Keeping dovetails clean when cutting with chainsaw.

[Joe Hillmann]

I am getting ready to start building my cabin and figured I should cut some practice dovetails.  

I was cutting them with my chainsaw and it was throwing bar oil all over the the side of the log that will be inside the cabin.   The oil caused all sorts of staining that I dont want inside my cabin.

Does anyone have any suggestions on how to prevent it?

I have considered;
Masking it with tape and paper.

Doing the cuts with no bar oil in the saw and accept it will damage the chain and bar.

Or switching to a clear mineral oil or vegetable oil for bar oil.

[Tom King]

I've had a little electric chainsaw I run the chain dry on for decades.  It just uses a cheap replacement Poulan type bar and chain.  Doing such cutting, it lasts a lot longer than you might think, and doesn't even stretch as fast as you might think.  You might even do your whole cabin with one bar and chain.

In this picture I'm carving out the termite eaten section in a support beam in a 1798 house.  I can't get oil in these houses and just consider the bar and chain sacrificial, but they will do a lot of work before done.

The saw is a Craftsman that I bought new in 1974.

[Tom King]

It's important to keep the chain sharp, tight, and to cut with a light hand.  If the chain is not working hard, it will last a lot longer and not get nearly as hot as if it was worked hard and dull.

[Joe Hillmann]

I just bought a electric chainsaw last week for at the sawmill.

I tried cutting a few dovetails with it with no oil.  It works but the chain is so narrow that it doesn't allow me to adjust the cut once the bar is half way into the wood.

On my gas saws the chain must be wider than the bar so I can kind of steer the cut if I start drifting away from the line.

[Tom King]

Yes, you have to start right to stay right.

[Tom King]

Here is that termite eaten structural T-post after I had spliced in dry treated wood.  No cutting was done on the old pieces other than with that little electric chainsaw.

Practice on some scrap first.


 

 

[Joe Hillmann]

The practice suggestion is good advice.  I have cut about 15 practice half dovetails in the last couple days.  They are getting much better than the first few I did.

[jake pogg]

The practice suggestion is good advice.  I have cut about 15 practice half dovetails in the last couple days.  They are getting much better than the first few I did.

If you start the cut at one of the corners,while keeping two of your converging lines in sight at a time,the cut shouldn't need that much steering.
Are you getting as precise of a cut as you'd like,just using a chainsaw?
I never managed that myself. On a recent(half-dovetail) place i ended up using a wormdrive around the circumference,then a slick to finish the removal and clean up the surface overall.
(Which i concaved slightly in hopes of a tighter fit).
In retrospect i wish i built and used a jig,as laying out with a square and/or pattern was often not Quite good enough for alignment with the opposite tenon,or the adjoining ones either.

[Joe Hillmann]

After the chain saw I come back in and clean it up a bit with a jack plane on the flats and a chisel in the corners.

I thought of cutting as much as possible with a skill saw but with all the angles involved it dint seem like that would work.  I have also though of just doing it with a hand saw.

From what I understand the halfdovetail jigs need very consistent logs to work.  And my logs are not consistent at all.

[Stephen1]

On certain saws there is an adjustment for the oil. I turned mine way down when I was doing my cabin. 1 tank of oil would last 3 tanks of fuel. Lots of Timber Framing is done by hand saw. 

[Joe Hillmann]

I gave up on the dovetails and decided to go with butt and pass.

I was not sure how to deal with dovetails on my full length logs that twisted while drying.  And butt and pass is easier to do.

[rjwoelk]

Just curious did your logs twist clock wise or counter clockwise pictures?

[Joe Hillmann]

Looking at the end of the logs the mostly twisted counterclockwise  as it goes towards the other end.  

But they also bowed up, down, in and out.

I dont want to post close up pictures because nothing is coming out as nice as I had planned.  Right now I am planing on chinking covering all of my mistakes.





All summer it was a drought.  We maybe had 3 inches of rain all summer.  In the week since I uncovered my log pile we have had 5 inches of rain.  So mold is starting to grow, the logs are swelling/cracking and I am having to deal with mud.  My hope is once they are under cover they will dry level and i can sand off the worst of the staining.