Introduction And Question On Rot Resistant Wood

[Ron Wenrich]

Just when you think you know something, you read up on some research, and things change.  Apparently, there are different strains of black locust.  They also have differing amounts of rot resistance.

Of all the varieties, there is one called a shipmast locust.  This has durability that is rated in the 50-100 year range.  It also matters how big the tree is, and where the post is taken from that tree.  Posts that are taken from the outer most part of the heartwood in butt logs will have the most rot resistance.  Posts taken farther up the tree will be the least rot resistant. 

There is a little lessening of the rot resistance of trees cut in the spring vs those cut in the winter.  The common locust has less durability, about 10-30 years.  Slower growing trees were more rot resistant.  One indicator is the more yellow the wood, the more resistant.

Here's the read:

http://blacklocustlumber.com/pdfs/Decay_Resistance_Of_Black_Locust.pdf

I didn't see anything that had to do with drying the wood.  That's not to say a relationship doesn't exist.  I do know there is a wide variability of any specie over its range. 

[moonhill]

I am wondering if Magicman's test results were slanted from the logs being cut from different parts of the tree?  I guess it will take another 50 years for the test results to come back.  Look for the sap ring and if there is more sap wood cut it off with the saw, if the log size allows.  The locust post I have seen were in the ground for 25 years and I am sure they would have gone 25 more with no questions, the outer ring of 1/2" sap wood was soft, the core was like it had just been felled.  I notice the color to be green/PTish then dries to a yellow. 

Tim 

[Magicman]

My home town of Lorman, Ms. had a huge billboard proclaiming it to be the "Locust Post Capital of the World".  Through the 1950's after we got the cotton picked, it was "post cutting" time.  Most all of the landowners cut post, because it was the only cash crop during the winter.

The post were put on rail cars and went to ?.  I don't know who the buyers were, but they only took seasoned post.  Some folks cut and stacked them 10 one way and then 10 the other until the stack had 200 post.  They stayed there until the next year and then loaded on the rail cars.  There were 10's of thousands of post stacked between Hwy. 61 and the RR tracks.

I worked for my granddad, and he did it another way.  We never stacked ours, because he didn't want to handle the post but once.  We cut the post from trees that we had felled the previous year.  We were paid 5 cents per post and cut them with a 5' crosscut saw.  Granddad sharpened and set the saw.  You could hear it "sing" going through the locust.   After we had cut all of the trees up into post and hauled them to the rail yard, we then proceeded to cut live trees down for next year.  We felled them across each other which kept them off of the ground.

After the post cutting was over, we hired out to build fences.  Tough work and I was paid 5 cents per post hole.  Other kids at school didn't want to "arm wrestle" with me.

My experience with Locust Post didn't come out of a book.  I learned it the hard way, and listened to what the "old folks" told me.

Yes, the bark and sapwood is the killer...Rotter......Don't put it in the ground.

As a note, the cross arm pins that held the glass insulators on telephone open wire circuits were made out of heart black locust....

[Banjo picker]

How does locust cure out when cut into lumber ?  Imagine it might be tough to work.  Tim

[Magicman]

Tim, I've only cut it 1 1/2" for trailers and 2" for bridge decking.  I've not had any significant cupping or warping.  It's so hard, I don't believe that it could shrink much.

[dmartin]

I finished the shed this weekend and put some impliments in it. I took a few more pictures that I'll post. It sure is nice to call it done.
As for the guardrail posts I think I may use Catalpa, my brother inlaw has a Catalpa that needs to come down and with my winch we can easily make it fall the right way (away from the power line).   

[/img]

[Magicman]

Now, that's what I call OK.....