Face Plate drying

[Gerald Lawrence]

I do not usually turn on face place ,or at least never this large. This is sycamore bowl 16 inch at first turning. Left it at 1.5 inches thick. Had poor luck when turning a 8 inch of same on chuck. tenon broke off>
1. Can I leave the faceplate on to dry for 2nd turning?
2. I usually dry in paper bags with shavings. No bag that large so is right now on shop floor in a pile of shavings to slow drying. Is there a better way to dry a turning this large?

 

[Dan Oliphant]

Gerald, I didn't see a photo, but no matter. You can leave the rough turned piece on your face plate until completely dry. I suspect that will take quite some time in your neighborhood. Hope you have several more face plates! I know turners that leave pieces mounted to face plates for several years before final turning.

 

[Dennis J Gooding]

Gerald, it will depend on the wood. Many woods will shrink very significantly cross-grain while drying. If you leave the face plate on you are likely to develop cracks in the base. Something has to give.

Dennis

 

[Bill Boehme]

It would be best if the faceplate is stainless steel. Heavy anodized aluminum are second best. Some aluminum faceplates are not anodized and can corrode badly if left on green wood. Steel and cast iron can also rust a lot on green wood. Use deep thread stainless steel screws.

 

[Gerald Lawrence]

Gerald, it will depend on the wood. Many woods will shrink very significantly cross-grain while drying. If you leave the face plate on you are likely to develop cracks in the base. Something has to give.

Dennis

This was the consideration I had in mind. Had no idea if that concern was realistic. Since the tenon shrinks out of shape Thought it might make the connection out of round , cracking is the interesting possible I had not thought could really happen.
Thanks for the comments. Oh by the way I did take pics with phone just cannot get them on computer right now

 

[Bill Boehme]

I've never experienced cracking from leaving a faceplate attached while wood is drying. That doesn't mean that it won't. I think that there are many things that can affect the outcome of leaving the faceplate attached.

• Wood in this part of the country isn't as wet as wood in the Pacific Northwest so there is less warping during drying.
• different species of wood shrink differently during drying.
• Face grain vs. end grain orientation makes a difference.
• Diameter of the screw circle is bound to be an important consideration.

I am cautiously skeptical about faceplate induced cracking being a problem, but that is just my opinion and nothing more.

 

[Gretch Flo]

sycamore dring

My limited experience a long time ago is that sycamore really warps. On a 16" piece and 1 1/3" diameter, may be cutting it close after removing the warp and end up with one piece!!!!, Gretch

 

[Odie]

As a dedicated faceplate turner, I prefer roughing nice pieces of wood for seasoning bowls in a chuck. The obvious reason for this is you don't have to use screws in that fine piece of wood. Gerald, I have to ask why your tenon broke off. With the exception of excessively deteriorated pieces of wood, there are only several reasons why the tenon can break away......and, they all have a fix. The reasons are not tall enough tenon, too much bite being taken with the lathe tool, or a catch. Not having as sharp as possible tool could come into play as well, since they will resist the cut, consequently creating more force in the roughing process. However, even if the tool isn't as sharp as it could be, it still can be done by taking smaller passes, or bites.

I have had a tenon break off in the past, but I don't think it's happened in the last decade. The fault was always the circumstances I created in doing it.....not the general method in itself.

It's true that the roughed bowl will warp, or become narrower across the grain, and this applies to a lesser degree with the small overall space included in the tenon. Not only will the tenon become narrower across the grain, but sometimes there will also be a slight curvature to the very bottom. I usually mark the location of the third jaw, so that it's in the same place when re-mounting. If the curvature is significant, it will also be necessary to rock the warp slightly in the jaws, so that the deviation is equal on opposite sides before tightening the chuck.......this will position the bowl so that the least amount of waste is required for the final turning.....(or, in my case, preparation for mounting the waste block.)

ooc

 

[Bill Boehme]

As Gretchen said, sycamore warps more than average and at 1.5 inches thickness you might run out of wood trying to get back to round. Keep an eye on the warp and consider finish turning before the wood is completely dry and be willing to accept some warping if necessary.

With sycamore, I think that coating with Anchorseal is the best method for drying slowly with the least cracking/warping ratio[SUP]1[/SUP]. Paper bagging might work, but I don't think that it does enough to slow down the rate of drying. I think that bagging the bowl with shavings packed around it might have just the opposite of the intended effect. While the shavings are initially wet and provide a moist environment, that is only a short term condition. Because shaving shavings have a huge surface area compared to volume, they dry very rapidly. From that point forward the shavings behave as a desiccant in the bag with the bowl --accelerating rather than retarding the rate of drying.

[SUP]1[/SUP] Slowing down the drying process is a trade off between cracking and warping. The more that drying is retarded, the less cracking will occur, but at the expense of more warping.

