Green wood turning???

[DaveO]

My research on the subject has led me to the conclusion that there are two schools of thought on the subject.
The first is to rough turn a green bowl leaving it thick about 1" and letting the roughed blank dry (many months) and then finish turning, truing up any warping that may have occurred. This method takes a lot of space and time.
The second is to turn and finish the bowl right away. By turning to a uniform thin wall, you remove the drying stresses that cause cracking. The bowl might deform slightly, but that is considered part of the uniqueness. This method take much less time (although more at one sitting to complete the turning in one session), and seems to me to have a higher level of failure, due to the difficulty of turning uniformly thin walls and bottom.
Then there is the various methods of securing the bowl blank to the lathe. Face plates, waste blocks, chucks, spur and live centers etc.
What I would like to know is: in your experience which is the best method to go with and why?
I am leaning towards the quick and daring method, because I am impatient and don't have the space to store a lot of of rough bowls to dry.

Of course also, there is the discussion on various methods to speed up the drying process of the rough blanks. Big Mike has suggested DNA, and I have read about Penacryl(sp?), microwaving, and tying the bowls to the bumper of your car to increase airflow:lol: :lol:

So I am looking for some.."I did this and it came out this way"...BTDT type info.

Thanks , Dave

 

[michaelgarner]

dave that is out of my area but Im sure intersted in what others say. Sorry I can help friend.

 

[jeff...]

Heck - I've even heard of placing stuff in the cold are return of your air / heat unit (to increase air flow). Honestly I have no clue, but like the DNA approach only because I am somewhat familure with the drying characteristics of DNA.

 

[Big Mike]

Dave, the answers to your questions are almost enough to fill a book or at least a video. I might suggest getting Bill Grumbine's video which is very comprehensive on the subject.

All my bowl blanks are cut round and sealed in anchorseal. I try to turn them fairly quickly as some unevenness in drying can occur and the resultant splitting ruins that blank.

I typically rough turn my bowls green by mounting them on a wormwood screw or screw center chuck. Since I favor the DNA method I leave the wood about 10% of its diameter in rough thickness. Usually that is somewhere around 3/4" or so. A faceplate is probably the safest method.

I use either a tenon/spigot or recess on the bottom depending on how much depth there is to the blank. People will argue which is best and say that the recess will result in more split bowls. I have not had that problem. I have seen many bowls ruined by spigots that were torn off the bottom by a severe catch leaving no way to mount the bowl.

Once the bowl is roughed it is just a matter of soaking in DNA and wrapping as described in the link to Dave Smith's article. Once dry it is just a matter of returning the bowl, sanding and finishing. Almost every bowl in my album and on my website has been turned green and dried with DNA. I have had virtually no failures with the DNA method.

 

[jeff...]

So how long do you have to soak a bowl in DNA?

If you guys need some Ancoseal let me know - I have about 3/4 of a 5 gal bucket full over here. Will be more than happy to send a mason jar full to you via the US Mail.


Thanks

 

[Big Mike]

For the size bowls I turn which the largest are in the 12-14" range on the outside and mostly in the 10-12" range I soak the roughed bowl overnight making sure it is submerged in the DNA. Make sure you are using an airtight container or you will lose a lot of alcohol to evaporation overnight. Some of friends who turn very large bowls, in excess of 16" up to 20", sometimes soak those for as much as a week. Normally I let my bowls dry for a month after the soak but some of the large bowls need drying for much longer.

Jeff, I was recommending the Anchorseal to those gentlemen to seal their bowl blanks while they were awaiting turning. You just paint all areas of end grain prior to turning. If you pre-cut the blanks round on the bandsaw it is a good idea to paint them in entirety. I have had blanks sitting for almost a year painted with Anchorseal which still slung noodles when I roughed them.

 

[JRD]

Dave,

I am a firm believer in the DNA soak method. I've read a lot of articles that dismiss it as nonsense, but can attest that I find it works well for me. Even fruit woods, which I read are notorious for checking. I can not recall a single instance of failure after roughing and soaking before a final turning.

I usually turn to about an inch of thickness, soak in DNA for 24 hours, drip dry, wrap in newspaper, and finish up in about 5 months. After the alcohol evaporates, I've even put pieces in the refrigerator (two or three months down the road) to help speed up the process. Go ahead and laugh, but think about how quickly an unwrapped piece of cheese or meat drys out in the refrigerator.

As for mounting I let the size of the piece and what I am trying to make decide that for me. Large pieces between the head and tail stocks, at times a faceplate and scrap wood block, or with a four way jaw set and wormscrew.

Jim

 

[Matt]

Dave,

When I decided that I wanted to start turning, I joined the Wilmington Area Woodturners Association. Great group of guys and several were kind enough to offer to take me under their wing and teach me a few things. There was only one problem - if you talked to more than one of these guys you would get conflicting information! Some do DNA drying, some do microwaving, some use brown paper bags, etc etc. Enough to make your head swim :drunken_s

I should note that the controversy doesn't end with drying methods. It extends to the proper grind on your gouge, the proper gouge, the proper lathe, the proper wood, toast butter side up or down, etc, you get the idea.

Try some different stuff. Find what works for you and then you can tell that newbie how everyone else is wrong some day...

 

[jeff...]

Jeff, I was recommending the Anchorseal to those gentlemen to seal their bowl blanks while they were awaiting turning. You just paint all areas of end grain prior to turning. If you pre-cut the blanks round on the bandsaw it is a good idea to paint them in entirety. I have had blanks sitting for almost a year painted with Anchorseal which still slung noodles when I roughed them.

