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kiln dried versus air dried?

Posted: Thu Sep 24, 2009 11:48 am
by Jim Tesno
Hopefuly soon will actually start on constructyion as opposed to destruction. Ist step will be to replace keelson, then ribs. Have started to look for sources for wood. Have contacted a number of lumber yards and mills in my area and no one has air seasoned/dried wood, they can offer green or kiln dried. I realize issue with green wood is shrinkage and perhaps taking it's own shape as it dries and issue with kiln dried is lack of mositure for bending.

Any reason I can't use kiln dried for keelson?

One lumber yard is somewhat willing to let me loose with a moisture meter. I understand I want 22% + for ribs to bend, correct? How can I tell by sight if it's heartwood?

If I can't find air dried, can I get away with kiln dried if I soak it for a few days (or more) to get the moisture content up?

If I must have air dried, anyone know a source? (I'm in Ohio, against the Indiana border about 1 hour No. of Dayton)

Sorry for all the questions but obviously I need all the help I can get.

Posted: Fri Sep 25, 2009 5:37 am
by LancerBoy
Kiln-dried is fine for straight pieces. I attempted steam bending rib stock that was kiln-dried. It was a futile effort. Even with soaking the wood for about two weeks, about 80% of the ribs broke during bending.

So, try to get fresh cut wood. Straight grain with no run out or knots. You can let it air dry for a while if you feel it's too wet.

Of course use only white oak that is all heart wood. Don't use any sap wood, as sap wood is not decay resistant. Heart wood will be a bit darker.

My employer was buying millions of board feet of all heartwood white oak from a mill in Indiana a few years back. I can't recall the name and I don't have access to those records. So, there must be plenty of good all heart wood white oak in that area.

Andreas

Posted: Sat Sep 26, 2009 7:31 pm
by thegammas
Andreas, would love to know where they are sourcing all that white oak heartwood. Maybe call some old colleagues?

Posted: Sun Sep 27, 2009 6:46 am
by LancerBoy
The last few years several million board feet has come from a mill in West Virginia, called something like Hamer Brothers.

Andreas

Posted: Sun Sep 27, 2009 11:14 pm
by t3
Jim,

I think you'll be fine bending kiln dried oak for your frames. You just need to be
mindful of a couple of things:

1) Choose/cut your stock to minimize grain runout.
2) Get your steamer up to temp. before loading. ( 212 deg)
3) One hour per inch of thickness

I've bent lots of KD wood this way with great success. I imagine for bigger
timbers it may be easier to bend green wood, but for the size of the parts on your Thompson I don't think it matters.

Give it a try, if it doesn't work for you ,THEN look for green wood. It's a lot easier to use what's available than to try to find something that may not be necessary.

Posted: Mon Sep 28, 2009 8:57 am
by JoeCB
I recall discussions in the past where the issue of temperature was identified as paramont to sucessful bending. Moisture in the wood acts mainly as a conductor of heat into the core of the stock, the more moisture the less time it takes to bring the stock up to temp. So, as suggested above ensure that your stock is fully up to 212 F

Joe B

Posted: Fri Oct 02, 2009 3:22 pm
by LancerBoy
J.P. Hamer Lumber Company of Kenova, WV is the source of the all-heartwood white oak lumber for Sentinel Structures, Inc.'s marine laminating operation. There have been recent purchases and some as far back as 1963.

Andreas