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General Forestry => Sawmills and Milling => Topic started by: Kwill on February 06, 2020, 02:03:09 PM

Title: Log consider froze at what temp
Post by: Kwill on February 06, 2020, 02:03:09 PM
Maybe a dumb question but I'm wonder at what temp a log is considered to be froze and harder to saw. Its 26 here right now and I'm thinking about going out and cutting some cedar while the ground is froze cause it's very muddy here. Just wondering if the logs will give me any trouble at these temps.
Title: Re: Log consider froze at what temp
Post by: Jeff on February 06, 2020, 02:07:40 PM
32 degrees. Same as Ice. When its that cold or colder long enough, the log is froze. Frozen logs aint so tough, it's  half frozen logs that are a pain.
Title: Re: Log consider froze at what temp
Post by: doc henderson on February 06, 2020, 03:07:15 PM
I milled a ERC tree in winter to get ready for our Tappers Rendezvous.  it had a hollow area that was filled with water and froze.  it milled ok and looked like a resin filled void as it sawed thorough the ice.  did not notice much till it started to melt in my shop.  I would assume a frozen tree is harder much like a very dry tree.  might consider a lower pitched blade like a 4 instead of 7 or 10  It got up to 26 yesterday when I was sawing that Hackberry, and it sawed ok in the straight grain, but a branch area gave my blade some wavy fits.  it may have done that anyway.  want to make a few pallets and see how my size works out.  42" deep,  9 feet long.  the crossmember are a full 2 x 4 inches space 18 inches.  
I will joint and plane everything the same in the dimension that matters, for each pallet.
Title: Re: Log consider froze at what temp
Post by: RobS on February 06, 2020, 03:44:33 PM
32 degrees. Same as Ice. When its that cold or colder long enough, the log is froze. Frozen logs aint so tough, it's  half frozen logs that are a pain.
I'll second that.  Sawing hickory is the worst.  Sawing half frozen anything is a close second. Total froze or total thawed is gravy.
In a production mill with a 52" circular saw, the half froze logs would pull the saw all over. I've nicked a few dogs in the spring time when logs were still froze in the center.
Title: Re: Log consider froze at what temp
Post by: Old Greenhorn on February 06, 2020, 04:07:32 PM
Well certainly I am the new kid here but I have sawn frozen and it's not bad, not sure but I must have had half froze at some point, but not much of it. But the worst that stood out for me was half rotten with a water soaked and frozen outer rot zone about 1-1/2" thick. too frozen to scrape or peel, full of dirt and junk. Not fun, but the wood was real pretty underneath, so there is that.
Title: Re: Log consider froze at what temp
Post by: Ron Wenrich on February 06, 2020, 04:11:50 PM
The biggest problems with circle mills and half frozen logs is the sawdust likes to cake on the side of the log.  That's either frozen sawdust spilling out of the gullets unto unfrozen log, or vice versa.  That frozen stuff pushes against your saw and rubs it.  That makes the saw warm to hot and the saw doesn't stand straight.

In addition, you have to have really good shanks.  I always changed mine in the fall and then had the saw hammered.  You can also sharpen a shank, but its not ideal.  The frozen dust is finer, partly due to the nature of ice and that most guys slow down their feedrate.  If the shanks aren't really good, you'll get spillage out of the shanks.  Then the problems start.  

You should also have either a standall bit and a summer shank, or a summer bit and a winter shank.  The standall bit or the winter shank slows down the velocity of the dust in the gullet.  I ran a summer bit and a winter shank all year long.  Most guys do that in my area.  If you run a standall and a winter shank, you'll end up with the same setup as a summer shank and summer bit.  The sawdust velocity won't slow down, and the only thing you've succeeded to do was form a smaller gullet area.  You'll fill it up quicker.

I also cut back on the lead on the saw.  That always seemed to help a bit.  I could also steer the saw by taking a swipe off the leading side of the saw bit.  Its akin to taking off some lead.

