Moving water out with denatured alcohol

[burdman_22]

I've seen folks in the past talking about soaking cookies in denatured alcohol to help dry cookies without them cracking as much. If I soaked a 1 inch board in denatured alcohol for a week or so, would it absorb alcohol and displace enough water so that it speeds up the drying process? I've saved a couple offcuts from my most recent milling and was looking for a quicker way of drying them.

Also, anyone had any luck drying smaller chunks of wood in a microwave? I'm curious about trying this as well, but dont want to ruin my board or my microwave.

[GeneWengert-WoodDoc]

Microwave drying must be done carefully, as you can heat the wood enough to get it to burn.  So, probably the lowest setting possible, maybe even defrost, might work.  But if you dry a piece in an hour, it probably will not have good quality...microwave ovens have too much power and dry too fast.  On the other hand, very small pieces can be dried successfully.

[GeneWengert-WoodDoc]

Using alcohol for drying is well known technology.  When soaking, the alcohol goes into the wood and displaces the water.  The water comes out of the wood and the alcohol goes in without any size change.  However, as the water comes out, the alcohol solution becomes a mixture of more and more water with less and less alcohol as you dry more.  You may have to add more alcohol and remove the water.  Be aware of fire hazard.  

Once the alcohol is in the wood, which means the wood must be somewhat porous so the alcohol can get in and the water can get out, the alcohol can be evaporated quickly and yet the wood will not shrink as the alcohol evaporates. 

 Are alcohol fumes and air pollutant?  Visit a bourbon or whiskey plant and the surround trees will tell you.  Be aware of fire and possible health hazards to you.

Also, at a commercial level, you would certain try to recapture the expensive alcohol.

Now, this dry wood will gain moisture when exposed to higher humidity and swell.  It will shrink when the moisture leaves.  So, the stability in drying is not permanent.  However, the moisture changes and size changes in most cases would be pretty small.

In my opinion, the risks of fire and health issues mean that it is not a process to mess around with.

[Ianab]

Also, anyone had any luck drying smaller chunks of wood in a microwave? I'm curious about trying this as well, but dont want to ruin my board or my microwave.

A microwave can be used to dry wood, that's how the fancy RF (Radio Frequency) kilns work. But like Gene says, you have to use very low power, or short bursts and then let the wood rest. You want the wood steaming hot, not smouldering. I'd experiment with some junk off-cuts first. 

It wont break your microwave, but it will probably smell like hot wood for the next month. Best to use an old one out in the shed, not the wife's good one in the kitchen. 

[doc henderson]

I have increased the yield of cookies without the sap split using denatured alcohol.  made a bunch for a wedding. 7/8th thick, and about 10 to 12 inches round.  the cheapest brand was sunnyside via Menards.  It was used on walnut, so reuse started to stain the sap wood, kinda like steaming for color.  I soaked a few hours, to overnight, then dried them in a closed box to slow things down.  being in the south, you could run the used stuff through a still and re-de-still off the alcohol. 8)
you want a container to fit the size of the wood so you do not use a large volume to submerge the piece.  I used 30 gallon metal barrels with lids.

[doc henderson]

 

 

 

 

 

 

the old way we made coasters.  the girl who got married, now with two kids.  you can see the cookies in various stages.  we used Danish oil for a satin finish.  did not like the look of the poly.  sanded in a 24 inch grizzly drum sander so the bark would stay on.  I have many of the cookies left over in my shop.  note the drying cookies on the steps.

[Larry]

As a woodturner, I dry green turned bowls all the time in the microwave.  I use the automatic defrost cycle.  I can cut down a tree, turn a bowl, dry it, and apply a finish in a few hours.  I'll have to run it through the defrost cycle maybe 6 times letting it cool between each cycle.  Never have any problem with cherry and maple.  Oak can be problematic. 

I've also tried alcohol drying on a limited basis.  It seems to reduce the initial MC but doesn't dry completely.

Drying wood in a sand filled pot heated by a hot plate to no more than 180 degrees is another method.  I dry tenons for chair making using this method.

Small scale vacuum drying can also work.  If you want to try it get the book Vacuum Kiln Drying for Woodworkers by Joshua Salesin.

[doc henderson]

the alcohol method is billed to reduce splitting in rounds as well as the slow it down inside a box method.  those cookies are 4 years old and never did split.  larger cookies would prob. still split some.

[burdman_22]

Thanks for the info folks. Just looking for a way to dry some smaller project pieces quickly to give to some friends. I might try a piece this weekend (though it will have to be in the kitchen microwave)

[doc henderson]

I have used the kitchen microwave to dry for Mc calculation.  when it turns to a gray smoke that smells like BBQ, you are done in the house.  you can also use a convection oven over 24 hours.