Black Locust fence posts

I'm not only set on using black locust, but I've already cut a couple and hauled them from the woods to my yard (most recently with my neighbor's help pulling with his horse!).

When asking around here, a guy selling black locust posts said they didn't need to be de-barked, that the heartwood would be fine. On the other hand, I've read on this forum and others that black locusts will rot like anything else if not debarked.

Does anyone have a definitive answer to this?

It's strange, from region to region, these subtle differences in practice. Even the different ssp of this family of trees can be amazingly different.

So...

If you want the longest life out of them:

Cut the stock log to the require length.

Debark the log completely.

Charr the base of the post that will be below grade plus 200 mm minimum or you can charr the entire post.

Take rock salt in an oil bath or just the drying oil(s) I have seen and done both.

Place a stone at the bottom of the hole the post will sit on, and only back fill with stones, if possible, that are flattish and elongated. Stack them in "on end" and pack with pounder or another post good and tight.

I have seen post like this that are well over 100 years old.

If you want the post to grow...some will...do not debark or damage the xylem layer...cut the wood in the spring green, treat with hormone if you want (experiment) and water them in...I have seen folks do this with some modicum of success...

Good luck,

j

Black locust makes great fence posts. I wouldn't bother debarking, (but the bark will rot eventually) as the man rightly told you, just make sure your post is at least 5" heartwood. Red cedar is same way preferably 5" red heartwood, debarking unnecessary.

Large diameter posts are fun to split into posts, don't debark, unless you just don't have anything better to do.

james beam

Thank you both for your replies. I do want a long life out of them, but it doesn't have to be the longest possible. It will be a high tensile electric wire fence, and the manufacturer of the wire rates it to have a 25 year life, and since I think that would include coastal environments, maybe longer where I'm at.

Jay-- what do you mean by "Take rock salt in an oil bath or just the drying oil(s) I have seen and done both." Do you mean to soak the posts in tung or linseed oil with salt?

I tried this evening debarking using a billhook (can't remember where I put my drawknife), and it goes fine, so I guess I will at least debark the part that goes into the ground, if nothing else just so that when the bark rots away the post doesn't become loose.

Right now I'm fencing a pretty small area where the goats I have and cattle we will purchase in the next month or two will go for over-winter, so time is a constraint. The other constraint is when I get the fence posts-- the neighbor promised me to go with his tractor where he knows there are a lot of black locusts, but the tractor is broken and he's waiting for a part, so we can get some with his horse closer-by, but there aren't too many there.

Hi,

As others have shared, you really don't have to debark...it just extends life of the post with each step as I shared them, and some post will start to grow if bark is left on them...

Some seem to have really green thumbs, like some of the Elders I have been privileged to work with...if they looked hard at something it seemed to sprout roots and leaves...

With the correct tools, debarking a post is less than 20 minutes, and if you do a lot of them, during the correct time of the years haves, even faster.

As for finishes...there are many!

"Salt oil" is just that warmed oil with salt melted into it. I would suggest experimenting. I use a mix of pine rosin, beeswax, tung oil and flax oil with a citrus oil thinner. Again...there are thousands of recipes....

Remember, again, each step adds life. If you go all out with debark to charr to oiling...100 years is nothing...I seen it even on pine posts...

Good Luck,

j

Jay C. White Cloud wrote:Hi,

As others have shared, you really don't have to debark...it just extends life of the post with each step as I shared them, and some post will start to grow if bark is left on them...

Some seem to have really green thumbs, like some of the Elders I have been privileged to work with...if they looked hard at something it seemed to sprout roots and leaves...

With the correct tools, debarking a post is less than 20 minutes, and if you do a lot of them, during the correct time of the years haves, even faster.

As for finishes...there are many!

"Salt oil" is just that warmed oil with salt melted into it. I would suggest experimenting. I use a mix of pine rosin, beeswax, tung oil and flax oil with a citrus oil thinner. Again...there are thousands of recipes....

Remember, again, each step adds life. If you go all out with debark to charr to oiling...100 years is nothing...I seen it even on pine posts...

Good Luck,

j

You really have me thinking I should just plant my locust where I want the posts to be and nail the fencing to live posts. hmmmmm Would be ever so much easier on me! Rather prettier too.

Jay C. White Cloud wrote:
Remember, again, each step adds life. If you go all out with debark to charr to oiling...100 years is nothing...I seen it even on pine posts...

Going all out, I will save for the swingset I want to make my kids for next year, and the gazebo/picnic/sitting area for my wife.

Am I on the right path with using a drawknife and/or billhook for debarking?

Danielle Venegas wrote:You really have me thinking I should just plant my locust where I want the posts to be and nail the fencing to live posts. hmmmmm Would be ever so much easier on me! Rather prettier too.

The only problem with living trees is that they will swallow insulators as they grow (if its electrical fence). Though, I have been putting around temporary fences with electric twine and "screw-in ring insulators" and just not screwing in so deep on smaller trees that I expect will grow a lot to insure that the insulators will stay outside the tree for 5 or 10 years. For internal division fences though I have thought to try willow posts, as supposedly they sprout and grow quite easily.

