Turning green/wet walnut

[Greg Parrish]

What's the trick as I've tried numerous pieces and it's a big pain. It's hard but my biggest problem is I can't get it dry without cracks. Thanks for any good pointers.

[Phil Rose]

I love green walnut. One of my favorite woods to turn to very thin finish thickness on the first turning. When I twice turn, I follow standard (for me) process with good luck. Turn thickness to 10% of diameter. Be sure the is near that mark as well. I will dish in the non the help. Then I coat with Anchors Seal all over and let sit for at least a year. FWIW, I am in upstate NY, so your mileage may vary elsewhere.

[John Keeton]

Vessels need to dry from the inside so the interior contracts and slowly brings the exterior with it. If the outside surface of the vessel dries then it will attempt to contract, but the interior is still wet and resists the compressive force. The result is the exterior surface has to crack in order to shrink.

I find that sealing the exterior and rim of a roughed bowl, leaving the interior bare results in nearly 100% success.

[Greg Parrish]

Thanks guys. Will try that on the next one. Still have a handful of pieces to do something with.

[Reed Gray]

I don't turn it any more because it was starting to make me sneeze and itch. It was one of the easier woods to dry without cracking. Turning to 5/16 or so thickness, and only once turned. I did notice that it dulled all cutting edges faster than most other woods. Do round over rim edges.

robo hippy

[Bob Bergstrom]

Walnut can turn very easily or if it has silica in it it will dull your tools quickly. I have experienced both. It is a beautiful wood and the results are worth sticking with it.

[John K Jordan]

What's the trick as I've tried numerous pieces and it's a big pain. It's hard but my biggest problem is I can't get it dry without cracks. Thanks for any good pointers.

One "trick" almost guaranteed to work is to boil the wood. The late Jim King, who for years exported exotic woods from Peru, told me boiling was the only way some of bowls they made would survive. Evidently the heat from boiling softens the lignin in the cells and allows it to dry without cracking. Entire blanks can be boiled or roughed bowls. I haven't tried boiling walnut but it might be worth a try. You can use a turkey fryer with propane heat source - one big safety thing is to not try to boil a bowl that fits fairly tightly in the container - pressure can build up under the piece with serious results. Completely safe otherwise.

Here is a writeup from expert Stephen Russel about boiling.
http://www.woodturningvideosplus.com...reen-wood.html

Stephen also has a wonderful library of articles worth reading, including good info about turning things from green wood:

http://www.woodturningvideosplus.com...-articles.html
http://www.woodturningvideosplus.com...ning-tips.html

JKJ

[Glenn C Roberts]

Phil, What does this mean: " I will dish in the non the help", and "FWIW?" Coincidently, I am currently turning some of that Upstate NY walnut.

Bob, How does one know if there is silica in wood?

[Peter Blair]

Greg, I am having lots of success utilizing a Boot/Glove dryer. I turn to final thickness, leaving a small stub that I can grab with one of my chucks so I can put back on the lathe to sand after drying. I then place on my dryer using the forced air without heat to dry from the inside out. Have been told that the success I am having is because walnut is a fairly easy wood to dry without cracking . . . not what you are experiencing at all. Incidentally using this method dries at about twice the speed of a piece that isn't dried with this method.
I have posted a few more details and photos on my blog.
https://woodbowlsandthings.wordpress...5/drying-wood/

[Prashun Patel]

I have green wood drying success to vary from from tree to tree.

For my money and effort, the easiest is to slather a wax sealer on the wood after roughing it down. Pay special attention to the rim end grain.

When the wood is critical, I'll apply wax for a couple days in a row to the entire bowl. It's not the quickest solution, but for me, it's the easiest. It works *almost* all of the time with any kind of wood.

Oh yeah, you aren't working near the pith are you?

[daryl moses]

you aren't working near the pith are you?

That's a great question. In my experience if the pith is still in it is a guaranteed crack, as are knots.
Now I ALWAYS cut the pith out on any piece. Unless it's an end grain form.

[John K Jordan]

Phil, What does this mean: " I will dish in the non the help", and "FWIW?" Coincidently, I am currently turning some of that Upstate NY walnut.
Bob, How does one know if there is silica in wood?

The only way I know to test the silica content is to try cutting it and see how fast tools get dull. I still have an old mantel plank (supposedly over 100 years old if that makes any difference) that dulled a new bi-metal Starrett bandsaw blade with just a few short cuts.

However, a quick Google search found this from the Forest Products Laboratory:

Silica (SiO2 content in wood can be determined by treating the
ash with hydrofluoric acid (HF) to form the volatile compound silicon
tetrafluoride (SiF4, The weight loss is the amount of silica in the
ash. Silica is rarely present in more than trace amounts in temperate
climate woods, but can vary in tropical woods from a mere trace to
as much as 990. More than 0.5% silica in wood is harmful to cutting
tools.

https://originwww.fpl.fs.fed.us/docu...4/pette84a.pdf

There were plenty of other hits to research.

BTW, FWIW is shorthand for "For What It's Worth". DAMHIKT - if you do, I might say SWMBO told me.

JKJ

[Greg Parrish]

That's a great question. In my experience if the pith is still in it is a guaranteed crack, as are knots.
Now I ALWAYS cut the pith out on any piece. Unless it's an end grain form.

All all good feedback so far. With regards to above, I did have some end grain and maybe the pith. Can't remember and not in front of it. But thinking back at the pieces that cracked I'm thinking the way the person cut them might be part of the problem.

[William Bachtel]

I never have trouble turning Walnut, no cracks not even with the pith in it, in fact Walnut is one of the woods that dries nice with the pitch in it.

[Phil Rose]

The auto spell check in this new computer stinks. I dish the tenon in the middle to help make the bottom thinner. Nother enough to either decrease the strength or not leave enough room to sweeten on the second turning. FWIW = for what it's worth.