The biggest problem with frozen logs is all the dirt that's frozen into it.  It'll dull a lot quicker.
Title: Re: Log consider froze at what temp
Post by: Jeff on February 06, 2020, 04:12:51 PM
Half frozen with a circle saw is very apparent. Not so much as they thaw but as they freeze.
Title: Re: Log consider froze at what temp
Post by: moodnacreek on February 06, 2020, 06:52:30 PM
Live trees don't freeze. Fresh cut logs may not freeze until a few weeks have passed. The sapwood contains the moisture that freezes. If the species has little sapwood there will be less trouble. The saw may get pressed to the board side when taking off the jacket boards, messing up your cant size making the board fat. Then no more trouble til the next log. The exception to this is logs like hard maple because there is no heartwood, all sap. It takes a sawyer better than me to handle frozen maple logs.
Title: Re: Log consider froze at what temp
Post by: Kwill on February 06, 2020, 10:26:44 PM
These will be fresh cut cedar trees
Title: Re: Log consider froze at what temp
Post by: moodnacreek on February 07, 2020, 07:51:26 AM
These will be fresh cut cedar trees
The sooner the better.
Title: Re: Log consider froze at what temp
Post by: Ron Wenrich on February 07, 2020, 10:06:34 AM
Live trees don't freeze. Fresh cut logs may not freeze until a few weeks have passed. The sapwood contains the moisture that freezes. If the species has little sapwood there will be less trouble. The saw may get pressed to the board side when taking off the jacket boards, messing up your cant size making the board fat. Then no more trouble til the next log. The exception to this is logs like hard maple because there is no heartwood, all sap. It takes a sawyer better than me to handle frozen maple logs.
Live trees do freeze.  I've heard them pop in the woods and I've seen frost cracks in live trees and logs.  What doesn't freeze is the live cells.  This is because the cells shrink in size and their membranes become pliable.  That allows them to expand without rupturing.  In addition to lower water content, there is a higher sugar content in the sap, and that acts a bit like antifreeze.  
Title: Re: Log consider froze at what temp
Post by: doc henderson on February 07, 2020, 10:23:41 AM
everything can freeze depending on the temp.  sugar is a good antifreeze, just need electrolytes to disrupt forming organized ice crystals. ethylene glycol is a sugar alcohol that lowers freezing temp, and also tastes sweet which is why you cannot leave it out where a dog can drink it.  salt works too but is corrosive.  Polyethylene glycol where the molecules are hooked together (PEG) is non toxic, and used to stabilize wood and as a laxative in humans.  Miralax.
Title: Re: Log consider froze at what temp
Post by: moodnacreek on February 07, 2020, 01:08:01 PM
To me frost cracks are rare in trees with no openings. Also  have never had frost sawing trouble in logs just cut [off the stump]. Logs here started to freeze in the first cold spell but not now. This time of year I saw 6 days a week and it is much easier frost free. What happens in colder country I don't know about. Same for species I don't handle.
Title: Re: Log consider froze at what temp
Post by: Jeff on February 07, 2020, 01:33:54 PM
Not rare at all if you live in the land of ice and snow. Id say more prevalent in smooth bark trees like aspen and alders.
Title: Re: Log consider froze at what temp
Post by: Kwill on February 07, 2020, 09:25:21 PM
 
(https://forestryforum.com/gallery/albums/userpics/42883/20200207_110356.jpg?easyrotate_cache=1581128580)
 
(https://forestryforum.com/gallery/albums/userpics/42883/20200207_110412.jpg?easyrotate_cache=1581128568)
 
(https://forestryforum.com/gallery/albums/userpics/42883/20200207_122020.jpg?easyrotate_cache=1581128559)
 
(https://forestryforum.com/gallery/albums/userpics/42883/20200207_125048.jpg?easyrotate_cache=1581128652)
 
(https://forestryforum.com/gallery/albums/userpics/42883/20200207_175722.jpg?easyrotate_cache=1581128650)
 Cut milled and installed. No problem with frozen. 
Title: Re: Log consider froze at what temp
Post by: WV Sawmiller on February 07, 2020, 10:46:31 PM
   Related question here - aren't some trees naturally drier , i.e lower moisture content, than others so don't they saw easier in normally frozen conditions than others? I thought cedar and I know ash have a naturally lower moisture content than others. Wouldn't they saw more like normal, non-frozen conditions?
Title: Re: Log consider froze at what temp
Post by: doc henderson on February 07, 2020, 11:15:09 PM
@Kwill (https://forestryforum.com/board/index.php?action=profile;u=32883) but won't that make it cold in your shed. :D :D :D I bet less dense wood may be easier to saw than denser wood, frozen or not (off the top of my head).  by definition and somewhat counter intuitive, a less dense tree could have a higher MC since it is based on the weight of the water vs the dry weight of the wood (lower weight in less dense wood).  I also have sawn frozen ERC as mentioned and had no trouble.  I have heard that about ash as well, but do not have first hand scientific knowledge.  @GeneWengert-WoodDoc (https://forestryforum.com/board/index.php?action=profile;u=20498)
Title: Re: Log consider froze at what temp
Post by: barbender on February 07, 2020, 11:39:48 PM
We have 2 ash species locally- green and black (though everyone calls green ash white). Green ash is very low moisture, black ash is much higher- it saws very similar to red oak. I doubt it would change green ash's behavior much being frozen, but it's behavior isn't much to brag about in the first place😁 Live trees definitely freeze up here, at least hardwoods. I'd say hard maple and red oak are most prone to it, though I've seen frost cracks in all of our hardwood species. If you go outside on a nice, still, -30F evening, our hardwoods will sing to you😊
  Kwill, that is some fine cedar you have there👍
Title: Re: Log consider froze at what temp
Post by: Kwill on February 08, 2020, 04:10:07 AM
@Kwill (https://forestryforum.com/board/index.php?action=profile;u=32883) but won't that make it cold in your shed. :D :D :D I bet less dense wood may be easier to saw than denser wood, frozen or not (off the top of my head).  by definition and somewhat counter intuitive, a less dense tree could have a higher MC since it is based on the weight of the water vs the dry weight of the wood (lower weight in less dense wood).  I also have sawn frozen ERC as mentioned and had no trouble.  I have heard that about ash as well, but do not have first hand scientific knowledge.  @GeneWengert-WoodDoc (https://forestryforum.com/board/index.php?action=profile;u=20498)
It's actually will make it warmer. There is going to be 2 doors that swing in put on the end which is the south end so that I can open and close them to get out of the south and south west wind.
Title: Re: Log consider froze at what temp
Post by: richhiway on February 08, 2020, 04:58:19 AM
Ha. I think he missed your joke, Doc.

