How much moisture content......

[odie]

.....will you dare to finish a bowl at? Or, does it depend on the size, and species of wood? Give me an idea of your maximum.

Or, are you using a moisture meter at all, and go by a time guide after roughing a bowl?

I am using a Lignomat Mine-Ligno E to test moisture content. Anyone else using this meter? This one is about 15yrs old.

....odie

Here's a pic of the Mini Ligno E:

 

[MichaelMouse]

I finish turning when the piece is at equilibrium. Does involve looking ahead a few days, but if I have doubts I weigh the next weekend's victim, then again three or more days later. If it's lighter in relatively constant humidity, I don't mess with it. I finish as in apply a finish as soon as I detect a change in dimension on a turned piece. That tells me I'm at or below the FSP

Don't own a meter for two reasons. First is that the information it gives me, even if accurate, is essentially worthless. I wouldn't get a piece dryer than its environment, even if could. Second, meters are designed to measure along the uninterrupted grain. Only place there's any of that is in the mortise, and I store bottom down so that the bottom is damp and under compression for as long as possible, so that's the wettest spot.

Actually there's a third. When I need one to evaluate purchase of flat stock, I can borrow one. Tough to weigh a 100" board, and I don't care to do the destructive test which would be the only one to give me valid results.

 

[odie]

Thanks for the reply MM.....

Let me ask you....what kind of scale are you using? How fine an increment does it need to be? How often do you weigh, and how do you know when you've achieved equilibrium?

Pardon me for all the questions, but, as you can see, I'm a NOOB around here. I've been turning, off and on, for about 25yrs, but all my knowledge is first hand.....I've never communicated with other woodturners before.

What does FSP stand for?

....odie

 

[hockenbery]

odie,

I use a meter similar to yours.

I rough turn bowls to 1-1.5 wall thickness and leave the chuck tenon on. I measure in the center of the tenon with the pin meter.

I finish turn bowls when they reach 10% moisture content which is about as dry as they are going to get for me.

I have turned a few at 12%. They still look round years later.

happy turning,
AL

 

[Mark Mandell]

Odie,

Let your house tell you.

Take your meter and check the MC of a framing member, joist, stud, jamb, or a piece of furniture. That will give you the EMC "standard" for your location. Doesn't matter the wood or its density (so long as your meter can adjust) because all "dry" wood in the house, whether it's maple or pine, will eventually have the same MC.

When your roughed bowl gets within 2% of the House EMC, go ahead and finish turning it. You'll be fine.

 

[MichaelMouse]

What does FSP stand for?

....odie

Looked in "while the glue dries" as someone is fond of saying. FSP is the Fiber Saturation Point. That's where the wood has lost almost all the crevice-filling unbound water, and begins to lose water which was formerly bound to the cellulose. Shrinkage begins there, so it's the first point of concern for a turner and turning. EMC is Equilibrium Moisture Content, which recognizes that wood will readsorb atmospheric moisture or lose it to gain equilibrium with the Relative Humidity (RH). EMC is the second point of interest. Your humidity gage will tell you what your EMC is within a point or two.

Get on over to http://www.fpl.fs.fed.us/ and grab the Wood Handbook if you're broadband. Also tech pub 113, I believe. You'll find it in a search for "drying" lumber. If you're dialup slow, get chapter three of the Handbook as a mnimum. It has a lot of pertinent information and data on a lot of woods. Good place to confirm some things you've noticed already and develop an understanding of how they happen.

 

[Hugh]

Odie,
I use a kitchen scale - eletronic type. Reads in both grams and pounds/ounces. I "borrowed" mine from my wife's kitchen. It is now stored in my shop. My wife comes out to weigh stuff once in a while. Purchased at a kitchen store - about $40 - $50. Weighs up to 11 pounds. If you weigh a rough turned bowl for a few days and it is the same weight each time - it is ready to put back on the lathe and return, finish. When I rough out a bowl, I weigh it and write the weight right on to bowl.
Hugh

 

[odie]

Odie,
I use a kitchen scale - eletronic type. Reads in both grams and pounds/ounces. I "borrowed" mine from my wife's kitchen. It is now stored in my shop. My wife comes out to weigh stuff once in a while. Purchased at a kitchen store - about $40 - $50. Weighs up to 11 pounds. If you weigh a rough turned bowl for a few days and it is the same weight each time - it is ready to put back on the lathe and return, finish. When I rough out a bowl, I weigh it and write the weight right on to bowl.
Hugh

Hey, thanks for all the replies gentlemen......

