Replies

1. 
   1toolman | Nov 26, 2005 06:41pm | #1

   JoeZ,

   Never used PEG with White Oak, but I did a lot of research on drying White Oak.  The basic difference between Red and White oak is that White oak will not let moisture penetrate easily and Red Oak will.  Thinks about it.  I'm sure old Ironsides was made from White Oak.  All Wine barrels are made from White Oak.  If Red Oak was used, the wine would dry out and Ironsides would probably sink.

   PEG will probably seal the surface preventing the cracks during storage, but I would assume as soon as you turn it or cut it exposing untreated surfaces, you will have issues or have to retreat as you cut.

   Interesting question though.

   Tim

   You buy a cheap tool twice and then you're still stuck with a cheap tool!
2. 
   AlanWS | Nov 27, 2005 12:49am | #2

   Hoadley (in Understanding Wood) says a 1" thick slice of red oak in 50% PEG at 120 degrees F takes about a week to soak through, after which it can be dried as quickly as you like without cracking. But white oak will take longer.

   What you are trying to do is not to seal the wood, but to let the PEG replace the water in the wood: since PEG won't evaporate, the wood remains swollen to roughly wet dimensions even after it dries.

   Higher temperature helps it soak in faster. For a 2"-3" thick walnut disk in 50% PEG, it takes 45 days to treat at 70F, but only 14 days to treat at 140F.

   If the PEG is less concentrated than 50%, it will take even longer.

   
   

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   Edited 11/26/2005 4:50 pm by AlanWS

3. 
   DennisS | Nov 30, 2005 06:39am | #3

   Joe-

   At the risk or diverting attention from you primary question, I've always wondered about this PEG stuff. It's PolyEthyleneGlycol if I understand correctly. Now EthyleneGlycol is none other than antifreeze. How then does PolyEthyleneGlycol differ from antifreeze? And if it doesn't differ all that much, would it not be food safe?

   Curious minds need to know. (grin)

1. 
   JoeZ | Nov 30, 2005 05:08pm | #4

   Dennis,

   Yes, ethylene glycol is antifreeze.  Poly-ethylene glycol is, simply put, a bunch of ethylene glycol molecules all linked together.  And though it seems like a simple difference, it changes the chemical properties of the material.  Ethylene glycol (antifreeze) is toxic; polyethylene glycol is not.  Ethylene glycol is a liquid at room temperature (and a lot lower); PEG is a solid that will dissolve in water. 

   There are probably several other differences, but these are the most important for woodworking applications.

   Joe

1. 
   DennisS | Nov 30, 2005 07:18pm | #5

   OK - thanks, Joe. I realize it's probably a lot more complex than that but no sense in starting a chemistry lesson here.By the way, did you ever read or hear about liquid dishwasher soap being used as wood stabilizer concept? I tried it on some green cherry once with marginal results. The fellow that came up with the idea was looking for something that wouldn't affect his finishing the way PEG does, or at least in a way he objected to. I've never used PEG so can't comment on his objection to it.

2. 
   AlanWS | Dec 01, 2005 01:54am | #6

   PEG is really quite different from ethylene glycol, in the same way as a freight train is different from a single car. There are actually many types of PEG available, differing in how long the train is. If you use it for stabilizing wood, you want PEG-1000 (which has on average about 23 ethylene glycol units).As far as toxicity goes, while ethylene glycol is quite poisonous, PEG is not. It may actually be safer to eat than detergent, though I wouldn't recommend either.