Questions for the bowl turners

[landscraper]

What has been your success rate with turning green bowls and using any of the various drying methods (2 paper bags, alcohol bath, dish soap soak, boiled before turning, etc.).  What do you think is the loss percentage just letting bowls dry on their own without any special treatment.  Does waxing or oiling a fresh turned bowl retard the drying process and help or hurt your chances with cracking.  What does "green" mean for you - fresh off the stump? air dried?.  Do you kiln dry any of your blanks?

Thanks for any info.

[Den-Den]

What has been your success rate with turning green bowls and using any of the various drying methods (2 paper bags, alcohol bath, dish soap soak, boiled before turning, etc.).  What do you think is the loss percentage just letting bowls dry on their own without any special treatment.  Does waxing or oiling a fresh turned bowl retard the drying process and help or hurt your chances with cracking.  What does "green" mean for you - fresh off the stump? air dried?.  Do you kiln dry any of your blanks?

Thanks for any info.

Currently my success rate is about 80% (it took some practice to get there).  I choose among three methods depending on the wood, time of year and whim: 
*  Turn the bowl to finished thickness while green - it will dry in about a week, almost 100% success rate if turned thin enough and you don't mind warped bowls
*  Rough turn and wrap blank in brown paper - it will dry in a couple of months; gets turned again so bowl not warped, good results with elm, very poor with oak.
*  Rough turn and coat entire blank with AnchorSeal - it will dry in about 6 months; gets turned again.  Good results if blank did not have issues.

Slowing the drying rate will definitely reduce cracking but be careful of mold unless you wanted spalting.

Green means (to me) wet enough to spit some water while spinning.  Attempting to dry bowl blanks without at least rough turning them will have a very high failure rate for most woods.  I use the "10%" rule for rough turning (thickness 10% of the diameter), thickness needs to be consistent and the pith should NOT be included.  Any knots will usually cause problems.

[landscraper]

Thanks Den, that's exactly the kind of info I was looking for.  I've been playing around making some little bowls from air dried wood, I hot wax them and microwave them a little at a time every so often and so far no cracks but it's only been a few weeks. 

[Lud]

Den is in Texas and you're in Virginia.  Pretty different conditions for drying I'd guess. 

Here in Ohio,  I cut fairly thick slabs off of logs hoping to square the cant in 4 cuts.  First cut, flip over and 2nd cut, then up on the sides for slightly narrower slabs.  Those 4 slabs get chainsawed to a length that matches their width.  usually will get 30-40 chunks that I take to the Delta bandsaw.  I've made a set of concentric plywood rings that I mount the best fit to the bark side with two screws which gives me a guide and a handle on the block to cut off the corners for a pretty good round turning blank.  Blanks get markered with source and wood type, diameter, and date and then Anchor Sealed on cut surfaces.  They're all stored in the barn in the shade and later they go into the old granary  or the tempering room I built above the granary to enhance stability.

Sure some crack and go to firewood.  The corners are popular with the woodstove buddies. 

Of course I get to turn any blank I want.  I've bagged 1st turned bowls with some success in the hot,  moist months  but I've more often finished the bowl completely and soaked it with mineral oil at slowest speed and in both directions.  Then push the beeswax into the bowl, again in both directions so the micro pores fill.  Then a nylon scrub, both directions at a bit higher speed.  Then a T shirt chunk that has become soaked with the oil/wax mix at higher speeds .  Finally a dry T shirt chunk  at high speeds as a buff...both directions  with enough pressure to feel a bit of heat.  This builds a good finish for me that can be freshened with a wipe of the soaked T shirt chunk and a buff with a towel.  By the way, all the wax, oil and rag in a little bowl and the scrubber and other rags fit in an old cookie tin with a lid so they can be next to the lathe without being contaminated with shavings, dust etc.

Can't think of the last time bowls have cracked.  I do use CA through the turning if I see something that needs stabilizing.  Anyway, that's what works for me out here in Ohio.

[Kasba]

I use the same method as most, the 10% rule. I then completely cover with end seal, leave the blanks on the floor for 6 months and then another 6 months at ceiling height until I am ready to finish turn. Some of the woods I use are not very stable so those I rough turn, then boil and then end seal. The boil method works great and after boiling they only have to finish drying for 6 months before finishing on the lathe. I have tried the denatured alcohol and soap method but have not found to much of a difference other that more cost out of my pocket. Hope this helps.

