Lumber exchange idea.

[Mike Johnson]

Is there a reason you would not use a microwave to sterilize the wood?

 

[Mark Hepburn]

Is there a reason you would not use a microwave to sterilize the wood?

Mike, unlike a large commercial microwave, a home microwave may not heat the wood evenly throughout, and gently enough also. It will excite the water molecules and blow out cell walls at higher settings.

I don't know if this will damage the workability or final appearance of the stock though.

At lower settings I imagine it is just pulsing the magnetron, so That may be preferable.

I'm thinking about trying both. But since my smoker just sits unused, is insulated and runs at low temps I think it may produce the best outcome.

 

[Leo Van Der Loo]

Th

Leo,

USDA / APHIS Link also refers to that standard. 56C is not a difficult temp to reach. 133F.

In the HACCP world that's just below minimum acceptable food holding temps, so I was surprised at such a low temperature being the norm.

If that's the standard then it's a simple matter to set the oven to minimum temp and cook the wood for a couple hours. a small pilot hole and probe thermometer to check the temp.

More info on heating temperatures:

http://ucanr.edu/sites/WoodyBiomass/newsletters/FPL_Wood_Handbook33299.pdf

Thanks for the link Mark, yes I would have thought that the temp. needed would be the recognized 60 deg. Celsius, the use of steam seems to be the better way, especially for turning blanks, as dry heat (that also needs to be done longer) would mean severe splitting and checking I’d expect.

 

[John Torchick]

Mark, I can see it now- walnut and ribs. Just don't baste the walnut or put the ribs on the lathe.

 

[Mike Johnson]

Mike, unlike a large commercial microwave, a home microwave may not heat the wood evenly throughout, and gently enough also. It will excite the water molecules and blow out cell walls at higher settings.

I don't know if this will damage the workability or final appearance of the stock though.

At lower settings I imagine it is just pulsing the magnetron, so That may be preferable.

I'm thinking about trying both. But since my smoker just sits unused, is insulated and runs at low temps I think it may produce the best outcome.

Mark,

Rupturing the cell wall is the main reason for the microwave being able to "sterilize" the wood.
Any living organism exposed to the microwaves will quickly heat up internally and rupture the
cell walls of the critters big and small. I have used a microwave on multiple wood blanks to speed
up the drying process, the heating process helps rupture cell membranes of the wood which allows
the moisture to migrate more easily and quicker from the blank. The wood blanks that I have dried
in the microwave turned and sanded like any other wood blanks that I have used.

 

[Mark Hepburn]

Mark,

Rupturing the cell wall is the main reason for the microwave being able to "sterilize" the wood.
Any living organism exposed to the microwaves will quickly heat up internally and rupture the
cell walls of the critters big and small. I have used a microwave on multiple wood blanks to speed
up the drying process, the heating process helps rupture cell membranes of the wood which allows
the moisture to migrate more easily and quicker from the blank. The wood blanks that I have dried
in the microwave turned and sanded like any other wood blanks that I have used.

That's good to know Mike. I was going to try some to see how it responded. I've been spalting some hackberry and think I'll zap some to dry it and see. Thanks!

 

[Owen Lowe]

Mike, unlike a large commercial microwave, a home microwave may (ed: not have the power to kill).

You all remember those ginormous irradiated ants and tarantulas from back in the ‘50s, right?
It was a real hassle to get rid of them, so, whilst ensuring traded wood is pest proofed, let’s not unleash a new hoard of monsters on the world!





Just look at my avatar if my words of warning aren’t enough to convince you!

 

[Mark Hepburn]

 

[Mike Johnson]

I should post my I have a dream speech.
Has to do with wood being free and not being discriminated against because of where they grew up.

 

[Bill Boehme]

Has to do with wood being free .....

You really are dreaming aren't you.

 

[Mike Johnson]

After years of research I have come to the conclusion that wood really does grow on trees.
That Johnny Appleseed dude had the right idea.
Fruit orchards are very good sources for wood if you are looking for local sources.
I just ordered some more olive wood from an orchard, really nice wood for turning.

 

[Zach LaPerriere]

This is a great discussion, and one that I was just unaware of, living up here in Alaska where we only have a few introduced forest pests.

A question: What about air-dried lumber? I have imported all sorts of air dried wood for flat woodwork from reputable lumber yards, with species from all over the world. Most of this has been for boats, but several species have also gone into cabinets, offices, and homes. I've never heard any restrictions on moving lumber across state borders.

 

[Bill Boehme]

There isn't a pest/disease problem with many species of wood used in woodworking, but I suppose that you could ask the lumber dealer about this. The guy in sales may not know anything about this so the question would have to go to somebody in a knowledgeable position (who might be the guy in sales in a small business).

 

[hockenbery]

I've never heard any restrictions on moving lumber across state borders.