Am I on the right path with using a drawknife and/or billhook for debarking?

Yep...

Or a bark spud, or number of other debarking tools. With the drawknife, try keeping the "bevel" down not up...it will typically work better for you and not dig in as much...

As for insulators and trees encapsulating them. Try using screws with a separator of wooden doweling, or drill in and glue in place wooden dowels to attach the insulators to. This way you can back them out as needed. Electric fences need annual inspections and servicing anyway, so if insulators are getting "sucked up" by a tree the maintenance schedule needs to be moved up... Riding the fence was a never ending process for Ranchers and Farmers...

Regards,

j

My favorite debarking tool is a shovel with a long, narrow blade. You get the kind of leverage that a barking spud offers, but the curve of the blade helps it get right in there under the bark. On logs it is so much faster than a drawknife that there is just no comparison.

As others mentioned you dont need to debarked . I have a couple hundred acres of pasture and have black locust, red cedar, Osage orange and mulberry post in for years. White oak igo ahead and age, debarked, and burn the ends like was mentioned in a previous post.

The drawknife worked great. Some of the posts I had cut in August, some in November, I didn't find any real difference in debarking. I didn't time myself, but for the posts in the photo (6x 8' and then two that weren't used), I got them debarked in an afternoon with a lot of interruptions. I did as Jay said, in fact with the drawknife practically flat against the post once it was bit in to the bark, and the bark just came of in strips. The posts were simply leaned against an 'X' made from two posts wired together with their legs in the ground, and mostly I sat on the post and flipped it around when half-way done.

Now I just need a bit drier weather and someone willing to take their tractor to the woods to get more Black Locust.

Jay C. White Cloud wrote:

...

Charr the base of the post that will be below grade plus 200 mm minimum or you can charr the entire post.

...

j

How do you char the posts, Jay? I'm planning to build some post and rail fences to keep stock out of where we have young trees. One source for the posts is Class 3 inground durability eucalypts split from windthrows etc and maybe some local plantation thinnings of Class 2 eucs like spotted gum, coastal mahogany and yellow stringybark. The thinnings would have some heartwood but if I could beef up the inground durability that would be very handy. I need about 5 years out of the fences so treated pine and wire is more fence than I need and expensive. And I'd prefer to use all non-treated local timber

Thanks

David

In Italy we can't use living trees as fence posts, regulations prohibit it. I would like to use living fences but it will take to long and I have a wild pig and deer big problem, so I'll have to fence my land.
One question do you make the posts once they are cut, and after debarking, season for two years?
here some friends have told me chestnut poles must be kept two years to season, I think it's the right term, and even black locust poles.
what do you do? can I just cut and use them?

I cut my posts (other coppice species) and leave them laying for the sheep to debark them.

Tim Wells wrote:I cut my posts (other coppice species) and leave them laying for the sheep to debark them.

Thanks Tim, and after debarking you use them? without letting them season some time? thats nice here there'es this thing about using freshly cut wood, they say it rots first if you don't let it season some time

i use them fresh, like you i need the fence up quick

Lorenzo Costa wrote:here there'es this thing about using freshly cut wood, they say it rots first if you don't let it season some time

Lorenzo,

I don't have an answer for you, but with many traditions there is some good reason, but also countless traditions may not have a reason and may not be true.

Here I'm told that all I need to do for a long lasting fence post is coat it up and down with used motor oil, which I'm not interested in doing even if it works.

As far as using living trees-- are you sure there is really a regulation against it? And would it apply to say some insulators for electric wire fence? And even if it did, would anyone be reporting you? Here (rural Slovakia) I see lots of incorrect knowledge of laws and regulations, and many things which are against the law are anyway done (like distilling liquor in ones backyard!).

-Andrew

Anyone, particularly Jay C. Whitecloud, able to say whether with blacklocust it matters how much heartwood the post has? I went cutting posts with my father-in-law last week from the edge of a semi-abandoned* orchard. Some mostly younger trees were growing on the flat land behind the orchard fence, and then it drops off into a small ravine and down there were the older trees. My father-in-law preferred we cut the trees that didn't require as much effort to get to the trailer!

Each attached photo shows a pair of posts of the same diameter but with different thicknesses of heartwood. Is it only the heartwood in black locust that is rot resistant?

I am filling the bottom and sides of the post hole with crushed gravel (1-4" size), so will rot really be much of a problem for posts that won't be in full contact with soil, but rather mostly rock?

as an aside, I need to fix old wooden ladders where a lot of rungs have cracked. Would black locust be a good choice to turn new rungs from?