 

[John Tisdale]

I would remove the faceplate

American Sycamore according to the wood database: Shrinkage: Radial: 5.0%, Tangential: 8.4%, Volumetric: 14.1%, T/R Ratio: 1.7

I would remove it from the faceplate - there is nothing to gain with leaving it on and, according to the above numbers, probably some cracks to gain.

On the drying, I would do two things: First - boil it for about 1.5 hours to reduce some/most of the stress and to significantly decrease the drying time - see link to Steve Russell's info below. Second: you can put it in a cardboard box for drying - the total saturation to 20% is the critical phase but, after that, you can be more aggressive. You might find the Eugene Wengert's white paper of interest - while its primary focus is lumber drying, the concepts also apply to us log turners.

After your piece gets down to 6% - 7% (probably 3-5 months), re-cut the surface of the tenon on a jam chuck or Kelton mandrel. Be it large hollow forms or bowls, mounting on a less than perfect surface is an invitation to problems.

John

http://www.azwoodturners.org/boiling.pdf
http://www.lignomatusa.com/images/Docs/LignomatPrinciplesPracticeDryingLumber.pdf

 

[Gerald Lawrence]

logic

As Gretchen said, sycamore warps more than average and at 1.5 inches thickness you might run out of wood trying to get back to round. Keep an eye on the warp and consider finish turning before the wood is completely dry and be willing to accept some warping if necessary.

With sycamore, I think that coating with Anchorseal is the best method for drying slowly with the least cracking/warping ratio[SUP]1[/SUP]. Paper bagging might work, but I don't think that it does enough to slow down the rate of drying. I think that bagging the bowl with shavings packed around it might have just the opposite of the intended effect. While the shavings are initially wet and provide a moist environment, that is only a short term condition. Because shaving shavings have a huge surface area compared to volume, they dry very rapidly. From that point forward the shavings behave as a desiccant in the bag with the bowl --accelerating rather than retarding the rate of drying.

[SUP]1[/SUP] Slowing down the drying process is a trade off between cracking and warping. The more that drying is retarded, the less cracking will occur, but at the expense of more warping.

Bill I will have to respectfully disagree with you on what the chips do. In open atmosphere you may hav a point for thin layer. In heavier layers and when there is an outer covering I believe that they act like insulation. The outer layers will wick moisture out, but the inner layers slow this like insulation does to slow migration of hot or cold air. What my concern was that I cannot leave this in the shop floor and no outer moisture barrier to slow the process even more. You and Gretch may indeed have a point on the warpage factor and this is a big concern for me in this post.

John Tisdale

I would remove the faceplate
American Sycamore according to the wood database: Shrinkage: Radial: 5.0%, Tangential: 8.4%, Volumetric: 14.1%, T/R Ratio: 1.7

I would remove it from the faceplate - there is nothing to gain with leaving it on and, according to the above numbers, probably some cracks to gain.

On the drying, I would do two things: First - boil it for about 1.5 hours to reduce some/most of the stress and to significantly decrease the drying time - see link to Steve Russell's info below. Second: you can put it in a cardboard box for drying - the total saturation to 20% is the critical phase but, after that, you can be more aggressive. You might find the Eugene Wengert's white paper of interest - while its primary focus is lumber drying, the concepts also apply to us log turners.


John I will definately try the box just could not come up with some other than plastic to wrap with. If I can convince wife to let mne try will boil in large kettle we have. In the database info what is T/R?
Again thanks to everyones brainstorming. I was just not set up to handle large pieces in an expedient manner.

 

[John Tisdale]

Gerald,
To address four questions / points:
1) If I can convince wife to let mne try will boil in large kettle we have.
MISTAKE: The crud that boils out will ruin most pots, especially if it is aluminum which is preferred for boiling. Sam's offers pots up to 200-qts. Mine is 140-qts and has a diameter of over 23". If I remember correctly (no guarantee of that), Steve Russell uses a 50-gal drum cut in half.
2) In the database info what is T/R?
ANSWER: Bruce Hoadley's book UNDERSTANDING WOOD is the best investment any of us can make - a deal at twice whatever price you pay. T/R is the ratio between tangential and radial (flat sawn vs quarter sawn). But it is the absolute numbers that are the more critical - it is the % shrinkage that makes wood warp / hardwood floors cup. And thinking you can change those numbers is, at best, presumptuous. An optimum drying regiment can reduce/prevent cracking while minimizing required time - both good things. But the warping will be "what it is" which is also a good thing - I think of it as decompressing or relaxing. My 22"-dia walnut "roughs" are now 22" with the grain, 20.5" across the grain. That's why us rednecks love mesquite - it has: "Radial: 1.6%, Tangential: 3.2%".
3) I was just not set up to handle large pieces
ANSWER: Big stuff takes commitment in room and equipment (and mindset). An occasional "biggie" has to be difficult.
4) in an expedient manner.
COMMENT: When you can do large (20"+ diameter) in an expedient manner, I'll be your first student. "Large" in any sentence with "expedient" is an oxymoron. It took a while for me to understand that - my turning history is a trail of dumb-***/foolish mistakes that both amaze and entertain.

