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Cracks appearing right before your very eyes!

Odie

Odie

Panning for Montana gold, with Betsy, the mule!
TOTW Team
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Last night, I was roughing out a spalted Ash bowl, and tiny little hairline cracks were appearing at one isolated spot within minutes of the surface passing a visual inspection. I believe I've heard of this happening before from another turner, but I don't believe I've seen it occur this fast. For me, I've seen this within an hour, or so of removing the bowl from the lathe......if I don't anchorseal immediatly after roughing.

I'll be darned if the cracks returned after resurfacing. Now I was getting to the point where the roughout was getting under the 1/tenth per inch rule. The cracks were small, very small.....but, you know how tiny little cracks often mean failed bowls.:mad:

I took some anchorseal and rubbed it in the cracks with my fingers, and finished the rough out. Did a full anchorseal immediately after removing the roughed bowl from the lathe. It appears as this worked, because I can't detect any cracks this morning......but, I know the little buggers are still hiding in there somewhere!

It wouldn't surprise me if I end up losing this bowl, but my hopes aren't dashed yet.......we'll see how it looks after a few months of seasoning it.

This bowl was around 16-18% moisture content.

What do the rest of you do for this?

ooc
 
Sounds like it might be a candidate to soak in 50/50 water - wood glue mix. Soak it, let dry and then finish rough turning.
 
Gary Chapman said:
[I didn't know that CA glue would work that well on green wood.
Click to expand...

It is one of the few types of glue that will work on wet green wood, just as it works quite well on nice moist flesh. The fluids in the wood actually accelerate the cure time.

In order to reduce the chance that the CA will stain the wood, hit it first with a light coat of quick drying spray lacquer. Allow a couple moments for the lacquer to flash off the VOC's and then apply the CA. The lacquer will not go into the tiny cracks, but will repel the CA away from the surrounding wood. When you are satisfied that you have treated all of the cracks, continue turning.

Stuart Johnson said:
Sounds like it might be a candidate to soak in 50/50 water - wood glue mix. Soak it, let dry and then finish rough turning.
Click to expand...

I would not use this because wood glue doesn't cure while it is wet and is weak in tension while curing. The wood glue even if thinned will not be drawn to any appreciable depth because of its viscosity. Wood glue works best for shear loads.
 
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Bill Boehme said:
If I see cracks appearing like that, I immediately hit it with some thin
CA glue.
Click to expand...

Hi Bill......

......and, I have some of the CA glue, too......

Been awhile since I've used the CA, and my bottles might be spoiled by now. I've ruined several bowls with the CA, and am currently having some success using clear epoxy to fix cracks and voids on dry seasoned bowls.

thanks

ooc
 
Bill Boehme said:
I would not use this because wood glue doesn't cure while it is wet and is weak in tension while curing. The wood glue even if thinned will not be drawn to any appreciable depth because of its viscosity. Wood glue works best for shear loads.
Click to expand...

On the other hand, if this phenomenon is from drying stress, soaking will close them, and the curing PVA might develop more strength on pace with the need.

Must be some kind of dry winter OD. Have to say I've never experienced such a thing, though it gets to 25% RH here too often.
 
Gretch Flo said:
This bowl was around 16-18% moisture content.


Isn't it about to dry in the next few days with the moisture that low??????? Gretch
Click to expand...

Probably not, Gretch......

Don't believe I've ever finish turned a bowl with more than 12percent MC, and usually it's 10percent, or less. This could be a reflection of our geographical locations, but I would lose too many bowls through subsequent warping/checking.

I normally use the Mini Ligno-E to get the initial moisture content, and anything above 10-12percent gets rough turned, anchorsealed, and seasoned. I weigh roughed bowls monthly, and normally wait until I get three consecutive months of the same weight......that way I know the MC has stabilized.

ooc
 
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I probably learned that from John J but I also use a spray bottle on the outside of many vessels while I turn the inside. I haven't had the checking problems as much as I have warping from starting to dry. The spray bottle stops that. I'm fast enough now that I don't need it as often.
 
