Spalted maple -- turn green, or let dry first?

[Jamie Straw]

I went with an OPCAAW group Saturday and picked up a bunch of downed maple, some of which is richly spalted. Have rough-turned 3 bowls, but wondering if there would be any advantage in letting it dry before turning.

 

[Odie]

Hi Jamie.......

If your roughed bowls are warping more than you'd like, then letting a turning block dry prior to roughing/finish turning, will tend to warp less.

The answer depends on the individual pieces of wood, what you expect will happen, what you want to achieve, and all mixed with a little hope and guesswork based on the indicators you have observed.

Some turners look forward to warping......some don't.

ko

 

[john lucas]

The big problem with letting a bowl blank dry is that it takes a very long time and there is a very good chance it will crack and you either lose it or you have to change the shape radically to cut out the crack. I have sealed blanks entirely with wax and been pretty successful at saving them but even after a year they aren't dry. they will warp less because they do lose a lot of moisture during that year. I don't really go out of my way to save bowl blanks. I usually just give them away or turn a few. Mostly I either turn thin bowls and let them warp, usually natural edge because people like those. Or I rough turn them and put them away. the problem with rough turning for me is I never get back to them. When I moved I packed up about 30. When I unpacked I gave a bunch away because it was obvious I'd rather turn other things than bowls and so they just sit there.

 

[hockenbery]

Large blocks don't dry quickly and rarely dry without cracking.

A roughed out bowl will dry much more quickly than a thick block and be much less likely to crack.

Turn some natural edge bowls 1/4" wall or less thick. They will dry within days.

 

[Bill Boehme]

I'll echo what John and Al said and add that even if you wait years for the block to dry and the possibility of cracks, a more important concern, at least from my limited experience would be the spalting getting out of hand as well as the wood getting too punky. Even if it didn't have mold and you let it "dry" before turning, I think you would discover that the wood will warp to some degree anyway because of internal stresses being relieved. At least, that has been what I frequently encounter with figured maple.

 

[hockenbery]

Or I rough turn them and put them away. the problem with rough turning for me is I never get back to them. When I moved I packed up about 30. .

I'm like you on roughed out bowls. Most of my turning is hollow forms, natural edge bowls, and some spindle stuff from dry wood.
I rough a few bowls every year but seldom turn them.

The 3 sand carved bowls I posted a while back are likely the only twice turned bowls I have finished in 3 years.
And I did one the year before that.

A friend in another club getting ready to move had a couple hundred bowl blanks available that he decided not to move.

Al

 

[John K Jordan]

I agree with what was said so far. I prefer to turn dry. I do have some fairly large spalted blocks that have been drying for 10 years or more. Big chunks take forever to dry and there is no guarantee they will survive intact. The old "rule of thumb" of 1 year per inch plus one year falls apart over a couple of inches. I've cut some blocks apart after many years of air drying and still found elevated moisture with my meter. Most of the wood I'm turning now has been sir drying for a while, some since 2003. (I date the chunks with a marker when I cut them.)

For saving and drying blocks, I always cut out the pith, cut into chunks or spindle squares, slice off thin slices of end grain and bend each one until I get past any hidden end checks, then anchor seal immediately (usually within one minute.) If hidden end checks are not removed they can grow into deep checks and splits.

I also anchor seal the sides if there is figured grain, knots, or distinct sap/heart wood boundaries. I usually cut the blanks square or mostly square. I put them on the shelf with plenty of air circulation. I have been successful in drying blocks this way up to at least 8" square and 12" or more in height.

I can't promise this, but it seems to me that spalting in progress quits at this point, unless put directly on the concrete floor on stacked with other pieces where air can't get all the way around. (If I have to stack, I like to shuffle the stack occasionally) I have had pieces continue spalting if wrapped in plastic. I've also read of people putting big blanks in a freezer to save them but I've only tried it with some smaller pieces, say 4x4".

Another thing is the type of wood. Some, like cedar, walnut, y. poplar, and sassafras are hard to mess up. Others, like persimmon and dogwood will warp and split like crazy regardless of what you do. I process a lot of dogwood and while I do have some 5" thick pieces that have survived, I cut most into 3" or smaller spindle squares to minimize loss. (dogwood is my favorite domestic wood!)

JKJ

 

[Bill Boehme]

.... I can't promise this, but it seems to me that spalting in progress quits at this point, unless put directly on the concrete floor on stacked with other pieces where air can't get all the way around. (If I have to stack, I like to shuffle the stack occasionally) I have had pieces continue spalting if wrapped in plastic......

