Washing linseed oil

[Jacob]

I recently washed a batch of Swedish cold-pressed oil according to the sand-salt-hot water method described by Tad Spurgeon. Along the way the various stages produced what is pictured on http://www.tadspurgeon.com/justoil.php?page=justoil

 

The murky orange-yellow end-result I boiled in a stainless steel pan according to the instructions to get rid of trapped water. The oil clarified perfectly at just over 100º C, and I then took the temperature up to 200º C.

 

When I decated the oil it was crystal-clear, but have a look at the color:

 

 

What's going on??

[MikeC]

http://www.blastedoak.com/blog/?p=195

 

Boiling linseed oil long enough it will turn dark and reddish.  Now that's true boiled linseed oil,  not the crud in a can from the hardware store.    

 

 

I'm wondering did the old Cremona guys put litharge in their linseed oil to make it dry better?  is there any evidence of lead in the old Cremona varnish?  

[Christopher Jacoby]

Lovely color! What a nice place to start a varnish. I'd say go to town.

[actonern]

Jacob:

 

I did 2 litres of the same oil according to the salt and sand method described by Hargrave.

 

I cooked off the trapped water as you did, and then sat the oil in jars.

 

I'm amazed at how much pool sand precipitate still falls to the bottom of the jars... It continues to clarify.

 

You?

[Jacob]

Hi Ernie,

 

I let the oil sit on top of the water for about a month before I removed and cooked it. It is totally crystal clear, there is nothing settling at the bottom.

 

I have had the suggestion that perhaps there was iron the the sand, and that is where the red color comes from.

[Roger Hargrave]

Hi Ernie,

 

I let the oil sit on top of the water for about a month before I removed and cooked it. It is totally crystal clear, there is nothing settling at the bottom.

 

I have had the suggestion that perhaps there was iron the the sand, and that is where the red color comes from.

 

That could be, but in order to wash it, you really don't need to heat oil at all. You don't need sand either; just oil and water in a jar. Shake it up every few days for a week and leave it for a week to settle; sometimes it goes quicker. Siphon off the good stuff leaving the crap. You can wash it more than once if you are really keen. The process is really easy. In fact it’s one of the easiest things about varnish making. 

[tango]

Hi

How much water for wash it only with water, 1-1 oil-water?

Thanks

Tango

[Joey Naeger]

The method I used was to put about 2:1 water to oil in a jar. I'd shake it up and let settle. I then syphoned off as much water as I could and topped off with fresh water. I repeated this until the oil cleared up to my liking.

[Uncle Bob]

I have been using vodka, psyllium husk and glair to wash my flaxseed oil.  4 hours to totally wash flaxseed oil using the fast method from Louis Velasquez.   Not my recipe to give away, but I got it from page 69 of  Louis' Book, 'Safe Oil Painting for Beginners and Art Teachers.' The result is practically scent free, clear, light golden oil and does not haze when chilled down.  OK, one batch I had to cold filter to eliminate haze, but usually it does not haze when chilled.   The only real change to his methods that I have made is to layer a large strainer with coffee filters instead of using a cotton ball to filter with.  Do a small batch the first time or you will probably not be ready to handle the mess this method is capable of making. 

[Guest]

Hi Jacob

I use the same method as you and have never had the oil turn dark like yours. After washing I heat the oil to 100C to clarify. I just washed a batch and because I needed oil to make varnish I did not not let it sit over the winter. Instead after clarifying it at 100C I turned the heat up like spurgeon mentions in the .pdf to 150C and cooked for four hours. It is still very pale and clear. How long did you cook it at 200C?

...very interesting

[not telling]

Can anyone compare the 2-liter bottle method of oil washing with these other methods?  The 2-liter method seems to work...and it's not hard...obviously.  I can do it.

Also, it is my understanding that washing the oil 1-3 times is not enough.  I thought ten times was the low end of what is necessary.  Can anyone confirm or deny that? 

 

 

Uncle Bob...I am super intrigued at what you are doing with the vodka and psyllium husk.  Wouldn't that turn into a jello shot of alcohol and flax oil?  Can you describe the method a little bit without giving away ratios, etc.?

[joerobson]

The method I used was to put about 2:1 water to oil in a jar. I'd shake it up and let settle. I then syphoned off as much water as I could and topped off with fresh water. I repeated this until the oil cleared up to my liking.

After you shake it up, put the bottle in the freezer.  When the water is frozen, cut the plastic bottle open and throw away the water.

on we go,

Joe

[Uncle Bob]

Can anyone compare the 2-liter bottle method of oil washing with these other methods?  The 2-liter method seems to work...and it's not hard...obviously.  I can do it.

Also, it is my understanding that washing the oil 1-3 times is not enough.  I thought ten times was the low end of what is necessary.  Can anyone confirm or deny that? 

 

 

Uncle Bob...I am super intrigued at what you are doing with the vodka and psyllium husk.  Wouldn't that turn into a jello shot of alcohol and flax oil?  Can you describe the method a little bit without giving away ratios, etc.?

The egg white (glair) psyllium and alcohol mix ends up loving all the water soluble components of flax seed oil.  What they don't love is the oil.  So you get this large mass of oily yellow curd that looks like you are working with a brain. 