John Jordan said:
Ash is prone to this, particularly in the winter in low humidity. All you have to do is dampen the outside with water until you have finished-easy. 🙂

John
Click to expand...

Thank you for your insight on this, John..........

When I rubbed some anchorseal on the problem area, it appeared to do the trick. The water in the anchorseal probably worked similarly.......so, I will remember this.

Do you know you were one of my "instructors" in the art of lathe turning?

Although I haven't viewed it for awhile, I have a vhs tape of yours, from the mid 90's I believe, that has been viewed repeatedly.......over and over! One thing you stressed, that has been a great help to me is your insistance on good stance, thus allowing for smooth transitional movements of body.

ooc
 
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This being my first post I'd like to comment on how impressed I am with the wealth of knowledge that is shared on this site. I found this thread searching for solutions to surface cracks on a piece of wood that I'm turning. I see that I should get a moisture meter, scale and some anchorseal.

Right now I'm working a lot and my lathe time is limited. It is dry here in the winter. Should I put anchorseal on when I'm done for the day. Or is it better to wait until I have enough time to rough out a bowl be for I start it?
 
James Seyfried said:
This being my first post I'd like to comment on how impressed I am with the wealth of knowledge that is shared on this site. I found this thread searching for solutions to surface cracks on a piece of wood that I'm turning. I see that I should get a moisture meter, scale and some anchorseal.

Right now I'm working a lot and my lathe time is limited. It is dry here in the winter. Should I put anchorseal on when I'm done for the day. Or is it better to wait until I have enough time to rough out a bowl be for I start it?
Click to expand...

James.......

It would be best to wait until you can completely rough out the bowl in one session, then anchorseal.

I can remember a specific bowl (can't remember the species it was, off hand) where I roughed it out and decided to anchorseal the next day.....this one turned out to be a big mistake, because it was cracking up the next day when I got back to it. There have been other bowls where this was not the case, and it turned out to be OK to finish up later.

I now completely rough bowls and anchorseal all in one session......it's my rule! This is not to say that some roughed bowls aren't OK to finish up the next day, but I just don't take that chance anymore. It's better to play it safe than take the chance. You won't know how any specific bowl is going to react, until after the fact. Species, specific grain pattern, irregularities in the wood, thickness, general shape, moisture content.......all of these things are contributing factors, and to know what will happen with any specific piece of wood requires a good crystal ball and a bit of lucky guesswork!

If I am unable, for whatever reason, to finish roughing a bowl out, I anchorseal, and finish up later......but, that scenario rarely happens unless something unforeseen interrupts progress.

These days, many bowls are roughed in about 15 minutes, but never any longer than about a half hour.......

ooc
 
I only use Anchorseal on the ends of freshly cut green logs or chainsawed blanks that still have a lot of moisture if I won't be turning them any time soon after cutting them. I suppose that it could also be used on the exterior of rough turned bowls, but I never do use it for that.
 
James Seyfried said:
Thanks Odie!

Bill, what do you seal them with? Or are they less apt to check after they have been roughed out and dried properly.
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Well, I should have added that most of the wood that I turn is not very susceptible to cracking -- mostly I turn mesquite. Otherwise, I usually turn the wood only after the moisture content gets fairly low and then turn the wood to completion in one session. Sometimes I may go back a week or so later and do a light final pass.

If the wood that you are turning still has a good bit of moisture, be sure to keep it wet. Spraying with water after a crack has developed isn't worth anything. A crack is still a crack no matter how narrow. Making a crack swell shut with water doesn't fix anything because a crack can't heal itself and grow back together.

If you need to stop for a while, put the turning in a plastic bag to keep it wet -- this is good for a few hours, but not for days.
 
If I have to stop for some reason while turning green wood I completely cover it with a plastic bag. That seems to hold it just as is. It doesn't warp or crack. However it will mold if left there very long. I generally only do this overnight at the longest if I can. I also work full time and even though I'm pretty fast at turning sometimes things come up and you simply have to leave it.
 
