been awesome and saved me thousands of dollars, I like to be as self-reliant as possible. I can’t afford a proper portable mill at this time so alternatives had to be researched. I ended up purchasing the Logosol Timberjig chainsaw mill attachment. This is a simple device that attaches to your existing chainsaw allowing you to make quite precise ripping cuts on a log. While more expensive than many other more basic chainsaw mill attachments (especially here in Australia where they retail for $300) this seemed to fit the bill for accuracy, ease of use and expandability. While it is no replacement for a full blown portable mill as far as sheer production goes it works well when you only need smaller quantities at a time and is many magnitudes cheaper.

Now for those who’ve never done it, here’s a run down on how to mill the log.

First up select a good sized tree with a good section of straight trunk. I found a nice stringy bark with about 7 metres of usable trunk ranging from about 50cm to 40cm in diameter. Fall the tree, taking all appropriate safety precautions (felling trees is extremely dangerous), then cut the crown away from the trunk and if required cut the trunk into the sections at the lengths you require. Move your trunk section away from the rest of the tree into a clear working area (I just used a crow bar to roll the trunk aside).

Once your log is clear of the rest of the tree you need to remove the bark. To do this score X marks down the length of the log with an axe then use a pry bar or crow bar to strip out the scored bark, as seen below:

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Now starting at one end, take your crow bar or pry bar and slide the point between the bark and the wood, pushing firmly while also lifting up to prise the bark away. Move along the length of the log doing this and the bark should peel away.

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Once one side is done repeat the process on the other side until the bark is completely free from the log.

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The inside surface of the bark will be extremely slippery, so taking care not to slip, roll the log off the bark onto a more suitable working surface.

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Now chock the log so it wont roll around and screw the Timberjig guide rail to the side of the log so we can make our first cut. If, like me, you only bought the Timberjig and not any rails then you will have to make up a timber guide rail as per the instructions that come with the Timberjig.

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Once the rail is in place it’s time to make some noise. But before you do here’s a quick check list of items you should have:

  1. hearing protection (this is as extremely noisy job)
  2. safety glasses (there is a LOT of fine sawdust flying around)
  3. face mask (I didn’t use one, but I will next time due to the fine sawdust produced)
  4. safety chaps (I don’t have any as yet but will be looking to get a pair ASAP)
  5. sharp ripping chain for your saw (this is like a regular chain but the teeth are cut at 10 degrees rather than 30)
  6. 2-stroke fuel and bar oil (you will use lot of both)

Once your safety gear is on and your saw is fuelled up, oiled up and ready to go, start ripping!

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My saw is a Dolmar 111 and although a fantastic saw, at 56cc (I think) it is a little underpowered for ripping Aussie hardwoods, but it gets there in the end. To make sure it is cutting as efficiently as possible and avoid applying undue pressure on the bar I sharpen the chain after each run.

Once you have the first cut done, unscrew the guide rail and screw it onto the cut face and roll the log so you can make your next cut which will be perpendicular to the first. Once the second cut is done remove the guide rail. Your log should now have two square faces as such:

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From here the Timberjig comes into it’s own as you no longer need the guide rail but rather you use the two perpendicular flat faces as guides on the specially designed Timberjig. You can of course adjust the depth of each cut.

Once you have your log converted into slabs you can continue to process them into dimensional timber with the saw and Timberjig or, as I did, use a circular saw to rip the slabs to size.

I processed two logs, one about 3m (as in photos above) and the other about 4m long into ten joists at 100mm x 50mm x 2700mm and four bearers at 250mm x 50mm x 4000mm. All up, including felling, milling and ripping to size this probably took me the equivalent of two eight hour working days. Hopefully I’ll get faster with practice but I still think that is pretty good considering to buy the timber would have cost me well over $1000, at least.

Oh and by the way, we went from tree to this (with some left overs and plenty of firewood to boot):

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(Yes it will be our bathroom, yes it’s going to have walls, yes it’s kinda nice without em though!)

PS for those interested in parts 1 – 3 of Building Our Bush Cabin here’s some links:

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