Drying dense/exotic woods

[Isaac Litster]

Would it be a poor decision to kiln/microwave-dry dense or exotic woods? The wood I have in mind is mountain mahogany. Freshly cut, the MC is already low, but it will still take years to reach equilibrium. With my homemade kiln, the drying will take much less time, but I am wondering if there are any major concerns with doing this. What I'm considering is that some woods, such as walnut, are significantly worse in color when kiln dried, and lots of woods are worse in terms of workability after kiln drying. Has anyone with experience with drying exotics or other dense woods noticed worse color or workability as a result of kiln drying? Would the shear hardness render the brittleness of kiln drying negligible?

 

[Wyatt Holm]

I would not microwave or kiln dry dense, sensitive woods. I understand that you want to slow down the drying process rather than speed it up. The last sensitive dense wood I tried was rough turned, coated in anchorseal, then placed In a cardboard box and taped closed for a few months.

 

[Kent Reisdorph]

The only things I have microwaved were bowls. I don't think it would be effective on blanks, logs, etc.

 

[hughie]

Well, my experience is slow and natural. Micowaving works, but every species is different, so what works with this one, wont necessarily work on that one, you need a lot of accumulated knowledge.

 

[Richard Coers]

Any process to speed drying of any species of wood is a high risk. Unless you put the wood under a hard vacuum with some way to warm the wood in the vacuum chamber to around 90 degrees F.

 

[John K Jordan]

I air dry all woods, exotic or not. I think microwaving works better for wood with open pores so the moisture can escape. And on smaller pieces. Many exotics don't have open pores. The Cocobolo I have, for example, has pores filled with what looks like resin.

 

[Dean Center]

Issac, considering where your mountain mahogany lived it's life, it probably got MORE wet when it got to you. It should not take long to reach equilibrium and the rule of thumb of an inch per year doesn't work. I'd recommend patience, and weighing rather than using a moisture meter.

 

[Michael Anderson]

If you go the microwaving route, it might be worth boiling the wood beforehand. I’ve found that can help reduce cracking (no guarantees though, and I have 0 experience with mountain mahogany)

 

[robo hippy]

I would consider rough turning to be the better option. Anything over 2 inches thick never reaches moisture equalization which means the inside is at a higher moisture content than the outside. I would guess that what ever it is that you want to dry, it will even out if you rough turn it. I rough turn ALL box blanks, which I learned from Richard Raffen. The Mountain Mahogany I got was drier than anything I had ever turned. It was growing at 8500 feet outside of Lost Wages, NV..... A friend called it that once and I liked that name for Las Vegas....

robo hippy

 

[John K Jordan]

I would consider rough turning to be the better option. Anything over 2 inches thick never reaches moisture equalization which means the inside is at a higher moisture content than the outside.

I agree with the rough turning, even with very dry wood because of the possible internal stresses. Even equalizing overnight can be enough. Raffan taught this.

But I might change "anything over 2-inches never reaches" EMC to "can take a LONG time" to reach EMC!

One issue is dealers often coat exotic blanks with a thick layer of wax, often by dipping in hot paraffin - this preserves their investment by minimizing checks/cracks (and can make the wood look better!) What I do to speed drying is air dry until the weight changes significantly, then scrape off as much of the wax as I can with a card scraper. This still leaves a thin coat of wax but the final drying is quicker (tracking by weight as always). Occasionally, if I know the woodis very close to dry I'll even heat the wax with a heat gun and wipe it off with rags or paper towels. (For most things I still do the roughing thing, especially with lidded boxes.)

JKJ