[pidaster]

Currently my success rate is about 80% (it took some practice to get there).  I choose among three methods depending on the wood, time of year and whim: 
*  Turn the bowl to finished thickness while green - it will dry in about a week, almost 100% success rate if turned thin enough and you don't mind warped bowls
*  Rough turn and wrap blank in brown paper - it will dry in a couple of months; gets turned again so bowl not warped, good results with elm, very poor with oak.
*  Rough turn and coat entire blank with AnchorSeal - it will dry in about 6 months; gets turned again.  Good results if blank did not have issues.

Slowing the drying rate will definitely reduce cracking but be careful of mold unless you wanted spalting.

Green means (to me) wet enough to spit some water while spinning.  Attempting to dry bowl blanks without at least rough turning them will have a very high failure rate for most woods.  I use the "10%" rule for rough turning (thickness 10% of the diameter), thickness needs to be consistent and the pith should NOT be included.  Any knots will usually cause problems.

This is almost my exact methods except for when I seal it (currently using Rockler's Green Wood sealer) I only put it on the end grain areas. I'm in south MS so it's a bit more forgiving with our humidity rates. I have plenty of "green" blanks/slabs  that are a year or more old with over 20% moisture still. I've had a few to crack but not many. This  is how I store them until I decide if they will be bowls or hollow forms.

What is the boiling method? I've never heard of that.

[Kasba]

The boiling method is for wood that is not stable. I start off with a large pot (mine is 20 inches in diameter and 24 inches tall) that I fill with cold water from the tap. I then place the bowls in the pot of cold water and light the heat source under the pot. Once the pot comes to a boil I leave it on a slow boil for 2 hours, after 2 hours I shut off the heat and leave the bowls in the pot until the water has gone back to the temperature from the tap at which point you take out. The final step is to allow to air dry for 3-4 days and then end seal the way you want. The boiling process boils out all the natural water and replaces with the tap water. In most cases you can finish turn in half the drying time as well as boiling takes the tension out of the wood which stops a lot of the cracking and warping of the wood. If you have ever worked with Madrone you will know what I mean. The biggest tip with boiling is make sure you do not use regular steel for the pot as the tannin from most woods will cause you blanks to go black.

[landscraper]

Den is in Texas and you're in Virginia.  Pretty different conditions for drying I'd guess. 

I guess if you mean about drying the blanks or bowls outdoors in different climates - I was thinking more about how the bowls dry indoors after turning. You mean not everyone has lumber and bowls stored in their house to dry?  As far as turning dry blanks I'll kiln dry some roughed in blanks this spring and summer and try it that way too.  Hey, if they go to pieces I'll have an extra cord of very pretty firewood.  I just started to mess around with turning wood on a lathe, not a business or artistic endeavor, merely a winter diversion and I'm enjoying learning about it.  All I've been doing so far is sanding through the grits up to 400 then going to finer scour pads and steel wool until it looks uniformly shiny.  Then I heat beeswax to semi-viscous and buff it in using a progressively finer cloth in both directions until the wax melts under the friction and pressure.  Then I let it cool and I burnish it a fine cloth.   You could count the number of bowls I've turned on 2 hands so this is by no means anything other than me saying what I came up with on my own, and I'm watching the stuff to see how it works.  I microwaved a couple too, heat a little, wait a little, heat a little....  So far my work has been pine, cedar, mulberry and walnut.  One cedar cracked, but it was basically a bunch of knots held together by two wood fibers so big surprise there.  One of the Mulberry bowls warped just a tiny amount around a grain whorl.  Pine hasn't moved an iota, walnut neither.  So far   Most of my bowls are pretty small too - 8" dia. or less.  I told my wife they are bowls for people on a diet.

I made some small bowls for my mom and my sister for their birthdays, told them they had a replacement guarantee if they cracked.  It's not like I don't have a mountain of this wood to keep turning out new ones.  After a few hundred maybe I will figure out what I am doing.  Or I'll have that cord of firewood.

[CHARLIE]

I've used the "soak it in detergent" method and it works fine but the wood is still going to move and go oval after your bowl is completed.

My preference is to put the rough turned wood into a couple of paper bags and then weigh it every week or two.  When it quits losing weight, it is ready to turn.  I enjoy turning lidded boxes and had a chunk of expensive green Quilted Maple.  I used the paper bag/weighing method and while it took awhile, I had no problems with any cracking or changing of shape.

[Left Coast Chris]

For any of you guys that boil, how much color of the wood do you give up?

[Kasba]

I haven't really noticed any change in colour on my turnings but I mostly use Arbutus and Western Maple. My pot that I boil in is stainless so I don't get any tannins from the wood my blanks black.

[Kasba]

What I meant to say was the blanks from turning black caused by the tannins reacting to the iron in the pot.