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Blanks From Logs

R

Randy Heinemann

Joined
Jul 19, 2017
Messages
464
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440
Location
Roscoe, Illinois
I recently acquired a number of cherry and apple logs and have already sealed the ends. I would like to cut them up for blanks and have a couple of questions. I am relatively new to turning and have not, to this point cut blanks from logs.

Since this wood is meant to be turned into bowls, is the correct way to create blanks sawing the logs in half lengthwise? Since they are small enough I can do this on my bandsaw with a jig I have access to that will hold the log stable.

If I wanted to use these for taller hollow vessels can I merely take a slice off the end of the log that is just more than the required height of the vessel?
 
You normally need to remove the pith from the blank which requires cutting the log down the center. You also want to complete this process before the log loses too much water and starts to check and crack and create splits from the log shrinking from moisture loss and drying. Sealing the ends of the logs will gain a few days of time, but the best practice is to cut and process the logs within a few days after felling the tree. There are a number of videos on YouTube that demonstrate the process of cutting the logs and sizing and processing into bowl blanks and spindle blanks.
 
Mike Johnson said:
You normally need to remove the pith from the blank which requires cutting the log down the center. You also want to complete this process before the log loses too much water and starts to check and crack and create splits from the log shrinking from moisture loss and drying. Sealing the ends of the logs will gain a few days of time, but the best practice is to cut and process the logs within a few days after felling the tree.
Click to expand...

To add on: the apple is extremely susceptible to drying stresses; the cherry a bit less so. ASAP, the apple needs to be sliced lengthwise removing the pith and maybe the first 5 years of rings (I don’t know diameter of the logs). Then it needs to be end-sealed very well. It will warp and twist and contort and try to pull itself apart. Good luck keeping it in bowl blank form. Consider slicing it into 1.5” planks on your bandsaw instead. Regardless, try to salvage the center slice(s) as the quarter-sawn configuration is wonderful for small projects.
 
Here's one short "How To" from Wood Magazine: Preparing turning blanks

I ran across some really bad videos on preparing turning blanks with a chainsaw so I suggest that if you use a chainsaw that you get instruction from somebody who is very proficient in their use. They are very dangerous if not treated with the utmost respect.

Here is a pretty good video on cutting turning blanks on the bandsaw:

View: https://www.youtube.com/watch?v=NlhhqM3hwb8


The thing that I would do differently is to go a bit further and make the pieces shorter and cut off the corners. Then instead of drying the whole half log I would rough the bowl while the wood is green and wet. Turning wet wood is almost more fun than the law allows, especially if the wood is cut in the early spring when the wood is sopping wet. It's almost like a water ride at a theme park. :D

Anyway, when you turn wet wood, it is turned extra thick and coated with Anchorseal (a water and wax emulsion also sold as Green Wood Sealer at Woodcraft, Rocklers, Craft Supplies, and Packard Woodworks). Then it is allowed to slow dry for about four months (sometimes two or three, but four is a safe number). During the drying process it will warp considerably which is the reason for turning it extra thick. The dry bowl is mounted back on the lathe and centered as best as you can, it is bit of a judgement call. Then you do the final turning to get the bowl round again then sand and finish. The rule of thumb for how thick to rough turn a bowl is to make the wall thickness at least one tenth the diameter of the bowl. In other words if the bowl is ten inches in diameter then make the wall thickness one inch. For bowls smaller than that I wouldn't go much less than 3/4 inch wall thickness, at least not until you have some experience and develop a feel for how wood moves during the drying process.

Don't try to speed up the drying. The intent of air drying wood is to do it very slowly. If it dries too fast it is very likely to develop cracks.
 
If your logs are 6 feet or more in length you can leave them whole and discard 4” or so from the end when you begin cutting blanks from it,

For how I work with with green wood. See this thread
http://aaw.hockenbery.net/WORKING WITH green wood-HOcompressed.pdf

It has links to a demo I do. Slides, roughing a bowl for drying video and returning a dried bowl video.
There are lots of tips of working with the wood movement instead of fighting it. Here is the slide that shows why I cut log sections in half - the tangential shrinkage can take place without the log cracking.


