Drying logs and limbs without cracks?

[Blue42]

...okay, after I posted this thread the site recommended a similar thread....posted by none other than, me, on, the same topic.
https://www.arboristsite.com/threads/prevent-debarked-logs-cracking-in-the-sun.368111/

My memory, it isn't good. I searched for "drying" before posting this and saw nothing. And I looked to delete this thread after seeing the old one, but it doesn't look like I can. So, let it roll I guess.
I do have another example since that thread, of a white oak that wasn't left in the sun at all.


Is there anything to do with logs so that they won't crack? If you leave the bark on, the log rots, in my experience, and the bugs love it. But if you strip the bark, the log--at least beech--will crack all the way to the middle.
The two shots of the logs next to each other are white oak that was cut, debarked right away, painted with end sealer, and stored out of the sun. The tree only fell a couple months ago. The other two pictures, laying on the grass, is a beech log that was debarked right away and stored mostly out of the sun.
And this isn't just end cracks. Some of them go the length of the log.
Chestnut oak seems to do a lot better. A 2.5' tree fell and there were no deep cracks. The bark had been left on it for months.

I had some nice 6" thick beech limbs that have now all cracked. I was going to make table legs and stuff out of them. Not so much now.

 

[Mad Professor]

Anchor Seal the ends as soon as you cut them.

 

[Blue42]

Did that right away. Always do. But the cracks along the length of the log. ? It's like the way a cookie splits, times the entire 9' log.

 

[Coralillo Lo Pro]

I think immediately Anchor Sealing the ends as MP says AND leaving the bark on would go a long way to keeping cracking from happening along the whole length. I try to keep all the bark on the cookies I cut while Anchor Sealing the faces, and if I was to remove the bark I'd Anchor Seal the sides. I have no problem with oak/ash and harder hardwoods rotting while leaving them with bark on for ages. But generally I mill most logs right away. I've never worked with beech so can't speak to it. Any wood you strip bare is going to dry faster on the outside than the inside and be prone to cracking especially with all kinds of tensions going on in a whole log as the outside dries fast while the inside nearly doesn't at all. Disconnecting wood from the pith by milling logs helps eliminate a lot of the ruinous difference in drying rates and weird internal tensions. If you're just trying to square off entire limbs as legs and leave the pith intact in them, you'll probably have more cracking issues than with larger log slabbing. Bugs I tend to live with if they're just borers and trust they'll keep their attentions to the bark/sapwood.

 

[Mad Professor]

Are you putting them in the sunlight?

Dry them in the shade.

 

[singinwoodwackr]

Drop them in a nearby pond

 

[Blue42]

The problem leaving bark on is that after it dries I've just about had to chisel it off. Hours, and hours of work. If it's still wet it comes off in about a tenth of the time. And the big black beetle grubs like rooting around under the bark. Both the sweet gum and the beech that I didn't get the bark off fast enough got some rot. Especially the sweet gum. The oak was okay, but the sapwood was punky in places. I took that as a lesson---get the bark off fast, or you'll regret it.
I don't know how other people are able to leave bark on their logs without an issue. Maybe if you can get them out of the woods and off the ground right away. And don't live in the mid Atlantic.

A couple pieces of beech I milled, I anchor sealed some of the face area that was end grain. Then I sprayed it with boracare. Well, the powderpost beetles were still chewing holes in it even after I sprayed the slabs a second time; I assume because it didn't penetrate the Anchorseal. I could see the spray beaded up over it so I knew it wasn't.

Darned if you do. Darned it you don't.

 

[Seachaser]

Drop them in a nearby pond

 

[GeneralKayoss]

The problem leaving bark on is that after it dries I've just about had to chisel it off. Hours, and hours of work. If it's still wet it comes off in about a tenth of the time. And the big black beetle grubs like rooting around under the bark. Both the sweet gum and the beech that I didn't get the bark off fast enough got some rot. Especially the sweet gum. The oak was okay, but the sapwood was punky in places. I took that as a lesson---get the bark off fast, or you'll regret it.
I don't know how other people are able to leave bark on their logs without an issue. Maybe if you can get them out of the woods and off the ground right away. And don't live in the mid Atlantic.

A couple pieces of beech I milled, I anchor sealed some of the face area that was end grain. Then I sprayed it with boracare. Well, the powderpost beetles were still chewing holes in it even after I sprayed the slabs a second time; I assume because it didn't penetrate the Anchorseal. I could see the spray beaded up over it so I knew it wasn't.

Darned if you do. Darned it you don't.

If the tree is cut in winter, the bark will do this. If it's cut in summer it will come off easily in time.

 

[Blue42]

If the tree is cut in winter, the bark will do this. If it's cut in summer it will come off easily in time.

