Anyone heard of P.E.G. ?

[Nicholas Briggs]

Hello all,
I'm new here, and thrilled to have found such a forum. I am in search of something called P.E.G. (or at least i think that's what it's called). Back when I was in highschool my woodshope teacher mentioned it. He said it was a salution you could soak coarse woods in normaly used for palm. Anyone heard of this stuff or have any idea where I could find it?

[Chris Friesen]

Hello all,
I'm new here, and thrilled to have found such a forum. I am in search of something called P.E.G. (or at least i think that's what it's called).

What you're looking for is called polyethylene glycol, and it can be used to stabilize green wood.

I'm sure you can get it many places, but one source is Lee Valley Tools:

http://www.leevalley.com/wood/page.aspx?c=1&p=20080&cat=1,190,42942

[Frank Chaffee]

Start here...
http://www.treesearch.fs.fed.us/pubs/9634

[Nicholas Briggs]

Awsome! Thank you both very much!

[Mark Singer]

A song by Steely Dan:confused:

[Hans Loeblich]

Isn't that what anti-freeze is made of?

[Bill Boehme]

Isn't that what anti-freeze is made of? No, anti-freeze is ethylene glycol (which is poisonous) and various other things like rust inhibitors and buffering agents to maintain the desired pH. PEG (polyethylene glycol) comes in a wide variety of molecular weights from about 200 up to about 20,000. It is inert and non-toxic. The lower MW polymers of PEG are used in some food products like soft drinks, dish detergents, and cosmetics. PEG1000 (the molecular weight is 1000) is the polymer that is used by some woodturners. The very high MW PEG is insoluble in water and is like a hard plastic.

At room temperature, PEG1000 is a solid white block with a waxy feeling. It can be dissolved in very hot water by cutting the PEG into small chunks and stirring until your arms fall off (almost). It can only be used to soak freshly cut (within a few hours of cutting) green wood (dead wood does not count) and it must be soaked for something like three weeks, if I remember correctly.

PEG was a big flash-in-the-pan a few years ago, but its popularity quickly faded. Its benefits of stabilizing green wood from cracking is greatly outweighed by the darkening and dulling of the wood's normal luster and the fact that most finishes will not work with it. Most film finishes will just turn into a non-drying gummy mess. And the wood seems to always have the same tactile sensation that you get when changing oil in your car.

There is a bit of misunderstanding in the woodturning community about the use of PEG and some turners believe that it is used to speed up the drying of wood. That is incorrect -- it is only used to stabilize wood from cracking and shrinking, but if anything, it greatly prolongs the drying process.

Bill

[Bob Hallowell]

I thought PEG was Al Bundy's wife :)

Bob

[George Tokarev]

Hello all,
I'm new here, and thrilled to have found such a forum. I am in search of something called P.E.G. (or at least i think that's what it's called). Back when I was in highschool my woodshope teacher mentioned it. He said it was a salution you could soak coarse woods in normaly used for palm. Anyone heard of this stuff or have any idea where I could find it?

If you look at the list of ingredients on the labels of most cosmetics you'll find that PEG in various polymeric weights is commonly used as a humectant. The 1000 version was used by Ed Moulthrop to produce the monster end-grain bowls he became famous for. The best book is Working Green Wood With PEG , if you want to try it. It's a double alcohol, which means there are two -OH groups on it to make it miscible with that other polar solvent, water. But unlike, according to proponents, ethanol, Raoult's law works with this stuff. With a higher boiling point than water, it remains behind as the water evaporates, "bulking" the wood fiber, or your skin.

Problems mentioned already include darkening, hygroscopic nature, and the difficulty getting a finish on the wood. I use it for my carving mallets, because it allows me to use wood with the heart in with little danger of cracking, pulls water from the air to keep the fibers expanded, imparting a "dead blow" property to save my elbow, and adding a bit of extra weight as well. About the only finishes that appear to work well and give a smooth surface are the isocyanate types, and their adhesion is helped by wiping the surface with acetone. The Moulthrops used phenolic (an alcohol) varnishes, If I recall correctly. Old Watco was phenolic, and didn't look too bad.

Ethylene glycol, what used to be the useful ingredient in antifreeze because, once again, of its higher boiling point and lubricating ability, has been used to stabilize wood. Unfortunately it's a small enough molecule to be metabolized, and can poison you. It also has a sweet taste, which was the source of a big scandal in the German white wine industry a number of years back, where it was added to low-sugar wine to improve the taste, and why your dog will lap it up if you spill it, with possibly fatal outcome. The larger polymers are used as intestinal irritant/lubricants in laxatives, and are indigestible.

The most often recommended soaking dilution is 50/50 by weight, and soak times, once again in defiance of the ethanol principle, depend on temperature and are measured in weeks per inch depending on grain orientation and thickness. I do the 3-4" diameter mallets three months at 20C. If I wanted to kick it up to 40C, I could almost halve it. You must catch the wood before it begins to shrink, which is to say above the FSP of about 30% moisture by weight for it to do its best work. But you can expect minimum distortion and no checking if you allow the stuff long enough to penetrate. Of course you still have to dry it afterward.

A curiosity, but like a lot of fads, one which depends on good science to be effective. With the exception mentioned, I don't use it any more. The acrylics used as bulking/stabilizing agents now will allow you to finish things with better outcomes, but at a monetary penalty. Better to dry observing good procedure and allow for shrinkage, in my experience. Then all options except full size of dried piece remain open.

[Doug Collins]

Bill, I love your explanations...Not just the 'what' but the 'why'.

[Jeffrey Fusaro]

I thought PEG was Al Bundy's wife :)

Bob

ROFLMAO!

good one! my kinda humor!

i'm sending you the bill for having the stains removed from me spitting coffee all over my keyboard and monitor!

[Dan Gill]

A song by Steely Dan:confused:
I still have that album somewhere. Of course, I don't have a working turntable to play it on . . .

[George Conklin]

Bill, I love your explanations...Not just the 'what' but the 'why'.

Ditto!!!!!

[Bill Boehme]

I appreciated George's more detailed technical explanation. Chemistry is not my forte -- I just stick with the electrons (EE) and leave the rest of the atom for the physicists and chemists.

Bill