Drying a mantle

[True North]

I just cut a mantle for someone out of N.W. Cedar.  It is 12" x 9" x 8' with a live edge on the front. It came out great, but I am wondering about drying it. I know someone with a high volume kiln and I can bring it there, but was wondering if I could just put it in my outdoor furnace shed. I just am not sure if not controlling the humidity correctly could cause the beam to crack. Also, how long should it dry for?

[beenthere]

Did the customer order it "dry" ?  if so, to what mc% ?

Is it at final dimension now, or will be trimmed to final dimension when dry?

[True North]

They wanted it dried, did not indicate a M.C. (they don't really know). The mantle is cut at 8" now, but will be cut down to just over 6' when dried.

[Jeff]

I've got a live edge northern white cedar mantle above my fireplace and it was put up there probably less then a month after it was a tree. It also has cedar corners that were trees lestt then a week before installed.  This was about 6? years ago. I put a relieve cut in the bottom of the mantle so it had a place to check, and the corners have cut outs in the back for the same purpose. I'll go take a couple quick photos so you can see how they are holding up.  I also built a log bed this last fall and put it together as parts were found in the woods. Parts of the bed were finished while other parts were still trees.

N.W. Cedar dries quick enough without a kiln in my opinion. I think speeding the process up with a kiln might not be all that beneficial. 

[Jeff]

Its not as thick as yours, but its right out of the center of the log where you would expect it to spit apart.  Its 3.5" thick by 14" wide.  THe one end have a check in the bottom and its following the relief cut I had put in it before it was installed.
  Plan your drying defects.

[True North]

Thanks, Jeff. That really helps! So did you just make a really shallow cut with a skill saw?

[Jeff]

Yes on the skill saw, but I made about 4 passes to get a nice wide kerf. . I kept the cut back from the ends about 6 inches or so.  I'd say the cut was 1.5 to 2 inches deep.

The corners you see, are missing about a quarter of the log. Its the same way I did the corners on our house. Another project where we used a lot of green cedar logs.

Here is a lengthy thread about that documenting on how we turned our house into what looks like  a cedar log home several years ago.
http://www.forestryforum.com/board/index.php/topic,7218.0.html

[beenthere]

..............

Here is a lengthy thread about that documenting on how we turned out house into what looks like  a cedar log home several years ago.

I think, no....I know! that Jeff meant to type "our" house. 

[Jeff]

WHaddaya talking bout?

[red oaks lumber]

jeff,
 thats one danG nice looking out house............

[tmroper]

Great looking mantle Jeff!!!  would you post the pics of the bed.

[Jeff]

Here ya go. You can watch me build it.

http://www.forestryforum.com/board/index.php/topic,39063.0.html

[beenthere]

Any squeaks yet? 

[logloper]

Just reading along here and have a question. What is a "relief cut" and why is it used? How is the best way to do it? Thanks

[Jeff]

My definition of a relief cut is this. The wood is going to dry and shrink. When it does, its going  to crack to relieve the stress that is inevitably going to build. I just figure its going to happen. So what I do, is I try to outsmart it by creating the crack right at the beginning so there is already a point for the stress to escape. By doing that, I can try to do it in a place where it will matter the least. In the case of the mantle, on the bottom side.

On the bed posts, I did not make relief cuts, because its a rustic bed, and as massive as it is, I just let it dry naturally and hoped for the best.  Its got a few cracks in it, but not bad, and I can almost guarantee its as dry now as it will ever get after being in this very dry house all winter. 

[True North]

The pictures of your house are great, Jeff.  Thanks for the advice. I was wondering, how did you cut out 1/4 of the logs for the corners? I was looking at making some furniture, and was wondering how to do it for that, but now I want log corners on my house to!!

[Jeff]

First I put the log up on saw horses and decided which part of the log was the best area to remove.  I then used a level to create vehicle lines on each end of the log, then uses a framing square to layout the 90° to be removed.  We then used a chalk line to snap from one end of the log to the other to get the two straight layout lines along the length as straight as we could. Because of the undulations of the log, the line will be hit and miss, but you get enough to be able to follow it straight.

Once we had the lines laid out, we used a skill saw to score the lines as deep and as straight as possible.  I then set the blade at a 45, move in from the line about an inch, and cut again, taking a "V" out the length of the log. Do this for both cuts.  Now comes the chainsaw.  You have that straight line, and with the "V" of wood taken out, you can now get in there with the chainsaw to remove the rest of the wood without muffing up your nice straight lines.  Its actually better if you remove too much wood, because the corner will fit right tight to the corner of the house that way.

[True North]

Thanks, Jeff. That makes complete sense. How's the snow down there? We are finally getting some today.

[Jeff]

Just Flurries.

Don't get too much. I have to come up to the Soo next week!

[Dalden]

I have a 5.5" x 10" x 6'  ash live front almost done - I left it outside for three weeks in the shade - rain or not.  Then into the garage, on the concrete floor for 3 week covered.  I think the concrete kind of helps to keep the outside a little moist releiving stress while it dries.  Thought it was OK ,  then I cut out the back for the hanging board (I hang them on 2xs cut at a 45 so that one mounted to the wall pulls the other into the wall -the one mounted into the mantle has enlogated holes for the mounting lags -that way it can move and not crack).  Well when I was removing the wood out of the back about 1.75 in. deep, I hit a pith check running the length of the log - instant crack about two inches in and two feet long.  Fixed with a little poly glue (or a lot maybe) .  Set the whole thing on the bench for another 3 weeks - then into the house for a week.  No more appreciable movement or cracking.  I think I should have pulled that last step before I cut the releif for the back...  might have saved me some work.  I don't know how your planning to hang it - but if your gonna releive the back look at the end grain for those nast pith checks - If it aint dry when you cut into it if there is any stress it'll let go and change the top or bottom right above the releived area.