I don't know about spalting, but mold can get out of hand on maple if Anchorsealed when the wood is still dripping wet.

 

[Zach LaPerriere]

Here in Alaska where I can dry things slower, I often cut a bowl blank on the bandsaw and let that dry semi-slower before putting on the lathe. Days to a couple weeks in the coldest part of the winter. Sometimes in shavings under cover outside...just depends on the piece. I find the wood cuts better when it's dried out a bit, but my experience is limited to just a few local hardwoods. My goal is to turn the piece right before it starts checking.

The challenge with spalted bowls for me is to dry the roughed bowl fast enough to not mold but slow enough to not crack. Drying the rough blank a bit helps some. Part of my answer is to dry blanks cold—supposedly mold won't grow below 41 F, and when the temp is in the fifties mold seems to take longer. Sometimes I give a quick torch to the blank right after rough turning, just enough to dry the surface—but this would cause immediate cracks in some species, know your wood before trying. 10% bleach solution is another good fix when mold is just beginning.

 

[John K Jordan]

fun with maple

I don't know about spalting, but mold can get out of hand on maple if Anchorsealed when the wood is still dripping wet.

I wonder if that depends on the outside temperature and humidity, or even the number and kind of mold spores in the area. I've never had maple to mold after sealing but I mostly (but not always) process wood in cooler weather.

I did have one VERY interesting experience when cutting and sealing maple. While working I watched a number of little beetles, I assume powderpost beetles, fly from the direction of the woods towards me and my pile of maple chunks. I watched them land on the wood and immediately start boring into the end grain!! There were a bunch, maybe two or three landing on the end of each chunk of wood. And they were fast to bore inside. I assume the smell of the wood attracted them. I started smacking them but was overwhelmed so I grabbed some insect spray and blasted the wood. I've seen the holes before, of course, but that was the only time I ever saw a hole get started!!

And to round things out, some years before I actually saw a beetle come OUT of a piece of wood! Imaging the chance of that. A friend had given me a few pieces of 2x2 walnut squares which I had on a shelf about head height near where I was standing at the lathe. I kept hearing an odd little "skritch, skritch" noise and while hunting for where it was coming from I saw a beetle come out of the endgrain of one square! Yikes, but also amazing to see. Needless to say, I moved those pieces out of the shop!

JKJ

 

[Bill Boehme]

Seeing beetles is not unusual for mesquite ... in fact, it is unusual to not seem them. 🙄

I bought a bunch of wet and heavily Anchorsealed ambrosia maple blanks at SWAT last year so that I could turn some bowls for the local Empty Bowls event. It wasn't long ... maybe it's the Texas heat and humidity, but the blanks had a lot of pitch black mold and my culture was thriving from what I could see. I decided to rough them out and just lightly Anchorseal them which stopped the mold problem although the wood wound up with some gray stains because some of the residual graying effects of the mold had penetrated all the way through.

 

[Jamie Straw]

[Snip]...maybe it's the Texas heat and humidity, but the blanks had a lot of pitch black mold and my culture was thriving from what I could see. I decided to rough them out and just lightly Anchorseal them which stopped the mold problem although the wood wound up with some gray stains because some of the residual graying effects of the mold had penetrated all the way through.

Like this? Bowl is punky, but I'll be interested to see if the spot stays black after drying:


Hate that graying thing. I've tossed two dry bowls because they developed Gray Disease and it didn't turn away.

 

[Bill Boehme]

Like this? Bowl is punky, but I'll be interested to see if the spot stays black after drying:
View attachment 9503

Hate that graying thing. I've tossed two dry bowls because they developed Gray Disease and it didn't turn away.

The black was only on the exterior of the blank. However it causes the wood beneath the surface to turn splotchy gray and look dirty.

 

[John K Jordan]

Hate that graying thing. I've tossed two dry bowls because they developed Gray Disease and it didn't turn away.

Don't forget - a good shape with ugly grey stain (I also hate it) can be an excellent opportunity to try some color and texturing experiments. You may end up with a museum piece! David Marks impressed me with some of his dyed and guilded pieces that looked even better in person than in the pictures. My favorite actually had no visible wood on the outside!

JKJ

 

[Jamie Straw]

Don't forget - a good shape with ugly grey stain (I also hate it) can be an excellent opportunity to try some color and texturing experiments. You may end up with a museum piece! David Marks impressed me with some of his dyed and guilded pieces that looked even better in person than in the pictures. My favorite actually had no visible wood on the outside!