Hmm. I have only cut one tree, and the others I've milled all fell on their own. A big Chestnut oak fell in the summer. And that bark didn't come off without a serious fight, about 5-6 months later. If I was able to leave it on longer into the next stage where it's really dried out, then I could see it flaking right off. But by then the water has gotten under the bark and sat there, like somebody wearing a wet coat for days, rotting the wood underneath.
I just don't know how to leave the bark on--so the log do ant split--but not have the logs chewed to pieces by beetles, rot underneath the wet bark coat, and then have to chisel the bark off in the end.

 

[Coralillo Lo Pro]

I think the problem may just be in storing whole logs and working them six months to a year later. They're harder to mill left to dry as whole logs, and the center wood never really dries much while the outside wood dries fairly quickly if debarked, leading to cracking. I think you're always better off milling logs as green as possible. With proper stacking and strapping and sealing the ends, you'll get much more even drying and better results. Most of my bark-on dried slabs separate fairly easily from the sapwood using a hammer and chisel if I'm doing a live edge piece, and otherwise I just trim it off with a saw. It's a popular misconception there's any advantage to letting a whole log dry awhile before milling.

 

[GeneralKayoss]

Hmm. I have only cut one tree, and the others I've milled all fell on their own. A big Chestnut oak fell in the summer. And that bark didn't come off without a serious fight, about 5-6 months later. If I was able to leave it on longer into the next stage where it's really dried out, then I could see it flaking right off. But by then the water has gotten under the bark and sat there, like somebody wearing a wet coat for days, rotting the wood underneath.
I just don't know how to leave the bark on--so the log do ant split--but not have the logs chewed to pieces by beetles, rot underneath the wet bark coat, and then have to chisel the bark off in the end.

I was told this by a fella that has run a big tree service for about 35 years. Didn't really have time to get all the details from him. Some trees have bark that just doesn't like to release, and some releases easier. Now, as to any benefits to letting a log dry, IDK. Wood is probably more stabile once you mill it but it's going to be harder to mill. It's going to be lighter to move around too but you also run the risk of deep log checks. I'd say, if you are going to store logs, store them off the ground and under a shelter. Older salvaged logs can be fun to work with, I just finished this bench and it came from logs that look just like these grey ones, but bigger, in the photo. Had checks 3-4 inches deep all along the outside.

 

[Woody912]

"Understanding Wood

...okay, after I posted this thread the site recommended a similar thread....posted by none other than, me, on, the same topic.
https://www.arboristsite.com/threads/prevent-debarked-logs-cracking-in-the-sun.368111/

My memory, it isn't good. I searched for "drying" before posting this and saw nothing. And I looked to delete this thread after seeing the old one, but it doesn't look like I can. So, let it roll I guess.
I do have another example since that thread, of a white oak that wasn't left in the sun at all.


Is there anything to do with logs so that they won't crack? If you leave the bark on, the log rots, in my experience, and the bugs love it. But if you strip the bark, the log--at least beech--will crack all the way to the middle.
The two shots of the logs next to each other are white oak that was cut, debarked right away, painted with end sealer, and stored out of the sun. The tree only fell a couple months ago. The other two pictures, laying on the grass, is a beech log that was debarked right away and stored mostly out of the sun.
And this isn't just end cracks. Some of them go the length of the log.
Chestnut oak seems to do a lot better. A 2.5' tree fell and there were no deep cracks. The bark had been left on it for months.

I had some nice 6" thick beech limbs that have now all cracked. I was going to make table legs and stuff out of them. Not so much now.

"Understanding Wood" by Bruce Hoadley talks about submerging pieces in 1000 molecular weight PEG for quite some time but he is working with carving pieces. Don't know if this is practical for your application but probably the only way to keep wood from cracking.

 

[Chainsaw Pete]

"Understanding Wood

"Understanding Wood" by Bruce Hoadley talks about submerging pieces in 1000 molecular weight PEG for quite some time but he is working with carving pieces. Don't know if this is practical for your application but probably the only way to keep wood from cracking.

PEG changes the characteristics of the wood somewhat, and will limit your finishing choices (some finishes will simply not be accepted by PEG soaked wood). PEG in quantities needed to submerge a whole log - not to mention the vat - will cost a few bucks.

 

[Blue42]

Thanks for the ideas. It's a question I'm still learning about. I still don't know why some logs in some places can be left whole, and don't seem to rot even with the bark on, or don't seem to crack even with the bark stripped, whereas others rot to the core if bark is left on, and others crack all the way to the core if the bark is stripped.
I have a chestnut oak that fell out there that's been down for six years. On the pieces that I didn't process, the bark was left on, and the sapwood is long gone into dust and beetle food, whereas the heartwood is untouched in most places. So it didn't rot. And, less surprisingly, it hasn't cracked.