Mike I coated all the surfaces with Ancorseal as soon as they came off the mill. I really didn't expect them to sell as fast as they did. I understand it's a good idea to end coat boards, and try to when I can. But this is the first time I ever milled any turning stock. so I figured it wouldn't be a bad idea to seal it entirely all in wax. I hope I didn't mess something up by doing that?

 

[DaveO]

Dave,

When I decided that I wanted to start turning, I joined the Wilmington Area Woodturners Association. Great group of guys and several were kind enough to offer to take me under their wing and teach me a few things. There was only one problem - if you talked to more than one of these guys you would get conflicting information! Some do DNA drying, some do microwaving, some use brown paper bags, etc etc. Enough to make your head swim :drunken_s

I should note that the controversy doesn't end with drying methods. It extends to the proper grind on your gouge, the proper gouge, the proper lathe, the proper wood, toast butter side up or down, etc, you get the idea.

Try some different stuff. Find what works for you and then you can tell that newbie how everyone else is wrong some day...

:rolf: :rolf: Hence my inquiry. I have gone through every website, reading of every method...and everyone is different. Lucky, I have enough stock of this green wood to try all the different methods, but I am impatient and want the gratification of getting it right the first time.

Dave

 

[DaveO]

Mike I coated all the surfaces with Ancorseal as soon as they came off the mill. I hope I didn't mess something up by doing that?

Jeff.. you did perfect. Once they are cut they will need to be sealed again, but you have no idea what size we would want to do it ahead of time.
If you start to sell blanks cut them square and seal all surfaces like you have done, and that is all that is expected of you.
Thanks again for the opportunity to try my hand at green turning...if I get a sweet bowl out of it I'll send it your way :icon_thum

Dave

 

[Big Mike]

Jeff, you did exactly the right thing. The anchorseal will be removed during the turning process. If you prepare individual blanks it is important to coat all of the exposed end grain. The blanks will last longer thus prepared.

Dave, you should have turned some roughs by now. Where are the pictures????? Slack, mighty slack.....:rolf: :rolf: :rolf:

 

[jeff...]

If you start to sell blanks cut them square and seal all surfaces like you have done, and that is all that is expected of you.
Dave

ok so if hear you correctly your saying cut them square. in this case they were 8x8-36

Would it have been better to cut them 8x8x8? In your case you wanted them resawed in half making two 4x8-36's. What I think I hear you saying is your going to further "cut them square" making the face 8x8 the side 4x8 and the end 4x8? This is where I get a little confused, is it square along the face, the side or the end? I'm thinking it's square along the face, else you wouldn't have asked me to cut them in half long ways. But you know with an 8x8, a side could be a face too. When you resaw a 8x8 in half your actually making one face a side that's 4" and the face will still be 8" :eusa_thin. Cutting turning blocks is way more confusing for me than lumber :eusa_doh:. I hope you all can help me understand a little better, so I can know what I'm talking about and be able to communicate better...

The blocks could have been 10x8, but when I don't really know what I'm doing. I make mistakes and learn from them. I figured I would cut them at 8x8 and see what happened, why I don't know, it just sounded good at the time.

Next time I cut some turning blanks, maybe it would be better for me to provide face / side and end measurements? Also it's sounding like it wouldn't be a bad idea to throw a little jar of Ancorseal with each block too?

Thanks

 

[DaveO]

jeff...I turn face grain bowls, so I would want the blank to be 8" square on the face grain side. The side and end grain thickness can vary. I wanted you to split those cants in two because I only have a 6" capacity on my bandsaw to then cut the squares round. Turning blanks can be of any size, generally having one face square is most efficient because that is the least amount of wood removed to make it round. Many people turn end grain, so that could be the square face.
Clear as mud, right :icon_scra:icon_scra

Dave

 

[jeff...]

jeff...I turn face grain bowls, so I would want the blank to be 8" square on the face grain side. The side and end grain thickness can vary. I wanted you to split those cants in two because I only have a 6" capacity on my bandsaw to then cut the squares round. Turning blanks can be of any size, generally having one face square is most efficient because that is the least amount of wood removed to make it round. Many people turn end grain, so that could be the square face.
Clear as mud, right :icon_scra:icon_scra

Dave

Yeah clear as mud!!! But believe it or not I'm starting to see the light. Some folks turn face grain and others end grain. So what's better square face or square end grain? Or is that more of a personal prefrence?

For a square end grain I think I would need to make a special jig for the wood mizer to hold the cant vertical so I could saw it off with the face grain. Either that or get a big honking chop or cut off saw. I guess I could use my chain saw but that wouldn't be very flat and pretty rough. Baileys sells a cut off tool for the chain saw called the beam boss but it requires the tool guide to be held in place with nails or screws and I know no one wants holes in their blanks.

Right now I'm really limited to square face grain.

Thanks for the info on the band saw height capacity. By making any block over 6" thick, I'm limiting myself to folks with bigger band saws (woodguy :lol. I'll keep this in mind, thanks :icon_thum

 

[Big Mike]

Jeff, some turners, not me, turn hollowforms which can be turned with the end grain running parallel to the lathe bed. Most bowls, not all, are turned with the face grain turning perpendicular to the lathe bed. Most bowls have two areas of end grain and two areas of long grain as the wood revolves, er, spins on the lathe.....

Here is a little bowl 2 3/4" in diameter turned with the grain running top to bottom which should be evident in the picture....