Replies

1. 
   UncleDunc | Nov 18, 2002 08:47am | #1

   I think it's clear that that can is over the hill. The next question is was it 100% tung oil or was it a tung oil finish or tung oil varnish? The 100% oil cures by polymerization, not by solvent evaporation, so any of it that is still liquid hasn't polymerized yet and should still be good. Even if it forms a skin, the liquid under the skin should still be usable. If it's jelled or gummy, I wouldn't risk it. Tung oil isn't that expensive compared to the time you have in a piece when you get to finishing.

   
   

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   Edited 11/18/2002 12:52:01 AM ET by Uncle Dunc

2. 
   mrles | Nov 18, 2002 08:57am | #2

   Is this pure Tung oil or varnish with Tung oil in it? When I apply pure Tung oil I wipe it on with a cloth, let it set a few minutes and remove anything left on the surface, it is absorbed in the wood mostly. I can't see it getting scaly, Whatever it is I would chunk it. 

   When I was introduced to Tung oil 30 years ago I was told to put clean rocks in the remaining finish to fill the bottle to keep it from air drying. I've never had any go bad.

   Good Luck God Bless

   les

1. 
   Marcello | Nov 18, 2002 10:18am | #3

   You must use your cans quiker than it takes the stuff to go bad.  I've had some on my shelf, using a little at a time, and it gells up in about a year.

1. 
   PlaneWood | Nov 19, 2002 03:47am | #4

   I pour what tung oil I need out into a cup then quickly seal the can back up, after first squirting in some gas from my propane torch.  If you don't remove the oxygen some way, the tung oil will jell within a few months.

   Also, there are two kinds of 'pure' tung oil.  Raw, and polymerized.  The raw will make a less glossy finish than the polymerized.  Polymerized tung oil has been cooked at a high temperature.  Sorta like raw and 'boiled' linseed oil, except raw linseed oil takes forever to cure.  And, they don't really boil linseed oil anymore.  They just add dryers.

   PlaneWood by Mike_in_KatyPlaneWood

3. 
   bobhallsr | Nov 19, 2002 07:51am | #5

   When I worked with an ink manufacturing facility we had a lot of varnish components. Raw tung was called 'china wood oil'. I never tried it as a varnish because I didn't want to calculate how much drier I might need. Just lazy, i guess. I did try using 'bodied tung oil' (BTO) It was thickend by heating it which presumably partially polymerized it. Any way, it left a matt finish which I didn't like. Lesson ;earned: Don't try to make your own varnish. Buy it from a manufacturer who knows how.

   I guess that the rest of the lesson is: don't try to rework old varnish, it's too much like making your own vrnish.

   BJ

   Gardening, cooking and woodworking in Southern Maryland