 

[Coralillo Lo Pro]

Interesting article I found online that explained some of this, when someone was asked why many "sinker logs" are still fine, but others exposed to a bit of weather end up rotting. I never really had understood myself what makes some logs rot and others not until reading this.

"Decay fungi are primitive plants, and like most other organisms, they require four basic conditions to survive. In some respects, they need the same things that people need to live:

Oxygen. In most cases, the air needs to contain at least 20 percent oxygen for decay fungi to operate.

Water, but not too much. Water is essential for all living things, and decay fungi are no exception. Wood is porous and can hold water, much like a sponge. If there is only a little water present in the wood, the fungi cannot survive. If there is too much, it can deprive the fungi of the oxygen it needs — as in the case of the logs in your question, which were completely submerged under water that had a low oxygen content. A moisture content of 20 percent to 30 percent provides sufficient water for fungi while allowing oxygen to be present within the wood cells.

Moderate temperatures. The ideal temperature for decay fungi is between 70°F and 90°F. Most decay fungi die when exposed to temperatures above 130°F and become dormant at temperatures below 40°F.

Food. In this case, the food for the fungi is the wood itself. In addition to being a food source, wood shelters the fungi, insulating it from temperature extremes and providing a reserve of oxygen and water.

All of the above conditions must be met in order for decay fungi to thrive — if even one is removed from the equation, fungi cannot attack the wood.

Building codes allow the use of naturally decay-resistant woods such as redwood and western red cedar. However, this isn’t as simple as it sounds. Because older trees contain a higher concentration of extractives that protect the heartwood, there is believed to be a direct correlation between the age of the tree and the natural decay resistance of its heartwood. We don’t harvest centuries-old cedars and redwoods anymore, but we do harvest much smaller second- (and third- and fourth-) growth trees. These younger trees contain more sapwood and less heartwood. The outer band of sapwood, however, has little to no decay resistance."

 

[Chainsaw Pete]

I still don't know why some logs in some places can be left whole, and don't seem to rot even with the bark on, or don't seem to crack even with the bark stripped, whereas others rot to the core if bark is left on, and others crack all the way to the core if the bark is stripped.
I have a chestnut oak that fell out there that's been down for six years. On the pieces that I didn't process, the bark was left on, and the sapwood is long gone into dust and beetle food, whereas the heartwood is untouched in most places. So it didn't rot. And, less surprisingly, it hasn't cracked.

You are not asking the right questions. By this I mean are you comparing different species or different logs of say white oak? As logs dry, the shrinkage of the fibers sets up stresses inside the wood that result in cracking and checking. I suspect the only way to dry an entire log would be under very carefully controlled temp/humidity conditions in an environment that is beyond the means of individuals.

Once, on a trip home from New York, I visited several lumber yards that sold exotic lumber in large slabs. All of them had carefully stickered slabbed whole trees and they sold to high end furniture makers. One guy told me they rarely filled orders for less than $10,000. The slabs I saw ranged from 1"+ to 3 and 4" thick.

If you want the definitive answer to your question, I'd think you need to read the primary sources - Bruce Hoadley's book is a good place to start. I know the US Forest Service has some publications on drying wood, but most of what I've seen is for what I'd call 'commercial lumber'.

If the rule of thumb for air drying boards is a year per inch of thickness, then you are going to spend a lot of time learning what is already known. Where do artists who carve large pieces get their 'perfect' chunks? I suspect they work around cracks and splits. I'v also seen large turning blocks that are entirely coated in wax...again to slow the drying and allow stresses to relieve themselves without checking. This doesn't always work but it suggests you might have to coat the entire log and allow it to dry slowly.

 

[Tim Pettigrew]

Apologies for coming in late on this interesting discussion. I have always been taught and also observed that the splitting stresses are concentrated initially around the pith. So a freshly felled log should be slabbed as soon as possible and the slab containing the pith discarded.. But it also depends on the species. Oak and beech are very unforgiving in that respect whilst species such as Horse Chestnut (Aesculus hippocastanum) show very little degredation even when the logs are left in the round.

 

[Coralillo Lo Pro]

Two different discussions going on here - the decay fungi causing rot, and the internal tensions causing splitting which the last two posters have offered good insight on. Go to wood-database.com and look up the tangential/radial shrinkage and overall volumetric shrinkage, as well as wood density. The denser the wood, the greater the internal stresses are likely to be, and when there's volumetric shrinkage over 15 percent (common to most oaks, and beech) and a tangential/radial ratio of greater than two, it's almost certain some of the wood is going to crack when drying, especially around the pith and burls. White oak is one of the few oaks with less than a 2.0 T/R ratio, so it fares better than most other oaks. No good can come out of leaving a log to dry whole before milling, far as I can see, unless you're looking to create some interesting checking patterns.