This is great! I should have found this forum a long time ago! I can see this is the place to get some advice, tips, new techniques and whatever.

I believe I'll look around for a scale. I've always used the Lignomat moisture meter, but I'm game to experience a few new methods. Have any idea where I might find the appropriate scale on the internet?

At what rate do you see differences in weights? A few days seems like a pretty short time to determine a stable weight suitable for finishing. For myself, I've been in the habit of leaving roughed bowls out for several months before I finish them. Do you find that stabilizing can occur within a few days after roughing them?

I've used some kiln dried woods. On those, I can usually go from the block to finished in one sitting....but, they're all 3" thick, or less. Air dry is something else entirely, though. I've been in the habit of taking my time with those.

I have a piece of Koa on the lathe right now, and it's about 6" thick. This block has been in my shop for a couple of years......and, it looks like the entire block may have a stable moisture content. I'm planning on not waiting for it very long, we'll see. I haven't dug out the interior yet, though. As I do, I'll use the Lignomat at a few depths to confirm.

....odie

 

[Richard Baker]

Electronic Scales

Our local post office has two sizes of battery powered "postage" scales for sale (among other items). One weighs to about 5#, costs about $40. Didn't look at the larger one.

 

[Griesbach]

Odie, welcome to the forum. Nice bowls on your web site. I checked your Nam pictures and say thanks for the memories, not all of them good but also not all of them bad either. It's been a long time since I've let my mind take that trip. By the way, Nam 1965, '66 '67.

 

[Marc Himes]

where to get a scale

We get our stamps using the internet (stamps.com). This provided us with a postage scale which is accurate to 0.5 oz we do pay a monthly fee so it is cheaper to but the scale by itself. It works well for bowls as few of them are over ten pounds even when turned green. I also have the same moisture meeter and find that it tends to correlate with the weight fairly well.
I have also have the chance to turn wood which was in blanks about ten years old. There still was a fair amount of warping despite the wood being dry. This may be due to moisture changes or release of stress in the wood. You may consider leaving the pieces from the older wood thick and doing the final turning after they have had a chance to equilibrate. Good luck.

 

[MichaelMouse]

At what rate do you see differences in weights? A few days seems like a pretty short time to determine a stable weight suitable for finishing. For myself, I've been in the habit of leaving roughed bowls out for several months before I finish them. Do you find that stabilizing can occur within a few days after roughing them?

It takes time to get to EMC. The weights are done on a piece that should be dry, where three/four days and not more than a couple grams change in 3# is dandy. Piece might have been there for a couple of months at nearly an inch thick (cherry), for instance, or only a couple of weeks at half to 3/8. Worth a look. Don't waste your effort weighing a freshly turned piece. When you weigh, note date/weight as long as you're there. The one you recorded and rejected a week ago might prove to be at the point where you turn when you check again.

I'm now an advocate of blasting unbound water after rough turning. No need to have it there encouraging mildew and discouraging loss of unbound water.

 

[odie]

Odie, welcome to the forum. Nice bowls on your web site. I checked your Nam pictures and say thanks for the memories, not all of them good but also not all of them bad either. It's been a long time since I've let my mind take that trip. By the way, Nam 1965, '66 '67.

Griesbach.....

Thanks for the compliment. I feel welcome. Looks like a great bunch of turners on here.....but, I've always felt turners were a great bunch, happy to share and tell of their experiences. I've been a "lone wolf" for a long time....anxious to get some input from a few other turners.

About Vietnam......well, yes, I suppose we all have good and bad memories of that time. It's too bad so many of us never took any pics while we were there.....I was one of the lucky ones that did. Thanks for your service as well.

....odie

 

[odie]

Holy Smokes, gentlemen.....

I just purchased a digital 35# postal scale on ebay for $1.25 plus $16.88 shipping. Yep, you read that right.....a buck and a quarter! The scale is in .01oz increment.

After this thread I expected to pay more than that. I'll bet there is a glut of postal scales on the market right now. This might be the time for some of you who've been thinking about a scale, to get one.