Just another perspective. I don't turn that much green ash. However, I do turn green maple, cherry, and walnut. Sometimes, I spritz the turning while it is on the lathe then just set it aside when I finish (usually wall thickness is less than 1/4 inch, 25 mm, the thinner the better). On occasion, I've seen splits occur in the vessel. Following advice from David Ellsworth, I tend to just leave it alone. After a few days, the cracks generally just close back up and you just don't see them unless you know where to look.

If the crack is visible, then sand first, then apply a first coat of sanding sealer (I usually use shellac). After it dries, lightly sand and fill the crack with dust from the turning and spread some thin CA. The shellac prevents the CA from staining the turning.

As I said before, this is just another perspective. If it works for you, it's yours.

Matt
 
cracks

Lately I have had some cracks develop (crab apple, including a wind "shake")and then close, doing nothing to them.I wonder if CA would actually prevent that, or at least make the crack more visable. Hmmm-what to do???? Another ash bowl that had cracks on ea end of the log was turned , hopefully turning away the cracks. Spent 2 hours completely finishing and sanding the outside, and when 3/4 down the inside I saw a tiny crack develop at the rim. I decided to quit, set it on the floor and watched the crack develop-went all the way to the bottom, and as the days went by before I threw it in the wood stove, it became a 1/4" gap!!!. The cracks were already there when I started-just couldn't see them but was suspicious. Oh well, Gretch
 
often they close when dry

From my experience, often these small cracks will close and be essentially invisible when dry and the piece is finished. Not always, but this often happens

The CA solution works to "glue" the cracks, but then they cannot re close, so it is a bit of a trade off.

As for anchor seal, I find I only really need to coat the end grain. I took Al Stirt's advice, and cut my anchor seal 50/50 with water. Allows the piece to loose water vapor a little quicker.

This has been a great thread to read.

Ed
 
Yea bit Al lives in the frozen north. We have to do all we can to keep the log from losing moisture down South. I have found parrafin wax works better for me than end grain sealer. I think it blocks even more moisture transfer.
 
I have experienced the same issue turning endgrain red oak due to the open grain structure. Since the very nature of the checks developing is not drying, but uneven drying. Generally the faster a piece dryes the more uneven the drying process will be. Whatever stratagie you use need to address that issue. Since your cracks are fine and on a rough turned piece I would suggest the following process.

Soak the bowl just long enough to get the cracks to close up, use spray lacquer to cover surface of bowl, apply then CA to all cracks, then sand off laquer in areas that are not covering endgrain, cover endgrain areas with sanding sealer or something to slow down drying in those areas. Then place rough turned bowl in closed paper bag. The paper bag will prevent air movement over the piece but will still breathe. As long as the bag remains closed, it will force the piece to dry more slowly and thus more evenly.
 
john lucas said:
If I have to stop for some reason while turning green wood I completely cover it with a plastic bag. That seems to hold it just as is. It doesn't warp or crack. However it will mold if left there very long. I generally only do this overnight at the longest if I can. I also work full time and even though I'm pretty fast at turning sometimes things come up and you simply have to leave it.
Click to expand...

A similar technique I picked up in a Brian McEvoy video- wrap the piece with cling wrap if I can't get it finished and it has to set overnight.I have good luck with this here on the dry side of Washington....
 
Ditto w/ plastic bag or saran wrap for temporary holding.

Cracks might seem to close, but they surely don't heal themselves and disappear. You might be passing on a crack to a buyer of your work that might show up later in the inevitable changes in environment the piece goes through.

Re: anchorseal type products--Even in my shop at +/-40RH, anchorseal coating an entire roughout will delay drying to the point of extreme patience! I have had some wood (crabapple) that never even seemed to dry at all after 6 months coated in AS. Paper bags have been my way to go. They slow the drying at just the right speed for my shop climate where I store my roughouts. You want to slow drying, not merely stop it in its tracks.

