Breadboard end extreme movement?

[keith micinski]

I built this table I think two years ago exactly and I just happen to see it for the first time today. I told the client to expect the breadboard ends to experience movement throughout out the year and while she is happy I am a little bit shocked at how much the table shrunk this winter. This seems to be easily double what I would have expected what do you guys think?

[keith micinski]

This is the end I believe this summer but I am not exactly sure. It was at least a year after the table was delivered.

[Jim Matthews]

1/16" per foot over a year - how wide is the table top?

[Mel Fulks]

I would guess that the wood was not kiln dried. Air dried is always going to move more.

[John Downey]

Looks like the high side of what I've seen, but not too shocking. I always figured the Greene and Greene business around the breadboard ends was to provide visual distraction from the extremes of movement.

[keith micinski]

The table is 36" wide and is kiln dried crotch walnut. It's an inch and a half thick. I am going to keep an eye on it over the next few months I might have to trim a little off of the breadboard ends.

[Dick Strauss]

Assuming that you go from 10% (kiln dried) to 4% moisture in the black walnut, you should expect 0.44-0.63" of shrinkage over a 36" wide table using the woodbin calculator (http://www.woodbin.com/calcs/shrinkulator.htm).

[Jamie Buxton]

Assuming that you go from 10% (kiln dried) to 4% moisture in the black walnut, you should expect 0.44-0.63" of shrinkage over a 36" wide table using the woodbin calculator (http://www.woodbin.com/calcs/shrinkulator.htm).

But why would you expect 4% EMC? Hoadley, for instance, shows mid-winter interior EMC in Indiana of 7%.

[keith micinski]

I built it in late winter early spring and was actually worried it was going to go the other way and I was going to have a problem in the summer time.

[Mel Fulks]

Dick, I know the info you referenced was written by an expert, but I think it is too long and yet not completely clear. He says that kiln dried will shrink less and gives a percent range if stored inside. I think Inside OR OUTSIDE UNDER COVER is more accurate. Many of us have had to bring in KD wood stored for long periods outside and start cutting it up immediately , if gluing is needed it might start the next day. Saying "stored inside" implies that the kiln drying will be easily undone. I posted before about soaking KD and AD samples from same board ,and comparing movement . It took a couple of complete soak to dry cycles to undue the superior stability of KD. Some are interested in ,and need to,dry their own wood but for most commercial use the specs call for KD . Observing that spec and buying lumber from a known reliable source prevents most of what OP is concerned about.

[Andrew Hughes]

Seems like a lot of movement to me esp when I see some quarter sawn.What finish is on the table that's allowing the wood to move soo much moisture from the air.Maybe it's just the climate.

[keith micinski]

It's a lacquer finish. I will say I used this wood about a week out of the kiln.

[Stephen Pereira]

This problem is a good reason to bring air dried wood inside and let it "get used to" the environment before using it for projects..esp wide glue ups.

[Brian Tymchak]

Does the table sit near or over a heat vent?

[Dave Cullen]

It might help to humidify the environment. Good for people as well as furniture.

[Richard Coers]

The table is 36" wide and is kiln dried crotch walnut. It's an inch and a half thick. I am going to keep an eye on it over the next few months I might have to trim a little off of the breadboard ends.

Kiln dried doesn't mean as much as an actual moisture reading. Movement looks normal to me. With this incredible cold snap and lots of furnace running time, humidity levels are really dropping!

[Mel Fulks]

Oops, I missed the crotch grain spec. That tangled grain hath spun this thread !

[Mel Fulks]

I disagree that KD is the weaker factor .In the test I did on two pieces of walnut which had been ADJASCENT IN SAME BOARD only one was KD ,but both had been air dried for years . Soaked in water the 13 inch wide KD piece did not expand at all ,the AD piece swelled 3/32 of an inch . Both pieces were then air dried and tested again, less difference. My guess is that a thorough soaking over days can put water back in cells as well as between them, but I'm only interested in practical result.
The pieces used are only 3 inches long so that water could soak in well. I worked for years thinking that percent reading was the whole story . It's not. Kiln used was brand new 20 foot computer controlled.

[keith micinski]

I also was thinking the crotch and heavy figure of the grain maybe led to a little more shrinkage then normal. I will be interested to see come spring where It's at. The good news is if I need to trim a little off to balance the movement out a little I can still do that where as if it was to short I would pretty much be stuck with it.

[Mark Bolton]

I disagree that KD is the weaker factor .In the test I did on two pieces of walnut which had been ADJASCENT IN SAME BOARD only one was KD ,but both had been air dried for years . Soaked in water the 16 inch wide KD piece did not expand at all ,the AD piece swelled 3/32 of an inch . Both pieces were then air dried and tested again, less difference. My guess is that a thorough soaking over days can put water back in cells as well as between them, but I'm only interested in practical result.
The pieces used are only 3 inches long so that water could soak in well. I worked for years thinking that percent reading was the whole story . It's not. Kiln used was brand new 20 foot computer controlled.

Mel,
May take a bit more research, and I know you said you care more about practical results as opposed to whats behind it, but i believe the reason for the KD being more stable even on re-wetting is because the kiln drying process collapses the cell structure and air drying either does less so, or little to none. This is why AD material can act a bit more like a sponge as it re-hydrates as compared to KD material which does not re-hydrate in the same manner.

I cant remember all the details but some quick poking would turn it up I believe.

It seems like something is at play in that 36" of black walnut with a 5% swing hovering aroung the 10%+/- range should only result in about 0.10" of movement.

[Mel Fulks]

Thanks,Mark . I take this opportunity to add that my test pieces had been allowed to acclimate for a few days inside then sanded to exactly the same width before soaking.