That is a good looking shed, I hope to start mine soon. Must be nice to have the mill out of the weather.
I know that pine is harder to saw when frozen,or half frozen. After reading the above I bet it has something to do with the sawdust on the bandsaw also. It clumps up and sticks. 
Title: Re: Log consider froze at what temp
Post by: doc henderson on February 08, 2020, 05:30:11 AM
yes, I thought surely all that frozen wood would make it colder in there.  even though there is not yet a roof or walls. :) :) :)
Title: Re: Log consider froze at what temp
Post by: PA_Walnut on February 08, 2020, 07:25:09 AM
A laser thermometer is helpful when you suspect your logs may/could be frozen. I store my logs in the shade and if there's a cold spell, then warms it's difficult to guess if they are frozen or not. A zap with the laser at a few spots (once opening the log) will take the guess work out.

Good luck.
Title: Re: Log consider froze at what temp
Post by: moodnacreek on February 08, 2020, 08:38:01 PM
  Related question here - aren't some trees naturally drier , i.e lower moisture content, than others so don't they saw easier in normally frozen conditions than others? I thought cedar and I know ash have a naturally lower moisture content than others. Wouldn't they saw more like normal, non-frozen conditions?
A bsolutely, the drier the better as far as frost is concerned. The heat at the teeth is just enough to thaw the frozen sap as it is made into sawdust. But instead of shooting out of the kerf it refreezes in the kerf and the side that gets the most pushes the saw blade off line.
Title: Re: Log consider froze at what temp
Post by: moodnacreek on February 08, 2020, 08:43:24 PM
Not rare at all if you live in the land of ice and snow. Id say more prevalent in smooth bark trees like aspen and alders.
Wouldn't know an alder if I tripped over one but aspen, yes, that wood can be more water than wood.
Title: Re: Log consider froze at what temp
Post by: barbender on February 08, 2020, 09:12:34 PM
Here's a nice "sunburst" frost cracked black ash. That type of frost crack is common in black ash and red oak up here.

(https://forestryforum.com/gallery/albums/userpics/11286/20200208_132154.jpg?easyrotate_cache=1581214262)
Title: Re: Log consider froze at what temp
Post by: barbender on February 08, 2020, 09:15:17 PM
Try that again with some zoom🙄

(https://forestryforum.com/gallery/albums/userpics/11286/20200208_201647.jpg?easyrotate_cache=1581214451)
Title: Re: Log consider froze at what temp
Post by: moodnacreek on February 09, 2020, 08:45:21 AM
Try that again with some zoom🙄

(https://forestryforum.com/gallery/albums/userpics/11286/20200208_201647.jpg?easyrotate_cache=1581214451)

Up on our mountains white oak can do this and I never knew what caused it.
Title: Re: Log consider froze at what temp
Post by: jeepcj779 on February 09, 2020, 12:48:25 PM
That appears to be a butt log.
Title: Re: Log consider froze at what temp
Post by: barbender on February 09, 2020, 01:50:25 PM
It is
Title: Re: Log consider froze at what temp
Post by: Resonator on February 09, 2020, 03:48:26 PM
Those wood make nice cookies.  ;)
Title: Re: Log consider froze at what temp
Post by: doc henderson on February 09, 2020, 05:21:17 PM
just have to keep them in the freezer!! :) :)
Title: Re: Log consider froze at what temp
Post by: barbender on February 09, 2020, 10:45:26 PM
They typically fall apart.
Title: Re: Log consider froze at what temp
Post by: Don P on February 09, 2020, 11:21:23 PM
The truck, trailer and Lucas are on the other side of a creek and the frost went out today. Sawing was easy, the question now is, at what temp will the mud freeze back up :D