JKJ

Truth be told, I think I did work with those bowls a bit, just because I needed practice on basic bowl skills (still do, of course) and it would be no big loss if something bad happened.🙄 My finishing experimentation is pretty basic currently, but I'll be sure an take advantage of any seemingly icky bowls down the road and see what might be done with them.

 

[Bill Boehme]

Don't forget - a good shape with ugly grey stain (I also hate it) can be an excellent opportunity to try some color and texturing experiments. You may end up with a museum piece! David Marks impressed me with some of his dyed and guilded pieces that looked even better in person than in the pictures. My favorite actually had no visible wood on the outside!

JKJ

I'll second that suggestion. I have done that with a couple batches of maple bowls with ugly gray stains that bleach didn't help much. I used some Jacquard Lumiere Interference art paint as well as things like Rub N Buff and dyes to create Donburi style bowls (Japanese rice bowls).

 

[robo hippy]

My main concern would be how wet is the wood. The spaulting process depends on moisture content. It is also part of turning good solid wood into compost. The big leaf maple can turn to mulch really quickly. Add to that that the wood loses a lot of the 'shine' if it sits very long, and the color won't be as good. I would at least rough turn as much of it as possible as quickly as possible, and cut the rest up into blanks to store.

robo hippy

 

[MichaelMouse]

Sara is the place to learn spalting whys and hows. http://woodscience.oregonstate.edu/people/faculty/robinson-sara http://www.northernspalting.com/ Cold and dry stop spalting. The easiest one to control is dry, unless it's winter. Turn the thing water-throwing wet to a reasonable thickness and it will dry much more rapidly. Word of caution - mark UP as the log lies and don't allow yourself to get in a position where you're turning a half wet downside and half dry upside. You can shake even a normally rock solid lathe if you're unlucky.

I ended my brief experience with Anchorseal because I have a high RH basement and putting it on soft maples like A rubrum and A negundo got mildew, which discolored a quarter inch in on the endgrain. By then I was more conscious of the geometry solutions with roughs, so it wasn't necessary to keep the endgrain plastic. I used the rest of my first and only gallon to seal the ends of spindle blanks.

 

[Bill Boehme]

I wish that I had turned my prize box elder half log while it was still sopping wet. I bought it at SWAT last year and for various reasons didn't have the time to work on it. It is huge compared to what grows in this part of the country -- about two feet wide by two feet long. I had it in our air-conditioned garage and heavily Anchorsealed because we have hot dry weather here and if you mention the word "basement" folks look at you kind of funny. It had been looking fine, but yesterday I noticed that it was split wide open on the bark side. I had been planning on a set of large nested bowls, (already have a customer for it), but it looks like this piece will become a couple vases instead.

Moral of the story: I should have rough turned it right away. Besides, turning wet wood is fun when you can get a shower at the same time.

 

[MichaelMouse]

Besides, turning wet wood is fun when you can get a shower at the same time.

If you're getting a shower you're standing on dangerous ground. Get away from the throw zone before it's something besides sap being tossed. I get wet from my left knuckles to my left elbow where I stand, with an additional benefit that I can drop the shavings produced direct into the bag placed at the headstock. http://i35.photobucket.com/albums/d160/GoodOnesGone/P3140057.jpg When digging inside, the shavings hit the wall and fall on my table where I don't have to stoop and scoop.

If you don't cut for round, whittling away the edge first will help control any weight imbalance shaking the lathe. I'm a safety guy, so I do this kind of thing, and I can start center and cut down hill. http://i35.photobucket.com/albums/d160/GoodOnesGone/Trim-for-balance-1.jpg At the very minimum, undercut with the chainsaw if you're going to cut it away anyway.

As to "bowl" gouge roughing, I don't normally use it outside, as people know. I slice with broad sweep gouges. Removes stock rapidly and safely at arm's length. Inside roughing is where I use cylindrical gouges.

 

[Bill Boehme]

Just to clear up any misconceptions about showering, I was just kidding. I do my showering the traditional way. 🙄

The bigger a piece is, the more likely it is to follow the same path as the water if it dismounts but wood that slings water does turn like butter. I'm a firm believer in doing things safely. Taking risks isn't macho ... it's more like not using good judgement.

 

[Raul McCai]

I vote green.
One of the benefits of green turning I rarely see mentioned is the dust. Green wood is Less dusty.
Seems to cut nicer too.