P.S.- CA glue is the way to go if you first somewhat seal the wood from the glue penetrating and discoloring where you don't want. I use spray dewaxed shellac. I have had the best results with a medium product: it penetrates the cracks and bridges just enough but does not unduly seep into the endgrain.
 
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Been following this to try and track what the problem might be. It's not one I have encountered, and I do live in the frozen north where EMC percentage is around 4 right now. I also turn red oak. Are you folks talking about roughing outside and waiting to remove the in? Are you talking about heat checks developed by too-close lamps, riding bevels (which also flexes thin stuff) and sanding green wood? Or are you talking about heartwood which often has checks or incipient checks due to drying inside a wet shell?

Always a bad practice to walk away from a freshly exposed outside before reducing the in. This can even come into play with the ten percent "rule" if the bottom of the piece is left too broad. The piece in question needs full moisture support, not just topical spritzing. Anchorseal will allow moistening from within, so it's a good choice, as are full occlusive wraps. Best thing is to clean out the center. Takes maybe 10 minutes tops to hog out the waste from a 16x8, which is probably close to the time it would take to locate and apply any other remedy. Can't see that as being an impossibility, unless SWMBO is hollering to get upstairs NOW.

Heat checks are rather easily avoided as well. Don't press. Develops more heat from friction, makes mechanical stress a player if the walls are thin. I have seen people working the inside of a piece, levering that heel of the sacred bowl gouge around the curve so hard they crack the outside. Not heat, but mechanical stress.

I suspect most of the problems are the third category - preexisting or predisposed weaknesses. That's why they will look closed if you wet them from the outside, even though the interior is still pretty well loaded with moisture. And why red oak and other woods with well-developed ray structure will open along those built-in planes of weakness. It's also why what appears to close is still there. Was when you started, will be when you finish. Bit of glue? Never has prevented a drying check from developing further on the end grain, in my experience. Too much mechanical stress from the contracting interior acting on it. Thin will allow more rapid equalization and may hide the crack visually. Basically, when the wood contracts, it doesn't make a difference how you try to contain it. It will contract.

Cranked tight and overnight. Yes, it appears to be red oak.
 

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MM, I think different situations are being discussed. I resurrected this 2-year-old thread with more of a beginner question because it was discussing cracks. I have done some turning on my tube craftsman lathe that I’ve had for 30 years. Now that I have a new lathe (and some better tools) I’m progressively turning larger bowls. I’m working 12 hrs a day and only had a few minutes and rounded off a waxed piece of purpleheart that I bought last year. The next day it had surface cracks; I thought maybe it was because it still had wax on the ends and drying unevenly. When it was cracked the following day after roughing the outside and removing the wax I searched here for a solution. I had a feeling that it wasn't a good idea to start working on it, but didn't know why. I also couldn't resist starting my new lathe up.

So now I know. I have a moisture meter on order and I'm still looking for a scale. Ten or twenty minutes might be enough time to do some sanding and finishing but not for starting a project. If that were all the time I have I’d be better off sharpening some tools or clean up the shop! I should be using my chain saw to get free wood to turn. All the advice presented here sure will be helpful turning green wood.

This site and others sure have been helpful in learning proper techniques, making turning much more enjoyable. I have also joined a local chapter and the AAW to utilize their resources and experience to learn turning.
 
Thanks for the fill-in. Full protection as you would give any full-thickness piece of fresh wood, then. Though end checks are largely self-limiting, they tend to limit at over an inch deep, which is usually enough to ruin the piece, unless it's on the end of a log where there's plenty of room.

I have gone a day or two with green wood buried in the wet shavings. Sometimes I'd get paged out and come back too late or tired to do any more, but more than a couple days was asking for it. Be sure and take it off the chuck if your anti-rust coating is compromised. BIG rust from woods like oak or cherry. Helps if you remember to brush off the ways before you head out, too.
 
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