Drying Old Log Cabin Logs For Mantel

[jkiesel]

I have a question that kinda falls into a couple areas so not sure where it will be best.

I have recently torn down an old log cabin that was built in the 50s and am replacing it with a new build. The cabin had a collapsed roof and many many other issues so I was unable to save it. We kept some of the logs from the cabin and I was thinking about making a fireplace mantel out of one. 

Given the logs have been exposed to the environment (Pacific NW) for almost 70 years and the cabin was not well kept, should I fully dry out the log prior to milling or should I mill it now and hope it will dry out over time and not check and crack?

At a minimum, 2 of the 4 sides and both ends would be cut but probably going to end up with 3 sides (top, bottom, back) trimmed off leaving about 8" x 6" x 72".

Really concerned about cutting it to size, installing it, and then having it fall apart or crack and I have to rip everything down or the wood just won't be able to stand the constant hot temps from the fireplace.

[samandothers]

Welcome to the Forum.

I have not done this, but an approach would be to cut what you want a little over sized.  Then have it dried.  It may move or check some.  Also, this would help kill any bugs in it.  Then cut to the finished size.  It may still check some but I would think not much.

Hopefully some smart folk will come a long and give you some good feed back. 

[jkiesel]

Thanks!

The log will end up being about 7.5" x 5.5" x 72" of douglas fir. Any guess how long it will need to be dried? I have a large sawmill down the road and I can probably talk them into letting it hang out there for a bit. The guy helping with the new build wants the mantle quickly but I would rather do it right than fast and have to do it again later.

[Don P]

If its just a big hunka wood hanging on a bigger hunka masonry I set it up to be easily replaced either sitting on masonry corbels out of the chimney or steel rods sticking out. For that I just drill holes and slide it onto the rods. You can either make up a blank thick enough to clear the veneer that the mason inserts where the mantle will go and he veneer stones/bricks up to it, pull the blank and insert the mantle or he gets a form that is filled with concrete that brings that rear mount point out to flush with the face of the stone/ brick, whatever. Then if I'm making the mantle out of something green I leave one or two more oversized timbers there to be acclimating until needed.

[GeneWengert-WoodDoc]

Because this wood will be inside, and because of its history, you need to heat it to 133 F throughout to kill any insects and their eggs.  To reach this wood temperature, you will need at least 150 F air temperature.  It might be best to get a commercial operation to work with you.

You should treat any of the pieces that you will use inside or that potentially have insects that will curtail future uses.

Note that the fireplace heat will create a low humidity at the wood's surface and dry the wood quite dry, which means a lot of shrinking and possibly a crack.  One thing that would help is to put a crack full length with a Skil-saw in a place where it will not be seen.  Then most of the movement will change this hidden crack size.  Another help is to hollow out the piece as much as possible.

[jkiesel]

I cut one of the test logs last night and I think I may be barking up the wrong tree (pardon the pun). The wood has some rotten areas and a crack that goes nearly the full length and almost to the center of the log. I am hopeful the nicer logs I set aside will be in better shape since I only see some light checking and I knew this one had some issues.

@GeneWengert-WoodDoc, I will give your idea a try. I have a local sawmill I can have heat the log for me and hopefully by doing that it will expose any flaws right away.

[samandothers]

I have similar plans but are a ways behind you.  If I took my logs to be kilned now I would have to store in my basement or keep in barn and apply boracare which would allow moister back in.

[GeneWengert-WoodDoc]

I may not have been totally clear.

One thing that would help is BEFORE DRYING BEGINS put a deep slot, or man made crack, full length using a Skil-saw. Put this crack in a place where the crack will not be seen when the mantle is in place.  What happens is that most of the movement will change this hidden crack size rather than develop a crack on the good faces.  

Another help is to hollow out the piece as much as possible.