I started back turning bowls after a long while

[Mike Davis]

I am much better able to handle large weights and chain saws and subtle turning on the lathe.
I had three logs delivered before I cut my hand, they’ve been sitting in my shop for about two years.
This weekend I cut one into blanks and turned the first bowl. Cherry that was on the ground so long all the sap wood rotted away. I turned the wall to about 1/4 thick. Diameter is 10 inches and height is 4 inches. I tried not to do any sanding but old habits die hard. Just a little 400 grit. This will get several coats of organic flax seed oil and maybe a short oven soak to bring out more color.

 

[ScottM]

Beautiful bowl Mike. You still have your touch.

 

[Wilsoncb]

Nice work Mike, looks like you still got it. I haven’t got into turning yet, but this is a perfect example of why I will some day. You take an old crusty stump and turn it (pun intended) something beautiful. You never know what you are going to get which makes it a trill when it comes out like that.

 

[JNCarr]

Very nice work.

 

[HITCH-]

That's Purdy!

 

[ashley_phil]

very nice work!!

 

[Jim Wallace]

So could you explain a “short oven soak”?

 

[Mike Davis]

So could you explain a “short oven soak”?

I have done it with spoons and it gives a nice 'patina like' dark finish.
Oil the wood, let it dry a couple days, place wood item in oven, turn on to about 220-250 for 30-40 minutes.
Check after 15 minutes and every 5 minutes after that until it reaches the color you like.
Additional coats of oil can be applied while hot and after it cools depending on the gloss and surface texture you like.

 

[Canuck]

Happy to see you back in the saddle, Mike. BTW ...Great looking bowl there!

 

[Chaz]

There's something about turning bowls that is very satisfying, and you do it well!

 

[Mountain City Bill]

Great work! I love turning cherry.

 

[Berta]

That is a pretty one!

 

[Oka]

Nice to see you back in action

 

[Jim Wallace]

Very interesting, Mike. So cooking the wood at that temperature is very close to torrefaction. Lee Valley uses torrefied Maple for the handles of their premium chisels. It’s quite dark - very pretty. In a commercial setting there is a protocol for managing humidity to keep the wood from drying too quickly and splitting. Have you had any trouble with cracking when you cook the bowls in the home oven? Perhaps oiling the bowl before roasting keeps it from drying too quickly. Are there any woods besides Cherry that you have had good results with? Torrefied wood is also used to make guitars.

 

[wndopdlr]

Love Cherry. This log had some nice gum lines in it which add to the beauty.

 

[Mike Davis]

Jim,
I did not know any of that. Baked my first spoon in 1986, it was maple. Still have it and it still looks like the day I made it. Just thought it would be a good idea. No research, no scientific study. Have only cooked spoons so far.

This bowl warped as it dried over night. It was 20% when I turned it. I will oil it and let it dry a few days before I bake it. If it cracks I will know not to try another one.

Thanks for the technical information. Most everything I do is by trial and corrections. I guess I should have taken lessons or gone to school but those opportunities were not available when I started and it seems a bit late to start all over now.

 

[petebucy4638]

A couple of months ago, I turned a 5" walnut bowl with about a 30% moisture content from a blank that I bought at Klingspor. Over the next couple of weeks, as the bowl air dried in the house, it took on a very oblong aspect, but it did so without cracking. Today, the moisture content of the bowl is around 11% and the very symmetrical oblong shape is still there. Fortunately, there were no cracks.

 

[JNCarr]

I dont think wood torrefies at 220-250 F. Add another 100-150 degrees F and get rid of most of the O2.

 

[Mike Davis]

I did a quick search and most of the articles are about converting biomass to fuel similar to charcoal.
I saw a few mentions about guitar wood. Yes, 250-300 degrees in an oxygen deprived atmosphere and the articles mostly said 20 hours.

I would be interested in reading more about this as it relates to woodworking as tool or furniture.

 

[Jim Wallace]

I think the reason to remove oxygen is that many woods will begin to char before they reach 350 degrees. The idea is to harden the wood and stabilize it by driving out moisture without turning it into charcoal. Apparently the torrefied wood used in guitars approximates what happens accoustically as an instrument ages. I wonder if cooking longer at a lower temperature will achieve the same result as heating it to a higher temperature for a shorter period. Many woods will ignite at 450 degrees apparently.

Cooking wood to alter its properties has a long history. Many of us will remember reading the Odyssey in school. Ulysses hardens the end of a wooden stob by sticking it into the cooking fire in order to make a spear with which he can put out the Cyclops’s eye so that he can escape the cave by clinging to the belly of one of the sheep as they are turned out to graze in the morning. I have always thought that was a really big sheep! At that age I didn’t think much about hardening the wood.