Air dried or kiln dried query?...

identical properties

Re: identical properties - KD vs. AD beech

John Aniano in central NJ

Hi Bill,

Thanks, I sort of thought so.

I did take a closer look at the pieces and noticed the growth rings of KD beech had a bit wider spacing than the AD. How much would this influence the properties for a chisel handle?

John

Re: Air dried or kiln dried query?...

Warren in Lancaster, PA

I would expect the kiln dried stuff to be a little more brittle. This makes a difference if you are making a tapered chisel handle without a ferrule, as was done historically.

You don't need too much extra thickness because when you correct for straightness, either because the tang is a little crooked or your hole is little crooked, that is done in the tapered portion. So the wiggle room is sort of built in with a tapered design.

For old chisels, I usually add length to the chisel handle to make the total near the optimum length. A lot of chisels have lost an inch or two over the years.

Re: Air dried or kiln dried query?...

Steve D, in CT

Starting with one of each would probably show you any differences in workability. I milled a couple of trees in my yard and have been dipping into that wood on small projects and test cutting. The air dried material has a "smoothness" when cutting with edge tools. Not the surface but the feel of the cut. I don't compare with KD because I don't have it but that could be one of the factors that people describe.

That reminds me that I have to go through my neighbor's firewood for some white oak...

Re: Air dried or kiln dried query?...

John Aniano in central NJ

Warren,

Thanks for the recommendation. Yes, these will be tapered octagons without a ferrule.

What would your optimum overall length be for an early-mid 19th century 1" wide tanged firmer chisel? The blade length now is just under 6". I was going to aim for around 11" or 12" overall.

John

Re: Air dried or kiln dried query?...

Warren in Lancaster, PA

Yes, I like about 11 inches. I have some chisels that that are really worn, including some I have used up 2 inches or more myself. In your case I would aim for a little over five inches for the handle; I like to have my whole hand on the handle and have enough left over so the mallet doesn't hit my hand.

Put a little water in the hole for a while before trying to seat the tang.

Re: Air dried or kiln dried query?...

Bill Tindall, E.Tn.

Properly done there is no reason to suspect KD vs air dry lumber will have different mechanical properties. And the properly done applies to air drying too. Lumber is at its greatest risk of changing properties as the water from the wood cells diffuses away and the lumber begins to shrink. This step can happen too fast whether the lumber is passively dried or dried under controlled conditions. If air drying occurs where the summers can be hot, there is more risk winding up with lumber with undesirable properties than in a well managed kiln.

When a company has $100K of lumber in a kiln it is a good bet the company gives the drying process adequate attention. When we bought from smaller operations we did occasionally get lumber that was dried too fast.

Re: Air dried or kiln dried query?...

John Jardin

Bill,

Thank you for your experience on the subject and the clear explanation that you stated.

The two goals of drying

Bill Tindall, E.Tn.

1. Get dry

2. Only experience small gradients of moisture content across thickness and width during drying.

Water moves quicker in hot wood than cold wood. Evaporation rate from wood dependent on humidity.

In ideal air drying the wood is not hot, water moves slowly from the interior to surface and only a small moisture gradient is established. In ideal kiln drying the wood is hot, moisture moves quickly to the surface but the evaporation rate is kept small by high humidity in kiln. Again the result is a modest moisture gradient in the wood.

In either situation too rapid drying at the surface will lead to a high moisture gradient in the wood which leads to stress and tension, unstability and cracks due to differential shrinkage.

The advantage of kiln drying is that it is quicker, something of less importance to the hobby woodworker. And, in the kiln the moisture content can be brought lower than what can normally be achieved by air drying, then brought back up to working moisture content by steaming. Steaming relaxes stress and tension. Also, wood "overdried" does not regain moisture content as much upon sitting around waiting to be used. Hence, at least for the first few years KD wood moves less with changes in humidity. I expect air dried wood eventually becomes as stable but I have seen no data to confirm.

Bottom line, properly done, either KD or air drying works fine for furniture. Personally, I used both.