Washing linseed oil

[violins88]

I have tried washing linseed oil. To do what I do, get a plastic drink bottle, pour some linseed oil in it. Add water. Replace cap. Shake well. Invert and poke a small hole, using a needle in the bottom end of the bottle. Place the bottle upside down for a few hours and watch the oil and water separate. You might get something similar to what is in the pic. See the cloudy water? Here is your question. What is in this water? Some violin makers might say mucilage. Now hold the bottle, upside down, over the sink. Loosen the cap and let the water only run out. Put your finger over the tiny hole and add more warm water and shake, as before. Repeat 10 times. Is the water still cloudy? If not, why not? What is making this water cloudy? How many times would you have to repeat in order to get clear water?

If you complete this exercise, move to the head of the class.

[MANFIO]

Good. What is the brand of the linseed oil you have washed?

[violins88]

Good. What is the brand of the linseed oil you have washed?

The brand is E-Z Raw Linseed Oil.

Wow. Quick response.

[JCHungerpiller]

The first time I did this, my wife, who had kindly purchased the linseed oil, was watching over my shoulder and commented: "hmmmm, so now I know what $25 worth of ruined linseed oil looks like."

[Johnmasters]

What is making this water cloudy? How many times would you have to repeat in order to get clear water?

Another interesting question: After a number of washings, the water looks clear. If you make the water basic, will it remove something else? How about acid? If you want to remove the most non-oil stuff, which should you use? pH > 7 (basic) or pH < 7 (acid) ?

Would it help to add soap to the water? Why or why not? What about soap with base or acid?

[GMM22]

I am no expert in linseed oil, but I do recall reading somewhere that cheaper grades often contain stuff that is not linseed oil, like oil of weeds.

E-Z Raw does not sound like a top artist grade linseed oil, but I could be wrong. Personally, I would not consider the experiment too interesting until I had established that the brand chosen to test was absolutely top notch to begin with.

Let's put it this way, how much did your E-Z Raw cost, and for what quantity?

[fiddlecollector]

Another interesting question: After a number of washings, the water looks clear. If you make the water basic, will it remove something else? How about acid? If you want to remove the most non-oil stuff, which should you use? pH > 7 (basic) or pH < 7 (acid) ?

Would it help to add soap to the water? Why or why not? What about soap with base or acid?

In general,alkali will remove free fatty acids ,Acid will remove the mucilage(preferably sulphuric)

The mucilage consists of a number of things like protein,wax,nitrogen compounds,gluten,etc....

[MANFIO]

Yes GMM22, I was thinking the same... The linseed oil I'm using now is from Kremer, cold pressed, from Sweden, 36 bucks the liter. I don't wash it, and it seems many members here don't wash top quality oil too.

Some old Italian manuscripts mention boiling linseed oil with water to purify it.

[violins88]

Another interesting question: After a number of washings, the water looks clear. If you make the water basic, will it remove something else? How about acid? If you want to remove the most non-oil stuff, which should you use? pH > 7 (basic) or pH < 7 (acid) ?

Would it help to add soap to the water? Why or why not? What about soap with base or acid?

John,

So, you HAVE done this experiment? I mean until the water is clear?

So, if I try to answer your questions, (I mean if I get some 11 year-old to do it), can the boy/girl use white vinegar and Lime?

Thanks

[violins88]

Let's put it this way, how much did your E-Z Raw cost, and for what quantity?

Cheap oil at the hardware store. 0.946 Liter.

[MANFIO]

I would not use cheap oil (washed or "dirty") to make violin varnish.

If you start with top quality materials your chances of making a good varnish are bigger.

[violins88]

I would not use cheap oil (washed or "dirty") to make violin varnish.

If you start with top quality materials your chances of making a good varnish are bigger.

Manfio,

Have you used walnut oil? From the health food store? I have some of that. Does it require washing?

[MANFIO]

No, I have not used walnut oil, but I'm very curious about it... A member here made the Marciana Recipe varnish using walnut oil and it worked well.

[GMM22]

Cheap oil at the hardware store. 0.946 Liter.

Then I think the results of such experiments are inconsequential, but that is not to say devoid of information, as you might well be demonstrating the presence of impurities. Start with the highest quality artist grade linseed oil for your experiment, otherwise trying to pinpoint impurities is futile. As Manfio noted, cost should run upwards of $30 a litre. Such oil is far more pure and refined to meet artist's high expectations.

[GMM22]

I think I like walnut oil better, but I usually use it in a much simpler way than for varnish. I recall speaking to two experts in historical artist's materials who provided compelling argument that walnut oil may have been prefered by a few of the greatest renaissance master painters; Da Vinci was one name that came up. My theory was, if it was good enough for Da Vinci, it is good enough for me . Walnut oil is more transparent, and does not have a yellowish body color to it. The stuff I have is more like mineral oil in color.

[violins88]

I would not use cheap oil (washed or "dirty") to make violin varnish.

If you start with top quality materials your chances of making a good varnish are bigger.

Manfio,

Would you care to say which recipe or kind of recipe you use? Darnton Mastic Varnish?