* 40 year old apple orchards, that belong to many of the families in the village, but the state still rents and the renter just clears the brush every few years so that the satellite photos the subsidy agency of the government uses will appear still to be active orchard and he'll still collect the 700€/hectare subsidy on it. :-/

Hi Andrew, on the fact we can't use living trees for fence posts, yes it's regulated that way and even the electric fences can't be put on living trees the say the electricity that passes in the fence harms the trees.
Maybe one can do everything and just get away with it even if there are regulations I dont' know I like to discuss with my neighbours explaining what I'm doing, but usually I try to respect these sort of laws.

Seems like I missed some direct questions...sorry about that...

@ David Wood:

Hi David,

How do you char the posts, Jay?

The last time I helped someone with this and/or did it for a challenge course I designed and built, we covered the wood in a "heritage finish" and then used both a campfire and/or a small blow torch to facilitate a rapid charr. I also dipped the posts in a barrel of dissolved rock salt and borax (20 mule team soap) 50:50 solution that was warmed over a campfire (boiled at times). Some sat over night to a week for extra material we had. This was how one of my teachers kept the thinner 'picket post' and bolt section with excessive sap wood in the barn. I am not sure it was a drastic improvement over just plan old locust, cedar, osage and catalpa posts....

I do hope you come back to this conversation over time and report on your findings....please. I would not treat some posts, and bury them directly in the ground as a control, and compare the results to the ones you treat and backfill with stone and gravel as I have described above in this post thread.

Regards,

j

>>>

@ Andrew Ray:

Hello Andrew,

Anyone, particularly Jay C. Whitecloud, able to say whether with black locust it matters how much heartwood the post has?

As you have seen, even in the same tree, the "sap wood" can vary in thickness and character. This behaves in different ways in different species, like in Maples and Sycamores, et al, the heart wood rots rapidly, leaving the sap wood to remain and the tree will continue to live for centuries as a hollow shell, as this seems to be part of the "compartmentalization behavior" for these genera. Even among many Foresters, Arborist, Dendrologist and other academics we don't have complete agreement. I tend to be more "empirical" in my thinking and look to historic record. For locust, osage, catalpa, cedar, it does not seem to make any or very little difference. I will note, however, that I have found strange anomalies in a line of fence post over 100 years old on more than one occasion over the decades, where all appear to be the same species, treated and buried the same and one out of the group will be pithing and hollow?? Not sure why other than I have used locust and cedar that have started to hollow out naturally myself, so perhaps that was what that farmer did themselves...

Is it only the heartwood in black locust that is rot resistant?

No, I don't believe that is the case, and we are even learning more about some other species as well. This could be more "old stories" than fact. Sapwood does have sugars and starches that promote fungal growth, yet some species may also store toxins here as well...perhaps even in higher concentrations? There is still much to learn...

I am filling the bottom and sides of the post hole with crushed gravel (1-4" size), so will rot really be much of a problem for posts that won't be in full contact with soil, but rather mostly rock?

Don't forget the big pointy stones up on end at the bottom, as this keeps the base out of the water that can stand down there before it drains. I have buried white pine and popular post over the years in the ground with stone packing and then without a stone base and packing. With the stone and good drainage stone packed around them, even these rot prone species can last more than ten years or even longer if oiled with traditional oils and salt/nitrate baths, plus charr.

I need to fix old wooden ladders where a lot of rungs have cracked. Would black locust be a good choice to turn new rungs from?

I just returned from a restoration project in Katy Texas on an 1836 barn. Four of the interior posts had ladder holes drilled into it and rungs attached so the farmer could climb to the hay mow. One post is Beech, the other White Oak, the next was Locust and the last Tulip Popular (a type of Magnolia) all the rungs had been made of white oak and locust as I had to make and replace several of the same materials.

I am more prone to say "rive and draw" your rungs...and only turn them after roughing in this way first...Locust is an excellent choice and I have built several apple harvest ladders from locust.

Post in swampy land will, if of a nonresistant species, rot just above the ground. That which is in the hole stays solid, as wood under water doesn't typically rot.

Regards,

j

Just to throw a bit more information into the mix, I had a chat yesterday with an experienced sawmiller from a farming district. He said that many of the fences in his area before treated pine were made from stringybark. (Probably Eucalyptus obliqua.) This is a Class 3 inground durability species so might not be expected to last a long time. Farmers in my area have said that up to 10+ years might be achievable. The sapwood does go first with this species.

The sawmiller said that stringybark posts at the top of the slope and posts at the bottom of the slope would last much longer than posts at mid-slope. He explained this by saying that the posts at the top of the slope would tend to stay dry and the posts at the bottom would tend to say wet. The posts at mid-slope would have more of a soil moisture variation which he thought assisted rot. I should say that this was an opinion given during a quick telephone conversation on another topic so it is what it is.

We had a long boundary fence on our property that had been put in by our neighbour when he was a young fella of 50 or so back in the 1980's. Australian's farmers are aging. This fence was made of what was probably stringybark or similar. The posts had rotted in places but were still functional in others.

As Jay says, this is an area where direct empirical experience is very useful. Look forwards to hearing how others go with their fencing using other than treated pine.

A farmer acquaintance of mine said that a black locust fence post will outlast two holes.