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Chris Tedford
02-27-2009, 11:25 AM
I've been watching a few videos on turning bowls from logs. It seems that they always split the log in two to make there blanks. I know with bigger logs this is to get two blanks. But if the log is only 6" in diameter, is this necessary? Does grain direction matter to the turning process or just to the look? Thanks for your help.

Chris

Tony Bilello
02-27-2009, 11:41 AM
I've been watching a few videos on turning bowls from logs. It seems that they always split the log in two to make there blanks. I know with bigger logs this is to get two blanks. But if the log is only 6" in diameter, is this necessary? Does grain direction matter to the turning process or just to the look? Thanks for your help.

Chris

The way I was taught, many moons ago was to split the log and orient the bowl blank like in my sketch.
The main logic is that the log shrinks the least near the center and the most near the outer part. With the solid base being near the pith where the least amount of shrinkage takes place, we are assured that the base wont split. The bowl itself including the outer edge will shrink and distort a lot especially while turning. Since this area will have the most movement, it will distort while shrinking rather than crack because it has room to move with the interior hollowed out.
Today, turners are using Denatured Alcohol and other techniques that I am not familiar with. These new techniques allow them to put the pith in the middle without splitting.
Hopefully the will be of more help than I am and be able to write a more coherent reply.

Bernie Weishapl
02-27-2009, 11:45 AM
Chris it doesn't really matter except for one thing. The pith in the center of the log. That is where 99% of the cracks start. So when you see them splitting a log down the middle that is what they are trying to do is get rid of the pith especially if you won't be turning it right away. Now don't get me wrong a lot of turners including myself turn smaller logs with the pith in them. The thing we do is to saturate the pith with CA glue to keep it from cracking. I have turned bowls out of small logs with the pith still in and was taught to make sure you try to center the pith on the bottom of the bowl then saturate the pith with CA.

Rick Prosser
02-27-2009, 12:07 PM
As a minor consideration, the grain will look different if you turn "whole log" compared to "1/2 log". (cutting thru the rings instead of with the rings)

Scott Conners
02-27-2009, 12:40 PM
Turning bowls out of a split log serves two purposes - first, it removes the pith, which is the cause of most cracking, and secondly it allows the wood to be turned side grain instead of end grain. This is both for looks and for ease, as end grain is often much harder to work with, being hard to cut and more prone to tearout and other problems.
Either way is possible, many/most hollow forms are turned end grain. They each present slightly different challenges and looks, but there is no one "right" way. If you orient a whole section of log with the bark parallel to the ways, you're turning end grain, and you're going to have the pith in the center of the bottom of the bowl. Generally, this requires some sort of extra work to stabilize (glue, boiling etc) to prevent cracking. Orienting them like Tony showed (I usually put the foot to the bark side to maximize bowl size) allows the pith to be turned away, and I have much more success this way. Some woods look much better end grain (norfolk pine for example) and I have seen beautiful end grain bowls. Try both, and see which you prefer.

Chris Tedford
02-27-2009, 2:03 PM
Thanks for the info. We just got some fresh cut trees (cut Wednesday) for a theater production we're doing and the boss is willing to let me take the parts I want. We're both kinda wood junkies, I recently helped him split a 24" dia. x 4' long log of Red Oak. That one was nice and wet. Again thanks for the info.

Chris

Jeff Bower
02-27-2009, 2:53 PM
Chris, I found this pdf (http://maubow.weebly.com/uploads/5/3/5/5/535563/bowl_blanks_from_log.pdf) a while ago...Has helped me quite a bit.

Chris Tedford
02-27-2009, 5:48 PM
Thanks Jeff, that is a really useful PDF. I'm much more of a visual learner and that is just what I needed.

Chris