10918C7C-9DAD-4527-A25D-834B01579B0A.jpeg
 
"Ripping" with a chain saw goes better with a very sharp chain, and preferrably a professional grade chain instead of the anti-kick back "home owner chains" With all chains saws there are dangers, and most folks don't even know there is a difference in the chains. There are even special "ripping" chains. Seasoned sawyers know the way to change the tooth cut angle to maximize cutting too. But that gets into a "whole nuther universe"
 
Wasn't aware of different chains for power saws. I'll just dig up some termites and let them go.
hockenbery, is there a reason you don't coat the half log and just the end grain? Thanks.
 
Don Jarvie said:
The sooner you can cut them into blanks the better. If you can’t cut them now keep them dry and out of the sun.
Click to expand...

I gotta strongly disagree with “keep them dry” — put them in a barrel of water or wet them down and cover with a tarp. Whatever you do, don’t expose them to “dry” before you can cut and wax them. Out here in the PNW, sawmills have huge piles of logs that are under constant Rainbird sprinklers to keep them wet and in a humid environment.

A rabbit trail to the where the OP is right now: read up on boiling roughed out bowls. I’d absolutely do this with the apple and probably the cherry to. Fruitwoods can be challenging to get to equilibrium dry without degrading.
 
Last edited:
John Torchick said:
Wasn't aware of different chains for power saws. I'll just dig up some termites and let them go.
hockenbery, is there a reason you don't coat the half log and just the end grain? Thanks.
Click to expand...

Yes. anchor seal costs money. And itisn’t necessary to coat the whole log in regions of the country that have humidity. In an arid region I would coat the whole log and do it before the chain stops moving on the saw.

The end grain looses moisture quickly the face and side grains loose water slowly.
Sealing slows down moisture loss. Sealing the endgrain sort evens out the moisture loss.
If I have a really nice crotch I seal the crotch face too.

Think of wood like a bundle of paper straws when you cut it with a tool and when you consider how it dries.
The water comes out the ends of the straws really fast and comes through the sides very slowly. When the tree was living these “straws” carried water and nutrients up and down in the tree between the roots and canopy.
Not much leaked out through the bark.
 
Not rough turning apple almost immediately is a good way to get wood for the smoker. Cherry is right behind it. Both can start cracking by the end of the day when it's hot. Bugs really like to bore into apple too because the sap is sweet. Ripping chains are when cutting along the grain, starting on the end grain and cutting in. It will just give you speed, any chain will do it, but extremely slowly. I rip parallel to the pith. The saw can clog with long curls, but definitely worth it. It's also a benefit to have the end of the bar out of the wood. Like ripping 17" long log sections with an 18" bar. Having the bar fully inside wood slows everything down. I clipped off the end of the motor chain guard on my Stihl. The chain is not exposed, but was a huge improvement on long curl ejecting. As Perry mentioned, I don't recommend the safety chains either. Also filing down the rakers on standard chains is also a benefit. But both of these suggestions are for people with some experience with a chain saw.
 
SE TN isn't exactly an arid climate.
Owen, I recall driving by a lumber mill in central Florida several years ago. I wondered why they had a sprinkler system on the log stacks. Now I know.
 
I have a ripping chain and use when cutting lots of blanks. It is faster and makes a clean surface.
For doing a couple of blanks I don’t switch chains.

I do not recommend a ripping chain for 3 reasons
1. They are supposedly more prone to kickback and should be used only by experienced folks.
2. They add little value for the average turner.
3. Anyone who is experienced enough to use a ripping chain will have already decided if they want one.

My experience with Apple and cherry vary a lot.
Apple wants to move a lot. Turn thin an let it do its thing.

Most cherry I have gotten ( Maryland & Florida) was fairly stable - with one notable exception- a bunch of club members got a huge cherry 4’ diameter growing A few hundred feet from the Chesapeake bay. everyone had trouble with cracking from that tree. Sapwood was maybe 3-4” thick which may have contributed.

I had a bowl form that tree that while it did not crack it warped so severely that it looked more like a saddle than bowl. We all just decided it was a rogue tree that did not behave like any cherry we had seen.
 
In one of the videos that I checked out yesterday the guy was cutting with the top of the chainsaw ... in other words, he had the bar completely buried in the log and was cutting from the bottom up. I guess that he has been lucky so far, but the danger is that the saw can get kicked back out of the wood and hit him in the face.
 