Thanks,

[violins88]

I think I like walnut oil better, but I usually use it in a much simpler way than for varnish. I recall speaking to two experts in historical artist's materials who provided compelling argument that walnut oil may have been prefered by a few of the greatest renaissance master painters; Da Vinci was one name that came up. My theory was, if it was good enough for Da Vinci, it is good enough for me . Walnut oil is more transparent, and does not have a yellowish body color to it. The stuff I have is more like mineral oil in color.

GMM22,

Have you made varnish? Care to say which version?

Thanks,

John

[Wm. Johnston]

Cheap oil at the hardware store. 0.946 Liter.

Is this the "Boiled Linseed Oil?" If so it was probably not actually boiled. Boiled linseed oil from the hardware store means linseed oil plus driers. If it's not called boiled linseed oil then it's still likely to have driers of some sort in it. Read the label carefully, if it doesn't say anything about driers then I would look for a materials safety datasheet before doing any experiments with this stuff, I wouldn't want try to cook varnish with oil that already contained heavy metals.

[MANFIO]

Thanks for the input GMM22.

The recipe is on a manuscript on the Biblioteca Marciana, in Venice, and is dated 1550 "circa":

Item Vernice che si distende come olio et seccha presto et è molto lustrante et bella et pare uno specchio di vetro et per stare alla cosa et sopra liuti et simile cose è mirabile;" ma nel testo, queste "simile cose" sono descritte come manufatti in legno, ferro, carta, cuoio e opere dipinte:

"Togli per una misura: una libra d'olio di linseme, et quocilo come si fà in una pignatta invetriata netta, poi vi metti su mesa libbra di pece greca chiara et bella et polverizzata et mesta quando la metti, tanto che si incorpori bene a fuoco dolce, poi vi metti su mezza libra di mastice macinato, et quando lo metti perché ei rigonfia leverai però la pignata da fuoco et mettilo su a poco a poco mestando et incorporando bene, poi torna la pignata al fuoco et mesta tanto che si solva ogni cosa bene, poi mettivi quanto una noce di allume di roccha arso pesto et mesta che si solva et incorpori bene poi lievala dal fuoco et colala per peza lina vecchia et serbala, et per legname, et per ferro et per carta et corame et per ogni dipintura et lavoro farà un opera bellissima et per stare alla aqua, et quando ti pare soda stempera con olio di lino come si fa etc. ".

Basically it's 2 parts oil, one part colophony, one part mastic. I can't find a translation now but if you make a search on this forum with "Marciana varnish" you will find more information. I use this varnish for the ground and first coat only, then I follow with Doratura Rossa, from Magister Products.

[violins88]

The linseed oil I'm using now is from Kremer, cold pressed, from Sweden, 36 bucks the liter.

According to this article at the end of the page, it says Sweden imports most of its linseed oil from Argentina?

Comments? I know nothing about strains of plants. Do American growers have access to the same seed types, or are they patented and regulated?

[joerobson]

88,

Flax is flax as long as the flowers match. [The Canadians grow good stuff, so do the Argentinians.] Blue and brown flax make good oil for varnish. Yellow flax is a hybrid genetically engineered for food use. I agree about the boiled linseed oil...raw oil + driers...not for varnish. Raw linseed oil is what you need. No matter the price: test the oil to see if it will dry. If it does then go through the trouble of washing.

The cloudy stuff is organic remains of the pressing. Try freezing the separated oil and water. Throw away the ice cube and do it again until the water is clear.

My kind of fun.

On we go,

Joe

[GMM22]

GMM22,

Have you made varnish? Care to say which version?

Thanks,

John

Nothing worth mentioning. My experience in varnish making is limited to some trial and error (mostly error).

[violins88]

88,

Flax is flax as long as the flowers match. [The Canadians grow good stuff, so do the Argentinians.] Blue and brown flax make good oil for varnish. Yellow flax is a hybrid genetically engineered for food use. I agree about the boiled linseed oil...raw oil + driers...not for varnish. Raw linseed oil is what you need. No matter the price: test the oil to see if it will dry. If it does then go through the trouble of washing.

The cloudy stuff is organic remains of the pressing. Try freezing the separated oil and water. Throw away the ice cube and do it again until the water is clear.

My kind of fun.

On we go,

Joe

Thanks Joe. That is useful information. I am going to see if I can find a farmer here in NC to grow some flax. Special flax. Not in fields rotated with rapeseed. No contaminants. Of course it may cost $36 per Liter, but I won't have to pay shipping.

On second thought, maybe I will just buy YOUR varnish.

[upnorth]

Wood finishing enterprises has varnish makers linseed oil. From their website for $8.00 for a liter. It is washed and refined. :

"Varnish makers linseed oil has been refined to remove the “break” so that it will not become cloudy on heating to make varnish".

Manfio, why don't you use the Marsiana varnish for your colored layer? Can't you just add the pigment to it and have a good colored varnish. What are the properties in Doratura Rossa that make it desirable to you?

[violins88]

Wood finishing enterprises has varnish makers linseed oil. From their website for $8.00 for a liter. It is washed and refined.

Thanks for the link. I will check it out.