Tuesday, August 26, 2014

Round two completed

The logs for round two of the cabin are completed. This was a good chance to fine tune the process of calculating, scribing and cutting the saddle notches to the correct depth so the tops of the logs for even numbered rounds will be at the same height. Looks easy enough, right? But when you think about it the logs are tapered and different diameters on the ends, maybe not.

The tool that makes it possible is the Log Scribe. A dividers with a point on one leg and Ink pencil on the other.

What makes it work are the two levels that keep the dividers in the correct planes while you move it along marking the line for the saddle notch and groove cuts. You keep your eyes on the levels, not the pencil! This takes some practice to get the hang of.

With the lines marked I like to chisel the line for a positive reference so as not to over cut it when using the axe or saw.

And if all goes well this is what you get. All four corners at a height of between 21" and 22" with a minimum 3" wide groove making contact with the log below it. When the EM Seal expands in the groove the joint will be air tight.

With the new school year starting this brings to mind the old saying about learning and it applies here for sure. "I hear it I forget. I see it I remember. I do it, I understand!" 

Monday, August 18, 2014

Scribing and fitting the first logs

I almost forgot how much work was involved in the "process".  Chop the saddle, position log, calculate rough notch, chop rough notch, scribe finish notch, saw edges, chop, re-sawing and fitting logs to build the walls. But it would all came back to me during the next eight hours it took me to do it!

The bottom logs were whoppers! I needed to add a block and tackle to my parbuckle to get them up onto the cabin base logs.

The logs needed to be positioned on the walls and then I could determine the gap difference between each of the logs and its mate. A rough notch would be made on each end to set the tops of the logs level.

With the rough notches cut and the tops level the final scribed distance can be set. This distance can be adjusted for each side of the cabin to keep opposite walls at the same height. Tricky!

After the log groove and notch is scribed they are cut like this with the chainsaw.

The axe can be used to split off a large portion of the wood that needs to be removed and provide clearance for the next chainsaw cut to remove the center wood.

The "vee" shape of the cut will need to be rounded out to form the concave to match the log it will sit on. This could all be done with an axe but some how I don't think I need to have that much fun!

After a bit of work with the 4.5" right angle grinder with the chainsaw blade on it the groove looks pretty good. My wife said it looked like I was making a dugout canoe. That reminded me of an Indian reenactment demonstration I once saw where they used heated rocks to char burn a log to actually make a dugout canoe!

Wood ashes are sprinkled on the top surface of the bottom log. When the top log is rolled over on top they will mark any surfaces of the groove that need to be cut deeper so the log notches fits tight.

A couple of tries and the fit is tight and good.

Do this just 38 more times and the cabin walls will be done. Now I remember just how much fun/work this is going to be!

Tuesday, August 12, 2014

Ginpole - poor man's crane

With the ridge and perlins removed and racked out of the way it is time to lay down the log trusses and take them off the cabin floor.

Normally the ginpole or "lifting stick" would be used to raise the truss but I thought this would work in reverse and be a nice test run for when I have to re-raise the trusses when the cabin walls are done.

Using the winch and a pulley in this setup I was able to eliminate the ginpole and simplify the process. From this exercise I have determined that for re-assembly the first truss will be raised using the ginpole and then the other two will be winched up like this. At least that's the plan.

Finished off the porch deck with some of the left over oak 2x6's salvaged from the Lamont barn cabin from two years ago.

Here the first round of logs with their blind dovetail joints re-assembled on the cabin floor it is finally time to get down to the business of cutting the logs for the cabin walls. So far so good!