Replies

1. 
   dryhter | Dec 01, 2005 11:08pm | #1

     Linseed oil comes from Flax Seeds. If you press Flax seeds, the oil is called Flaxseed oil.If you press it using chemicals, it's Linseed oil.If you process the oil and add chemicals(Dryers), it's called "Boiled". Raw doesn't dry and stays gummy, Boiled dries.

2. 
   SteveSchoene | Dec 01, 2005 11:16pm | #2

   Metallic driers.  Raw linseed oil takes almost forever to cure.  The driers are added to promote curing.  Boiled has always been a misnomer, though early BLO was heated to help it encorporate the lead used as the drier.  Of course, lead hasn't been used for decades.  According to Bob Flexner, another variety polymerized oil, is derived by heat treatment, but without oxygen, in order to start the crosslinking.  An example with linseed oil is TruOil, used on gun stock finishes. 

3. 
   MarkRD | Dec 02, 2005 03:35pm | #3

   Cool, I always thought "Boiled" meant that the solvent was somehow boiled off.

   ANd from personal experience :-( BLO takes forever to cure. I have learned that you can speed it up by warming the piece (I have a gas fired "wood stove" that works great or I've used a portable space heater).

   I've also learned to read can labels more carefully :-)

   Mark

   Measure it with a Micrometer,

   Mark it with Chalk,

   Cut it with an Ax.

   Visit my woodworking blog Dust Maker

1. 
   sharpblade | Dec 14, 2005 01:21am | #4

   The key with most oil finishes (BLO & others) is to lay the finish on generously, let it soak in the wood, then after a wait (depends on the oil) rub all the excess off with a rag. Can't let a thick film of the stuff sit there and expect it to dry. It will stay gummy and a pain in the uknowhere to remove.

4. 
   kesac | Dec 19, 2005 05:14am | #5

   Boiled linseed oil will cure.  Raw will not.

1. 
   HowardAcheson | Dec 21, 2005 02:36am | #6

   BLO will cure--really polymerize--into a thick gummy substance but it never hardens.  If you put a thickness of BLO on a piece of glass and let it stay for a week, it will somewhat harden into a wrinkly, very soft gunk.  That's the reason that excess must be wiped agressively. 

   I think of BLO as more of a grain highlighting treatment than a finish.  Used alone, it has almost no moisture or moisture vaper protection nor has it any abrasion protection.Howie.........

1. 
   kesac | Dec 21, 2005 07:31am | #7

   Well, I spent lots of years in the Marine Corps, wiping down the stock of an M14 with linseed oil still hot from the stove.  Those stocks polished like glass, and with ever abuse dished out by kids who knew the damage wasn't coming out of their pocket whether the rifle was drug thru a swamp, stacked in the rain all night, or whatever.

   That finish sure felt hard and dry.  I guess if you'd have been around to tell us in '68, we'd have known better. Of course, we also didn't have japan drier in ours, that might have made some difference too.