Thursday, September 03, 2015

Hand Refined Linseed Oil from Flax oil

American Goldfinch  11"x14"

I just completed my first successful batch of hand refined linseed oil out of organic, cold-pressed Flaxseed oil.  It is beautiful and I'm over the  moon excited to make some paint and test it out to learn it's unique properties.  

I also have half of my new oil thickening in the sun, I plan to use that bodied oil for my hand made calcite putty medium.  I've learned that combining calcite with lead white creates Ceruse or 'lootwit' and was used by Rembrandt and Velazquez for translucent passages.  I also purchased some barite, after learning it is even more transparent than calcite and was used by the Old Masters with lead white as well, it was called Venice Ceruse, or Venetian white. 

here is the good quality oil I purchased to cleanse and make into linseed oil:

I've combined the oil with water, salt and sand.  A chemical reaction takes place and the mucilage and impurities are separated from the flax oil, they settle into the sand on the bottom, the cleansed oil floats above the salt water layer:  ingenious!

After several mixes and changes in water/sand/salt I have the resulting oil, a bit cloudy from water particles still in the oil but cleansed of the mucilage, fatty acids (Omega 3s) and impurities that slow drying and yellow over time:

After setting in a glass tray in the sun for a few days to clear, we have the finished oil!  My own batch of hand refined SRO (salt refined organic) linseed oil will now have its own unique personality compared to the commercial hot pressed, alkali-refined linseed oils.  Commercial linseed is stripped of all the properties that create unique painterly effects.  This is due to the fact that they are refined in the same manner as vegetable oils are refined for consumption.  The qualities that are desirable in oil painting are stripped from the oil in the commercial process to create a long shelf life.  Hand refined SRO oil keeps all the good stuff and eliminates the impurites and mucilage, resulting in an oil that the older painters prized in their hand made materials. 

My oil will create long, adhesive paint as opposed to 'short and bouncy', it will not yellow and will dry much more quickly now and to a strong, hard film.  These are exactly the characteristics I'm looking for in my painting practice.  If I were to heat this fresh oil to 100C on my stove for an hour, the resulting oil would create paint that is short, bouncy and dense.  My other half (that is thickening in the sun at the moment) will also have unique tendencies and rheology in my paints and mediums.  I love learning all the different painting qualities I can create, and am in complete control over, by processing my own materials.

ta da!


Liz Stewart said...

What were the amounts of sand and salt that worked for you?

Sarah S said...

For this batch I mixed two cups of oil with 1/2 cup of sand (sand bought at a specialty shop for pool supplies) and 3/4 cup pickling salt mixed in four cups hot water. You need to exchange the water/sand/salt three times so you need to take that into account when calculating final amounts. I followed the instructions from Tad Spurgeon, which you can read on-line.

steve said...

Did you add chalk or lime when setting in the sun?

Sarah S said...

No, just oil. It thickens pretty fast in the NM summer sun. The sun oil proves to be the fastest drying when added to mediums.

Unknown said...

I just learned this and tried it, being close to the sea I used twice sifted beach sand and boiled ocean water. Then strained thru a coffee filter over a sink screen. Super easy to do (spent a day mostly shaking and waiting) It worked great!! Actually it seemed so easy I started Looking to see if other people's results were similar and came across your page. Awesome!
Great page, thank you

HS said...

Hello! I'm in the process of doing this but using a cold-pressed linseed oil for horses. Did you have to leave the oil directly in the sun (outside) or can you leave it in a jar on the windowsill? I might have to try again with a higher quality oil, I'll see how it goes. And how coarse is the sand you used? I got some quartz sand that is quite fine, I wasn't sure if it should be fine or coarser?! Thank you for sharing your process, it's so helpful to see!! :)

Sarah S said...

Hi HS, making oil is a lot of fun don't you think? As for oil, just read the ingredients, it's very important there are no extra additives. use a fine grain sand. As for sun oil, I leave it outside in the sun. I use a flat glass baking dish and use spacers with a clear glass on top. I set it outside everyday until it's the proper consistency.