Walnut Crotch Slabs

[joekwon80]

I've come upon 3 4 inch thick walnut crotch slabs and as I was getting them surfaced realized that they were moist to the touch. Is there any way for me to find out how wet they are? They were given to me by a lady who had fell the tree 4 years ago and hadn't covered the wood. Each slab is about 4 inches thick.

If it's not dry would kiln drying it be bad? If not does anyone local to durham have a kiln?

--Joe

 

[Touchwood]

OMG Joe...don't even think about kiln drying beautiful slabs like that right now. They were sitting outside in rain and weather for a while, but some drying took place I guess in the Summer

My first thought is to get them stickered inside properly. When they get down to maybe 15% MC you could think about putting them in a Kiln.

Do you have any idea of MC now?

Actually the real pro to talk to about drying walnut is Scott Smith

Don

 

[mkepke]

Easy to check the MC..find someone with a moisture-meter. I have one, but I think you are a bit far from me.

-Mark

 

[scsmith42]

Hi Joe. Pretty slab!

How long has the wood been milled? If more than a couple of years odds are that it's dry inside and just needs to have the surface rainwater dry off.

If milled recently, your best bet is to stack and sticker them in a cool location outdoors and let them air dry for around 2 years. I would avoid keeping them indoors because you don't want them to dry too quickly on the surface (could case harden or otherwise check badly).

You don't want to go into a kiln with these any time soon, as walnut retains more color pigmentation when it is air dried.

 

[NC_Horn]

Make a run to Harbor Freight. I picked up a moisture meter there for $12.99 when I picked up a load of rough sawn Cypress from Ivey. Worked fine for what I needed. You could use mine but the gas to get here and back would pay for the one from HFT.

Duane

 

[joekwon80]

Thanks for the replies folks! I didn't realize kiln drying is that bad. I just cut these up about a week and half ago. They are stacked now and just waiting to be turned into end tables! What moisture content should they be at to safely turn them into furniture? I'm new to this world for fresh wood and have no idea what Stickering is either.

oh some background on the wood. It was sitting on the ground not elevated and not covered either for four years. As far as I know it was dead when they took it down but for how long I have no idea.

 

[scsmith42]

Joe, it's not that kiln drying is "bad"; usually it's a very good idea. With black walnut however, there are a few tricks to use in order to maximize the color.

First off, the drying rate is based upon the thickness and initial moisture content, with thicker and wetter wood requiring a slower rate. 4" thick slabs require an extremely slow drying rate or you will damage the slab.

Wood dries very poorly in log form, and it is customary for certain species (such as walnut) to retain their full moisture content in the heartwood for years.

Typical targeted moisture content for furniture is below 10% and above 6%.

Stickering is the process of placing 3/4" or 1" thick small sticks of dry wood in-between layers of your fresh cut lumber, in order to allow airflow around the sides of the boards/planks.

 

[joekwon80]

Thanks for that lesson scott! So I guess I'm just gonna have to wait on these if they turn out to be too wet for working with. I didn't even realize they were wet until my buddy and I started putting it through the wide belt sander.

So outside is better drying condition than in my garage? Or is the garage close enough to outdoor conditions?

It's currently sitting on my outfeed table but I have considered making a hotbox for them to sit in outside. Or would that be too quick too?

 

[eyekode]

Wow, there are not a lot of places that can properly dry slabs like those. My place comes to mind . Jk, that slab is lovely!
Salem

 

[Touchwood]

Joe, it's not that kiln drying is "bad"; usually it's a very good idea. With black walnut however, there are a few tricks to use in order to maximize the color.

First off, the drying rate is based upon the thickness and initial moisture content, with thicker and wetter wood requiring a slower rate. 4" thick slabs require an extremely slow drying rate or you will damage the slab.

Wood dries very poorly in log form, and it is customary for certain species (such as walnut) to retain their full moisture content in the heartwood for years.

Typical targeted moisture content for furniture is below 10% and above 6%.

Stickering is the process of placing 3/4" or 1" thick small sticks of dry wood in-between layers of your fresh cut lumber, in order to allow airflow around the sides of the boards/planks.

Scott

I agree 100%. When Joe said they felt "wet" after surfacing my first thought was.."don't even think about putting them in a kiln right now"

I believe those big 8/4" walnut natural edge planks you sold me last year were several years drying both outside and inside. I wasn't sure if they had ever been in a kiln, but after a year in my shop they're right down to 8-9 %.

In fact I just used them to make some more natural edge benches

Joe, I don't mean to criticize, but I have two different kinds of HF moisture meters and they are not even close to being accurate..might work on wet 2X4s, but not even sure of that.

IMHO it's pretty hard to find a usable meter for under $100. I now have a Merlin RF unit and it compares pretty well with Scott's "gold standard", a 4 point probe meter by Delmhorst, depending on the thickness of the wood.

I think Scott's goes for about $500 and mine was half of that. If you're not going to be buying a lot of wood with "unknown drying history" you probably don't need to go this kind of expense. ...but I would not rely on the HF meter readings.

If you're buying kiln dried wood from folks like Scott, or Anchor Hardwoods, or the Hardwood Store you don't need a meter. If you're going to use wood like the walnut pieces you just got, you probably do.