 

[Odie]

It took a while for me to understand that - my turning history is a trail of dumb-***/foolish mistakes that both amaze and entertain.

Dumb-*** foolish mistakes are a requirement. 🙁

lol

ooc

 

[John Tisdale]

Since we're on the subject:

Salvatore Dali put it best:

Mistakes are almost always of a sacred nature. Never try to correct them. On the contrary: rationalize them, understand them thoroughly. After that, it will be possible for you to sublimate them.

 

[john lucas]

I used to turn a lot of bowls on a faceplate before I started roughing them between centers. When I did I only had 2 faceplates so leaving them on was. It an option. Also cracks in my bowls always seemed to be in either the lip or the foot. To solve the problems I made a jig that fits in the faceplate and has a center hole. I put this in the faceplate and put a pointed rod in the hole a d make a centering point In the center of the tenon. This allows me to mount the bowl between centers after its dry so I can true up the tenon to either mount in a chuck or to put the faceplate back on.
With the faceplate off I coat the foot and the lip with anchorseal. I usually put the bowl in a paper sack for the first 2 to 4 weeks. The. Put it on the shelf to dry.
I tried putting bowls in shavings. All it seemed to do was promote mold. I could t tell that my bowls cracked any less using the shavings but sure did get moulds with stains

 

[hockenbery]

I would leave a faceplate on a owl longer than a day or two.
Many bowls I might rough on a faceplate I would finish return on a chuck.
Especially the big bowl I might be coring.

Most often there is large block for the faceplate.

I would mark the center bottom before remove in the faceplate.
I have a turned handle with a nail mounted in the center and a diameter on the nail end that just fits in the faceplate.

Once I have the center marked I would jamb church it and turn the faceplate tenon down to a chuck tenon easier to dry successfully
In the days before I had a chuck I would drill a hole with a 1 to 2" Forstner bit close to the bottom of the finished bowl using the center.
Remember the point of the Forstner will be use to recenter the dry bowl to true the faceplate mounting face
Which I always turn slightly concave so the faceplate sits flat.

I thick this hole relieves some of the stress in the faceplate tenon so the bowl can dry with less chance of cracking
Also I generally turn the bottom of a roughouts thinner than the sidewall to account for the tenons. The bottoms of face grain bowls do not warp much.

Have fun

A

 

[Mark Hepburn]

Salvatore Dali put it best:

Mistakes are almost always of a sacred nature. Never try to correct them. On the contrary: rationalize them, understand them thoroughly. After that, it will be possible for you to sublimate them.

I'm In good company then regarding dumb mistakes 🙂

And John, you always seem to have an interesting and erudite thought in your posts. And Dali is my favorite surrealist painter. Crazy but supremely gifted.

 

[Gerald Lawrence]

Gerald,
To address four questions / points:
1) If I can convince wife to let mne try will boil in large kettle we have.
MISTAKE: The crud that boils out will ruin most pots, especially if it is aluminum which is preferred for boiling. Sam's offers pots up to 200-qts. Mine is 140-qts and has a diameter of over 23". If I remember correctly (no guarantee of that), Steve Russell uses a 50-gal drum cut in half.

ANSWER: Big stuff takes commitment in room and equipment (and mindset). An occasional "biggie" has to be difficult.
4) in an expedient manner.
COMMENT: When you can do large (20"+ diameter) in an expedient manner, I'll be your first student. "Large" in any sentence with "expedient" is an oxymoron. It took a while for me to understand that - my turning history is a trail of dumb-***/foolish mistakes that both amaze and entertain.

Thanks for the advise on the pot. Fortunately it was to small anyway. As you said my personal largest so far . Do not intend to do that many like this. Actually Mark inspired me with his post on a bread bowl, which is the plan for this or some not quite as large 100 year old magnolia. I can see more face plate turning in my future and the shared info could prove invaluable .

 

[Owen Lowe]

Gerald,
To address four questions / points:
1) If I can convince wife to let mne try will boil in large kettle we have.
MISTAKE: The crud that boils out will ruin most pots, especially if it is aluminum which is preferred for boiling. Sam's offers pots up to 200-qts. Mine is 140-qts and has a diameter of over 23". If I remember correctly (no guarantee of that), Steve Russell uses a 50-gal drum cut in half.

I picked up a speckled-enamel 14”(?) canning pot and lid at a thrift store for $2 - maybe it was $5... It’s stained and has a couple small dents but is great for wood-boiling.