Bill Boehme said:
one of the videos that I checked out yesterday the guy was cutting with the top of the chainsaw
Click to expand...

Did the guy start the cutting with the top of the bar or just finish the cut with the top of the bar?
I finish ripping from the bottom a lot when cutting in the field to avoid hitting dirt.
I cut through a log leaving the last inch as a hinge then roll it over and cut with the top of the bar to halve the pieces.

I often cut 4ft pieces this way with a 24”bar rip with the bar at an angle that leaves the hinge.
Roll the log insert the bar in the kerf and cut with the top of the bar walking down the log.
The hinge has to be just an inch or the kerf gets packed with chips making it difficult to saw.
 
He cut about 2/3 the way through then flipped the log over, stuck the bar in the kerf level so that the entire top of the bar was cutting. I flip the log over when most of the way through, but then start cutting from the outside. I also rock the saw to minimize clogging the kerf and also minimize clogging the gullets of the teeth. His saw was constantly bogging down and maybe that's what saved him from a kickback.
 
Bill Boehme said:
flip the log over when most of the way through, but then start cutting from the outside
Click to expand...
When i’m out in the woods or someone’s yard the flipped over side will have dirt and mud on it.

You have a better eye than I do - I can never hit my line inside from the outside.
being in the kerf and cutting on top of the bar I hit my line perfectly and most of the dirt goes away without dulling the chain.

If I have my log holder 0E9B1C08-1784-4F10-A09B-1E2DEDD31581.jpeg I just cut all the way through top to bottom.51EC8603-C56B-4B84-802C-A510CE7473E5.jpeg

One thing that clears the long strings is to pull the saw back from the blank so that the bucking prongs are clear of the blank a couple inches. Also when ripping is just let the saw do the work. I hold it plumb and on line and let it cut. My saw knows how fast to go. And a stihl 440 doesn’t loiter.
 
On occasion I have split a few logs using a splitting maul and wedge, this is usually quicker than using a chainsaw and the center of the log being split is where the pith wood is being removed so the stress on the wood is concentrated in the area that will end up being waste. It is nice having a flat surface cut from a chainsaw, but some of the billets I process do not need a flat cut as many pieces I make are a spindle type item which is roughed out on the lathe between centers. Some wood types will split cleanly and easily with a splitting maul or wedge which simplifies the process for those turners that don't have a chainsaw.
 
When you have a 34 inch log and a 20 inch saw. I sharpen my own chains and have for 15 yrs. I also only use Stihl chains. The teeth seem harder and seem to dull slower compared to Oregon, Poulan and Husky. I never had a ripping chain, but I had changed the tooth angle slightly on one chain for ripping and get a much faster cut on green walnut and cherry. I usually only chainge chains when I have three of four logs laying. A friend used a chain saw mill to make the beams for his post and beam house. He switched to a ripping chain and could cut almost twice as fast. But he was cutting 100+ logs.
 
Hmm, I can't remember, but think I have always had a ripping chain rather than cross cut chain, mostly because I do more ripping. I do consider the chainsaw to be the most dangerous tool we use, in part because of all the exposed teeth. I never rock the saw because as soon as I do, that is when I get a far rougher surface that is not even close to being flat enough to put on the bandsaw. I do keep it at an angle rather than directly parallel to the grain so I don't get as much clogging with the shavings, but even if I do, it still keeps on cutting. I have a couple of videos up on bowl blank prep as well as a bunch on basic bowl turning, search robo hippy...

Here is one:
View: https://www.youtube.com/watch?v=-JCwwCxkROw


robo hippy
 
Bill, sounds like New Mexico. That is, if there is a tree for a cow to get shade. Drove for miles from Fort Stanton and Lincoln to Moriarity, NM. Dogs were lined up at the one tree we did see.
I heard that west Texas was like Hell- just needed some water and a few good people.
 
Speaking of water, it's been so hot and dry that I have to prime my throat just to spit. :D

I asked somebody what was the temperature. He said it was 110° in the shade. I said, "In that case I'm staying out of the shade ... it's hot enough in the sun".
 
I know of a cowboy in NM that passed out. They had to throw a bucket of dust in his face to bring him around.
 
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