Relaxing walnut

[Jim Jones]

I need to know how long to let some rough sawn walnut relax after cutting them before jointing and planing.

I am building some cabinet doors for a bathroom vanity out of walnut. I let the rough sawn lumber acclimate inside the house for 2 or 3 weeks. They have some warping, bowing, etc. indicating stress.

I cross cut them to 44" sections (enough for 1 stile and 1 rail per section) and let them rest a day. (Is that enough?)

Then I ripped the lumber down to get about 2 5/8" widths.

How long should I let them rest this time before cutting down to rough size (27" and 17").

And should I let them rest again before I start the milling process?

Thanks.

[Chris Padilla]

The best way to determine all this is to take MC (moisture content) readings. I'm banking you don't have such a meter (I'd say most folks do not).

If the wood has dried to the typical 6-8% normally recommended and you have the wood in a relatively stable enviornment (which it appears you do), then I wouldn't worry too much.

Sometime it can depend on the size of the plank you started with. If you have a 16/4 piece you have resawn or ripped or what-have-you, you may wish to wait longer as revealing the inner wood might cause it to move around. If you started with 8/4 or less, I'd just go for it unless you see obvious signs of movement and in that case, you may want to let the wood move and reach equilibrium for a day or two.

Safest bet is to always rough cut a tad more than you need and hope for the best. Remember, wood is a natural product and it can do strange things for no apparent reason. It can just as easily stay perfectly flat as well....

[Jim Jones]

Thanks Chris.

Didn't have any problems with it.

[Lee Schierer]

As already indicated a moisture meter is the best way. Lacking that, you need to consider where the wood was before it came into your shop and how long it was there. If it was stacked and stickered indoors before you got it then 2-3 weeks in your shop should be sufficient if the lumber was already dried properly. However, if the wood was stacked and stickered out doors then I would recommend 6-8 weeks in your shop before working it. If it wasn't dry then all bets are off and you need to dry it properly.

Wood takes about year per inch to dry on its own, so thick wood isn't going to adapt to being in your shop in a short time either.

[Phil Thien]

There are two issues to concern yourself with.

The first is moisture content.

The other is the internal stresses that are often released when the wood is machined.

Wood that "moves" right after machining is moving because of those released stresses.

Wood that stays straight immediately after machining, but subsequently moves over the next few hours, is moving because of a moisture imbalance.

Sometimes wood will move right after machining, and then move some more over the next few hours. Those pieces have internal stresses AND moisture imbalances.

If you are concerned, my suggestion is to cut oversized (leaving plenty of waste) and then wait a day. Then go back and machine to final size.

[Bill Arnold]

Regardless of what my moisture meter says, I mill in stages. Starting with rough sawn material, I face joint and plane only after cross-cutting a little more than I need. If I need 3/4" final thickness, I'll plane only to 7/8", then let the wood rest overnight. Next, I make the rips I need but still keep them oversize and, again, let them relax overnight. Then, I start working toward my target thickness on my jointer and planer. I always make my next-to-final length and width cuts 1/8" to 1/4" oversize, depending on the final dimension.

This process works for me, but I'm also not running a production shop. I've seen kiln-dried lumber bow like crazy when the stresses are relieved in the ripping process. Taking the steps I do has saved some wood from becoming scrap.

[Jack Camillo]

Regardless of what my moisture meter says, I mill in stages. Starting with rough sawn material, I face joint and plane only after cross-cutting a little more than I need. If I need 3/4" final thickness, I'll plane only to 7/8", then let the wood rest overnight. Next, I make the rips I need but still keep them oversize and, again, let them relax overnight. Then, I start working toward my target thickness on my jointer and planer. I always make my next-to-final length and width cuts 1/8" to 1/4" oversize, depending on the final dimension.

This process works for me, but I'm also not running a production shop. I've seen kiln-dried lumber bow like crazy when the stresses are relieved in the ripping process. Taking the steps I do has saved some wood from becoming scrap.

Great advice. I, too, have had kiln-dried lumber bow to worthlessness immediately, in the walk from the bandsaw to the bench

[Jon Grider]

Try dimming the lights, some soft music, and a nice cup of herbal tea...that walnut will relax like nobodies business. Oh well...it's Friday after a very stressful week, forgive my lame attempt at humour.

[lou sansone]

for wider boards you have to take care to keep them from warping if you have just moved them in from the outside. I make sure that both sides of the lumber can get to the dry shop air by sticking or using drying racks. if you just pile them on top of each other, the top board will usually cup.

as others have said, a moisture meeter is important. up here in ct, lumber that I store in my unheated building is at 12-14%, once I bring it in my shop, it will go down to 6 to 8 % over the next few weeks. but for narrow stock, you really should not be getting real noticeable movement. door stock should be as straight grained as you have in the lot of wood. if not it will warp as you are seeing and from my experience will give you trouble for ever.

Lou