I would be glad to measure some for you if the occasion occurs, and I'm sure Scott would too.

Don

 

[joekwon80]

That would be great if you could check the moisture on one of the pieces Don. I'm in Durham, but can drop by raleigh with the slab.

Would it be bad to just make a table out of the piece and use it and let it dry in my house?

Does wood move that much?

 

[scsmith42]

Thanks for that lesson scott! So I guess I'm just gonna have to wait on these if they turn out to be too wet for working with. I didn't even realize they were wet until my buddy and I started putting it through the wide belt sander.

So outside is better drying condition than in my garage? Or is the garage close enough to outdoor conditions?

It's currently sitting on my outfeed table but I have considered making a hotbox for them to sit in outside. Or would that be too quick too?

Joe, the key to successfully drying lumber is to do so in conditions that dry neither too quickly nor too slowly. Given a choice between the two, it is much safer to dry "too slowly" than too quickly.

The targeted daily MC% reduction for 4" black walnut is around 1/2% per day, and you're looking at a 79% MC reduction, as green walnut typically has a MC% of 85%. Thus, your slabs would need to be in a kiln for about 4 months in order to not dry too quickly. The kiln would be set so that the RH% was very high - in the 85% range for the first several weeks in order to not dry them too quickly.

You need to get them out of a warm, dry shop sooner rather than later, or else you will risk drying the surface too quickly and damage them. Since it is very cool outside right now, they will dry slowly out of doors and by next summer the MC% will be low enough so that the warm summer weather won't damage them.

DO NOT PUT THEM IN A "HOTBOX" unless you want some nice firewood.... You need to think in terms of SLOW DRYING - not fast drying.

 

[Touchwood]

That would be great if you could check the moisture on one of the pieces Don. I'm in Durham, but can drop by raleigh with the slab.

Would it be bad to just make a table out of the piece and use it and let it dry in my house?

Does wood move that much?

Joe ,

If it's still wet, you betcha. As Scott said drying it with stickers to let air circulate on all sides prevents the piece from not only moving, it will warp or twist if you just leave it flat on a surface so only one side sees fresh air.

Even when wood is kiln dried to 8% it still moves with seasonal humidity variations. For example a one ft. wide piece of cherry can change in width (across the grain, not lengthwise) as much as 3/16" with humidity going from 20% to 80%. If that piece isn't allowed to move in your say, cabinet design, the cabinet will self-destruct in a few seasons.

I'm close to the intersection of I-540 and Leesville Rd.

Don

 

[CrealBilly]

Humm... not much curl in that peice considering it's crotch walnut, perhaps on the other side or in the other three slabs? In any event, send them to me anyways - I'll take care of them for you (insert evil grin here)

 

[Jeff]

Joe,

Nice "discovery" in finding that walnut crotch log. Also, a good discussion from some of the experts here. :icon_cheers

Lignomat offers a selection of moisture meters for casual woodworkers that won't break the bank. This mini-Ligno E/D model is about $120.

http://www.lignomatusa.com/MoistureMeter/moisture_pin_meters_mini.ED.htm

Here's a bit about stickering and air drying freshly cut wood. Air circulation and slow drying is a key factor in preventing the slabs from checking, warping, cupping, etc.

http://www.youtube.com/watch?v=5sN4W_xGi7s

http://www.woodweb.com/knowledge_base/Drying_a_Walnut_Slab.html

 

[joekwon80]

Started working on the other two slabs today. Here's a photo of one of them mid planing.

Are the splits in the wood going to be a problem as it dries? Should I butterfly it now?

 

[Jeff]

I'm going to be politically incorrect and blunt, but so be it. What you're doing is completely contrary to all of the excellent advice that you received from expert members after your initial thread post.

I don't understand what is the hurry to get something done with these slabs? :eusa_pray

 

[joekwon80]

What do you mean Jeff?

I'm following exactly what everyone says. I'm just getting the things flat before I stack them up? Only one of them was flat as I had cut them with a chain saw and they were all kinds of bumpy. I figured getting them flat was part of stacking them? Am I wrong here?

The butterfly question was in regards to getting the thing stable. I don't know a thing about drying wood and didn't know if the cracks would get worse as it dried.

--Joe

 

[scsmith42]

What do you mean Jeff?

I'm following exactly what everyone says. I'm just getting the things flat before I stack them up? Only one of them was flat as I had cut them with a chain saw and they were all kinds of bumpy. I figured getting them flat was part of stacking them? Am I wrong here?

The butterfly question was in regards to getting the thing stable. I don't know a thing about drying wood and didn't know if the cracks would get worse as it dried.

--Joe

Joe, it's definitely ok to flatten them before drying (and this will help them to dry faster); just know that you'll need to do it again after they are dry (due to wood movement during the drying process). If you install a butterfly now, it might become loose as the slabs dry and shrink. Better to take some strapping and nail it across the ends of the slabs to prevent the checks from splitting further.

 

[CrealBilly]

Joe, it's definitely ok to flatten them before drying (and this will help them to dry faster); just know that you'll need to do it again after they are dry (due to wood movement during the drying process). If you install a butterfly now, it might become loose as the slabs dry and shrink. Better to take some strapping and nail it across the ends of the slabs to prevent the checks from splitting further.

OR... He could just send them to me and I'll take care of them