 

If you pour the oil and plop the mass into a bunch of coffee filters set as tiles on a strainer, you end up with pretty nice oil as a result.   Trying to maximize my gleanings I have submerged and massaged the brain curds in water so more oil would float out.  Probably a waste of time for most folk, but my Scottish Ancestors demand no less of me.

[Joey Naeger]

After you shake it up, put the bottle in the freezer.  When the water is frozen, cut the plastic bottle open and throw away the water.

on we go,

Joe

 

Yes, I forgot to include that step, but that's exactly what I did.

[Jacob]

Hi Jacob

I use the same method as you and have never had the oil turn dark like yours. After washing I heat the oil to 100C to clarify. I just washed a batch and because I needed oil to make varnish I did not not let it sit over the winter. Instead after clarifying it at 100C I turned the heat up like spurgeon mentions in the .pdf to 150C and cooked for four hours. It is still very pale and clear. How long did you cook it at 200C?

...very interesting

 

Hi Ernie,

 

I cooked at 200º C for no more than 15 minutes. The yellow oil started to turn red as the oil was heating up.

[Guest]

Wow...weird. Might not be a bad thing though color wise.

Cheers

[Johnmasters]

Will somebody please tell me what is wrong with the artist's grade linseed oil sold by Grumbacher and others ?

[Peter K-G]

Will somebody please tell me what is wrong with the artist's grade linseed oil sold by Grumbacher and others ?

 

It's too simple, you don't feel like a real violin/varnish maker. It needs to be complex and include a little mysticism

[James M. Jones]

Will somebody please tell me what is wrong with the artist's grade linseed oil sold by Grumbacher and others ?

My last few cooks, I used Weber pure refined lin oil, I tried to wash it .....nothing, the water remained clear , I probably paid a premium for the product ...? but with waist, time and all , and considering the value of the finished varnish ,it seems like a small price , of course I can't claim to have worked so hard. I have washed and cooked with my own,from raw linseed, and I think it is a great exercise to understand process, But I can't argue with the quality of the Weber product   The varnish came out good .  

[Johnmasters]

My last few cooks, I used Weber pure refined lin oil, I tried to wash it .....nothing, the water remained clear , I probably paid a premium for the product ...? but with waist, time and all , and considering the value of the finished varnish ,it seems like a small price , of course I can't claim to have worked so hard. I have washed and cooked with my own,from raw linseed, and I think it is a great exercise to understand process, But I can't argue with the quality of the Weber product   The varnish came out good .  

It is just so available...  I would not know where to buy pure unrefined oil except at a health food store.  Maybe Kremer.  But I will bet the Grumbacher,  Weber,  or Winston Newton refined oils are cheaper and easier to get.  The best painters use it,  and it seems to be fine for them.

[not telling]

My last few cooks, I used Weber pure refined lin oil, I tried to wash it .....nothing, the water remained clear , I probably paid a premium for the product ...? but with waist, time and all , and considering the value of the finished varnish ,it seems like a small price , of course I can't claim to have worked so hard. I have washed and cooked with my own,from raw linseed, and I think it is a great exercise to understand process, But I can't argue with the quality of the Weber product   The varnish came out good .

On your rec., I ordered some. It's under $20 for 473 ml via cheap joe's. Way cheaper than win/new, which does require attention. I guess I might wash it anyway but I'm glad to know it arrives clean. TY

[Jacob]

Will somebody please tell me what is wrong with the artist's grade linseed oil sold by Grumbacher and others ?

 

The problem is seeding, or "worms" with any oil other than cold-pressed raw oil which I've tried. There are countless threads about this.

[not telling]

Of course the refined stuff will have uses if it's not good for varnish--but what if it is good? At least I can play around or practice and it will be significantly cheaper. James is a purist, but if this refined product works then it works, and I'm happy to try it. Why spend days washing oil that you have to pay much more for--up to $10/oz? Due diligence...like playing with both Sennelier venetian turp, and the stuff for horse hooves. I don't know yet if the refined oil will thicken, or even if it acts the same way with more intense heating. Can anyone comment?

...btw...when washing oil I just pour out the water. Am I doing it wrong?

[Conor Russell]

I bought a gallon of the Swedish oil from Kremer recently. I also bought a gallon of oil from my local farmers coop, for €15, sold as a feed supliment for cattle and sheep. I asked the producers what was in it, and they said linseed oil, nothing more. 

 

Now I know that there are different sorts of flax and so forth, but having washed and dried and then cooked both types, I can't see any difference at all, both dry well with no apparent problems. 

 

I'm sorely tempted to re-bottle this stuff and sell it to health fiends at farmers markets as 'Flax Seed Oil', and make myself a fortune.

[James M. Jones]

The problem is seeding, or "worms" with any oil other than cold-pressed raw oil which I've tried. There are countless threads about this.

 I will hardly guarantee success with  the Webber product, but I had no seeding or worms , I did heat the oil to a smoking temp before adding crushed limed white pine rosin, also a batch made  of 'amber' that worked well . I only cooked until I got a foam on top and a faint smoking, then shut off the heat and let it coast to cool in the sand bath,  I did also add kerosene/ lamp oil ,that I tested for full evaporation, and  filtered while warm,  there was a small bit of junk in the filter, maybe these were the 'seeds'??? maybe just got lucky with the four batches .??? The one bad  experience I did have that resembled 'seeding 'was two small dime sized areas that the varnish receded from , I think something got on the surface and acted as a resist , after scrubbing with pumice and water , the next cote went on fine...