Run a search for "scale" on ebay. There are plenty of them there that are selling for very cheap.

Here's a link to the auction I bid on:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320064183520

Check it out......and tell me how I did.

....odie

 

[Mark Mandell]

Odie,

Honestly haven't needed a scale that sensitive since college

 

[odie]

Odie,

Honestly haven't needed a scale that sensitive since college

Oops! Good eye, Mark.

That should have been .1oz increment.....not .01oz. My mistake.

....odie

 

[John Nicholas]

Scales and Weights

I use a hanging scale that goes to 20 lbs. I hang it in the garage and have a piece of masonite hung from the bottom of the scale with some chain.

My first piece was a 19 inch platter. Rough turned 1 wk after the tree was cut (April 29, 2006. Wt: 18# Weighed periodically 14#8 oz 7/21 then 12# 14#9oz on 8/27. Mounted and turned 1/4 inch of bottom. Wt: 13#13oz. 9/2 same wt so take another quarter inch off and wt is 12-0. 9/8 wt is 11-13 9/16 11-12; 9/24 wt 11-6. Take another quarter off wt is 10-9. 11-13 wt 10-4. 11-27 wt 11-14.

It seems to be now at EMC. I have worked it regularly since. It is not moving as I work over the month. No cracks. This was maple.

I have some pine cut fresh 8-20. I rough turned bowls all during Sept. They have stopped losing wt by 12-16. wkly wts.

About a 40 % wt loss on the maple. The pine lost about 40 - 50 %. I picked up another Maple cut 11-11. Will be interesting to watch the fall cutting difference.

John

 

[woodwish]

My memories of Nam were no where that nice. I keep thinking I should go back like a lot of my friends have done, but I just can't do it. Never took a picture, but my memories will never fade . . .

 

[Bill Boehme]

........ You may see pics of my shop at the following URL .......
http://pic50.picturetrail.com/VOL431/781008/14401334/215839277.jpg

How did that car get in your workshop??

Bill

 

[odie]

My memories of Nam were no where that nice. I keep thinking I should go back like a lot of my friends have done, but I just can't do it. Never took a picture, but my memories will never fade . . .

Woodwish.....

My apologies. It has never been my intent to stir up bad memories for you, or anyone else. Certainly, I have a few myself. I have nothing but respect for those of us who met their responsibilities with a sense of duty.

As you, I wouldn't want to go back either.....but, I will always maintain a sense of pride for the men whom I served with, for their service, and for the objectives we pursued. Those objectives may have been idealist, but none-the-less were an honorable pursuit.....just like our boys now in Iraq. When they come home, they will get the respect they deserve from me.

My next door neighbor is now in Iraq.....has about 4mo to go. I really don't care what the politics of it are, he is a man who believes in what he is doing......and I believe in him.

Thank you for your service as well.

....odie

 

[woodwish]

Odie, no need for apologies and please don't think it bothered me to look at the pictures. Your comments about serving couldn't have been said better. I teach high school and I have many ex-students in Iraq, Korea, Afghanistan, and other places not as safe as my home and shop. Each of them deserves a hero's welcome when they return, and I hope we (as a nation and individuals) never forgot that.

Merry Christmas and Happy Holidays!

 

[Malcolm Smith]

Moisture content

I use a scale designed for weighing tanks of refridgerant before and after filling units. They charge for it based on the difference in weight. While it will weigh the largest size blocks of wood one is likely to use, probably up to somethiing like a hundred pounds, the accuracy is that of a very good postage scale. I do use moisture meters but find them useless on first turned bowls as they require inserting in the wood. With the scale, I simply track the weight of the bowls until they stop losing weight, then do the second turning. This seems an ideal system and is probably more consistent than the use of a moisture meter.

Malcolm Smith.

 

[Malcolm Smith]

Moisture content

I have moisture meters but find punching holes not very practical on first turned work. Through a friend I discovered a scale designed for weighing refridgerant which while having postage scale accuracy, goes up to about a hundred pounds. They weigh the tanks before and after use and charge accordingly. I simply weigh first turned work about once a month and log the result with the date on cards. When I have a couple of readings that are the same, the work has stopped drying and is ready for re-turning. This system seems ideal and is very little trouble. I suspect it's also a lot more accurate than using a moisture meter.

Malcolm Smith.