Yet another alcohol question - dilution

Re: Yet another alcohol question - dilution

JL

>Yes, there is a chemist in the house. Specific gravity is an excellent way of testing for the water content in alcohol. Denatured alcohol has a density of about 0.81 grams/milliliter. A 50/50 mixture of alcohol and water has a density of about 0.93 grams/milliliter. All you need is an accurate scale and either a volumetric flask or a pycnometer (very fancy and expensive). If interested, I can generate a chart.

Colorants and other extractives probably aren't much of an issue in the alcohol content. A little color goes a very long way. You figure that most of your extractants will be on the order of milligrams/milliliter. Let's see that's 1-2 mg in maybe 850 mg or arround 0.2%.

My $0.02.

Re: Yet another alcohol question - dilution

Ron in Drums PA

>Dilution is not really a problem since you always need to replace what is lost during use.

Re: Yet another alcohol question - dilution

Mk

>Another question. When the alcohol becomes darkened, would it best NOT to use that on a lighter colored wood? Will it color it through the whole piece?

Re: Yet another alcohol question - dilution

Barbara Gill, Remlik VA

>When I have boiled a light wood after a dark wood, the discoloration is judt on the surface; it turns right off. I would assume the alcohol is the same.

Of course if you don't plan to turn it again....

Re: Yet another alcohol question - dilution

Roger Dunn

>My alcohol soaking tub has been in use since November. Even with evaporation and adding more DNA, it is the color of Guiness Stout. After soaking and drying whatever darkening of the fibers is either turned away and or sanded away. As an example here is a horsechestnut bowl that was roughed, soaked in the dark alcohol. But after wrapping and drying it sanded up very pale and when finished only darkened with the brew of Tung oil and McCloskeys.

Re: Yet another alcohol question - dilution

Ron in Drums PA

>My alcohol is pretty dark. I dried some Holly and the stain was only on the surface.

Re: Yet another alcohol question - dilution

DWFII

>This raises a question...

From the answers given here and previously...if the stain is only on the surface what does that say about overall alcohol penetration?

My first thought is that if the colour dissolved in the alcohol doesn't penetrat any further than a few millimeters, then perhaps the alcohol is not penetration any further than a few millimeters.

I'd be a lot more confidant that there was thorough alcohol penetration if the stain were all the way through.

Can someone address this?

DW

In the High Desert of Central Oregon

Response to DF

Roger Dunn

>Color doesn't matter. The alcohol displaces the water whatever color the wood ends up. It is the weight of the water displaced that makes the difference, and once the water is in equilibrium with the surrounding atmosphere, no cracks, no warps and a bowl is ready to finish. In 1963 Bill Cosby's classic album "Why is there air?" was a huge success. The answer was not metaphysical. Air is for blowing up volleyballs. Trust the process.

Re: Yet another alcohol question - dilution - long

JL

>You said:

"My first thought is that if the colour dissolved in the alcohol doesn't penetrate any further than a few millimeters, then perhaps the alcohol is not penetration any further than a few millimeters.

I'd be a lot more confidant that there was thorough alcohol penetration if the stain were all the way through.

Can someone address this?"

Let's talk about sizes of molecules. The relative size of the ethyl alcohol molecule and the water molecule are both pretty small. How large are the "color body" molecules or the extractants? On a relative size, pretty big in comparison. The molecular weight is a "fair" indication of size. The molecular weight of water is 18 and the molecular weight of ethyl alcohol is 46. Many of the "color bodies" have molecular weights well over 100. The chemistry is also usually quite different. The "color bodies" aren't going to diffuse into the wood as far as the alcohol - they are too large and have a different chemistry. The "color bodies" are going to diffuse in to the limits of the existing porosity in the wood surface. Over time, yes, they might diffuse all the way in. But how long and under what conditions?

How far does a stain typically penetrate into a piece of wood? Not that far. How far does a dye penetrate? Not that far. The sizes of the molecules aren't conducive to a large depth of penetration.

Re: Yet another alcohol question - dilution - long

DWFII

>JL,

That makes sense to me and alleviates some of my concerns. I have a maple bowl that I soaked in alcohol and have had drying...slowly...slowly...for over a week now (My first attempt, with black locust was a fiasco) and so far so good.

So I'm one for two (fingers crossed).

thanks for taking the time...

DW

In the High Desert of Central Oregon

Re: Yet another alcohol question - dilution

Shawn - in ID

>This was the point I raised way back during some of the original long threads here on this topic. I haven't measured penetration into wood but my experience with other applications suggests that you are really quite right and penetration of the ethanol, while incomparably further and faster then any dye, is still not complete in the short time that everyone is soaking. All you are really doing is diluting the water with a solution that will evaporate and move back out of the wood quickly; in addition there is likely some cell wall structural integrity that is lost, without effect on the overall strength of the wood. This will facilitate water and ethanol movement without imposing great cell wall stress (i.e., cracking). I'd bet everyone would have more success with longer soaks (in combination with reduced air circulation during the first 48 hours out of the solution - anyone put a soaked bowl in the freezer for a week or two?). Noone addressed your agitation question - no doubt this would be of some benefit but only very minor - the real issue is what is going on inside the wood and only severe agitation would change that.

Re: Yet another alcohol question - dilution

DWFII

>Shawn,

I don't reallyhave the expertise to say one way or the other. I would think that staining from the wood in solution in the alochol might be different from stains and dyes. But I will say this...

I soak my bowls at least 24 hours and more like 48. I have coated the outside end grain with AnchorSeal. I wrapped the latest bowl in newsprint every night and leave it sit, upside down on a narrow pedestal, in a warm shop, in the open, completely uncovered, all day long. It has been out of the alcohol about a week now (maybe a little less). No cracking, some distortion.

But!! And here's the thing that's kind of both confusing and encouraging...if I stick my nose inside the bowl...it still smells like alcohol is evaporating from the wood. If the alcohol had penetrated only "skin deep," so to speak, I would think the smell would be completely gone by now...???

So I'm of two minds about this. I'm not doing it precisely the way Dave says it should be done (especially withthe AnchorSeal) but it seems to me something more than just serendipity is at work.

Thoughts? Anyone?

DW

In the High Desert of Central Oregon

Re: Yet another alcohol question - dilution

Shawn - in ID

>With your extra caution, you are slowing down the ability of water and ethanol to evaporate. I'm not surprised at all that you are still smelling ethanol. Remember also that ethanol will continue to move deeper into the wood while it is also leaving the wood (because you haven't left it long enough to reach full saturation). My comments on structural changes with ethanol soaking also apply here regardless of how fast the ethanol is leaving the wood. All that really matters is that it works for you!

Re: Yet another alcohol question - dilution

Ken from SW WI

>I'd think you can use an antifreeze tester?