Each state has its own regulations regarding plant materials than leave or enter the state.
Some states regulate the transport of certain plant materials within the state usually by county.

The AAW sends out the states regulation to our demonstrators each year if the state in which it is held has restrictions on wood. In some cases a state requires an agriculture inspection of wood from the state it is leaving other states do 't require anything.
Commercial lumber is usually regulated the agriculture departments.
States like Florida and California have a lot of interest in protecting their ag industries.

Here is the Florida regulation on oak.
OAK WILT
Pest States Regulated Materials Regulated
Oak wilt disease AR, IL, IN, IA, KS, KY, MD, MI, MN, MO, NE, NY, NC, OH, OK, PA, SC, TN, TX, VA, WV, WI, and any other state, where oak wilt is determined to be established Rooted trees and seedling plants of oak (Quercus spp.), chestnut (Castanea spp.), chinequapin (Castanopsis spp.) and tanbark oak (Lithocarpus densiflora), and any parts of such plants for propagation, except seed
RESTRICTIONS: The movement of oak wilt disease or host plants into the state from an infested or regulated area is prohibited except by master permit issued by the Division Director. The movement of firewood with bark and unpeeled lumber into the state from an infested or regulated area is prohibited except by a certificate issued by an authorized representative of the state of origin. The certificate shall state that these regulated articles have been treated in a manner approved by the Department to minimize risk of inadvertent introduction of oak wilt disease.

 

[Leo Van Der Loo]

Here’s some on Black Walnut, but as was said most all states do have restrictions on certain trees or wood and plants, the agricultural dep has info I would think

http://nfs.unl.edu/documents/foresthealth/walnut wood quarantine & 1000 cankers.pdf

Ash wood restrictions

http://www.emeraldashborer.info/moving-firewood.php

And here’s one that will destroy just about any hardwood species, in a similar manner as the Emerald Ash borer.

 

[Zach LaPerriere]

To carry this a little further...Can I assume that there are no restrictions on sending dry bowls to various states?

 

[hockenbery]

To carry this a little further...Can I assume that there are no restrictions on sending dry bowls to various states?

Sure! I have never heard of restrictions on finished wood products.
Processed wood in most cases is ok. Lumber is usually ok.

 

[Bill Boehme]

To carry this a little further...Can I assume that there are no restrictions on sending dry bowls to various states?

I turned a mesquite vase a couple years ago and spent a lot of time using a dental pick and other instruments killing the mesquite larvae that didn't get juiced during the turning process. I filled all the borer holes on the exterior with Inlace resin and applied many layers of lacquer both inside and out. I was convinced that I had taken care of all the buggers, but after it had spent a month in an exhibit and it was back home I heard the unmistakable clicking sound of the now mature mesquite beetle. After killing a few more, I put some moth balls in the vase and put a lid on it for a few weeks. I don't know if moth balls have any effect or if I manage to get all of them with the dental pick, but I do know that they are hardy. As far as I know, these beetles are specific to mesquite trees, but you never know for certain if they wouldn't take a fancy to another species of wood. These critters have a good working relationship with mesquite trees and both seem to thrive together.

 

[Zach LaPerriere]

That is a crazy story, Bill! What a hardy critter.

Thanks Al and Bill for your responses...I'd never heard of any restrictions.

 

[Mike Johnson]

I had a large piece of green wood on the lathe last year and discovered a colony
of large black ants while turning the blank. One small hole in the wood blank was
the entry point into the nest.

 

[Bob Bachynsky]

Bill I wonder if you could zap the bowl in the microwave and kill them off...

 

[Mark Hepburn]

I'm definitely anti-ant

 

[Bill Boehme]

Bill I wonder if you could zap the bowl in the microwave and kill them off...

This tall vase was far too large for a microwave oven, but I would have other concerns such as how the Inlace and lacquer finish might be affected as well as what it might do to the wood. Also, the skin depth at microwave frequencies might not be great enough to have any effect on the borers before the wood catches fire. And the overarching reason for not doing it is that Mrs. B would not approve of this unauthorized use of HER microwave in HER kitchen.

 

[Mark Hepburn]

And that trumps all other possibilities

 

[Emiliano Achaval]

I dont think a month does not go by without a visitor stopping by my shop. I have met a lot of great people, made some life long friendships. Most want to take some of my Maui Gold back to the mainland, Maui Koa... Nobody gets thru airport agricultural inspectors, they are ok with green Koa, only requirement is no bark... Several traveling turners bought a $5 carry on at Savers, and filled it with Koa... Only other option is flat rate box.
The first few dozen, I helped out... Now, if you want a large crotch cut into perfect squares for the flat rate boxes, I have to charge for my time...

 

[odie]

I've heard that Europe has some pretty stiff restrictions on wooden products. Also, I read about someone who shipped a wooden finished item to Australia that got hung up in customs....even though the wood was exported from Australia to begin with.