Black Locust fence posts

Larry Caldwell · Oct 16, 2011

Realize that it is the black locust heart wood that is rot resistant. The sap wood, not so much. When you look at the end of the round, visualize the post after the sap wood has rotted away. You need about 3 or 4 inches of heart wood to make a solid post.

feedjake · Nov 8, 2011

Soo I keep waiting for the temps to drop so I can harvest the trees when the sap is "down". But it's so warm here in the State of Ohio. The RFD-TV 90 day forecast showed "below normal" temperatures. However it seems way warmer than normal. Today it was 69 degrees. The lows get cool, around upper 30's to upper 40's.
I should wait for when the temps stay below 40 for the highs for at least a couple weeks I imagine. Any thoughts?

Garybake · Nov 8, 2011

I agree feedjake, wait for ground temps to drop below 40F then you know sap has stopped running. Next week's nightimes in 30'sF will change that rapidly with the shorter sunlight daytimes. Up here in MI we still have a lot of leaves still hanging on, ecspecially the Silver Maples. It is just a shame daylight savings has shortened evening light times to 6:00pm.
Gary

turnkey4099 · Nov 9, 2011

Ken45101 said:
Black locust, or HONEY locust? There is quite a difference in the two.

The USFS lists the following species as being the most rot resistent, even in the top category:

Highly resistant:
Black locust
red mulberry
Osage Orange
Pacific Yew.

Honey locust is in the moderate resistance category.

See:
www.fpl.fs.fed.us/documnts/fplrn/fplrn153.pdf

BTW, it does mention that rot resistance ONLY applies to the heartwood of all species, not to the sapwood.

Ken

Black Locust is jusst about rot "impossible". I removed a 5"x5" post in my basement. Bottom was planted in wet dirt holding up a main beam (I was rehabbing a house). I knew that it had to have been in there somewhere around 30 years at least. Yep, rotted...about 1/8" deep around the outside. I had to chainsaw it off.

As for the common "treated" 4"x4" posts and the round treated posts. Lucky to get 8years out of one. Those are made from peeler cores, about he worst wood in a tree.

Harry K

Ken45101 · Nov 9, 2011

turnkey4099 said:
As for the common "treated" 4"x4" posts and the round treated posts. Lucky to get 8years out of one. Those are made from peeler cores, about he worst wood in a tree.

Harry K

You have to be watchful with "treated" wood. Nowadays, some is "treated" but not rated for ground contact. Others are rated for ground contact. Good fenceposts should be rated for ground contact, of course. I pulled some posts that had been in the ground for 8 years and they were in perfect condition. I just relocated them on some new fence. Some were set in concrete and went into new holes with the old concrete still around them and added new concrete around them.

OTOH, "landscape timbers" are a joke. We removed a garden that had landscape timber edging and they were totally eaten out in 4-5 years. How do you landscape without touching the land? I also noticed where I used one for a cross brace (no ground contact) and it is rotted out in the center.

Ken

feedjake · Nov 9, 2011

turnkey4099 said:
Black Locust is jusst about rot "impossible". I removed a 5"x5" post in my basement. Bottom was planted in wet dirt holding up a main beam (I was rehabbing a house). I knew that it had to have been in there somewhere around 30 years at least. Yep, rotted...about 1/8" deep around the outside. I had to chainsaw it off.

As for the common "treated" 4"x4" posts and the round treated posts. Lucky to get 8years out of one. Those are made from peeler cores, about he worst wood in a tree.

Harry K

Your 5x5 post you removed, did it still have the bark on it our was it a hewn beam/post?

turnkey4099 · Nov 10, 2011

magicheater said:
I'd cut them to length, stack em and let them sit a few years before "planting" them. Stick them in the ground too soon and they may grow on ya! I cut some black locust logs that had been sitting in a pile with other species for 7 years. The poplar was powder, the maple was punky, the oak was salvagable but the Locust was as sound as ever and actually had a green color. Burns really hot too.

I am burning Black Locust this season that I cut and stacked outside in either 93 or 96. Not a sign of detioration and that includes the layer that was in ground contact all those years.

Harry K

turnkey4099 · Nov 10, 2011

feedjake said:
Your 5x5 post you removed, did it still have the bark on it our was it a hewn beam/post?

Rough sawn, not planed.

Harry K

Ken45101 · Nov 10, 2011

One of the problems with locust posts is that they are so hard to get a nail into them

I just added a couple of boards for a fence going off to the side of an exiting fence. I wimped out and used a drill and lag screws :laughing:

Ken

turnkey4099 · Nov 11, 2011

Ken45101 said:
One of the problems with locust posts is that they are so hard to get a nail into them

I just added a couple of boards for a fence going off to the side of an exiting fence. I wimped out and used a drill and lag screws :laughing:

Ken

Or to get a nail _out_ of. I cut down an old locust with a derelict tree house. Teh only way I could get rid of the nails was to "whittle" them out with the splitter. Thin pieces with the nails in them went in the trash. I had one chunk with a big screw eye in it. Tried unscrewing it and onle twisted it.

Harry K