Relatively Safe Solvents & Mediums
 

NOTE: ALTHOUGH SAFE KLEAN APPEARED PROMISING, I WAS DISAPPOINTED IN ITS RESULTS. HOWEVER, WE CONTRIBUTORS DID COME TO SOME OTHER GOOD CONCLUSIONS, AS WITH HELP FROM SOME TOP EXPERTS IN THE FIELD. - DOUG

As someone who is quite sensitive (perhaps even allergic) to organic solvents and who is not satisfied with water-soluble oils (particularly the whites, not ground in linseed oil), I have a keen interest in safe, effective substitutes for turpentine.

Gamblin has a good chart comparing the advantages and disadvantages of oil painting solvents...

http://www.gamblincolors.com/materials/solchart.html

However, as you may see from that, none of those solvents -- including Gamsol, Turpenoid Natural

You have a great deal of good information here and I'm going to check it out. Thanks.

I am writing to tell you what I do, not to suggest what you should do/try...

I get terrible headaches if I am in a room with turpentine - even the "odorless" kind, and I've gone through a lot of substitutes and found the following....

"Turpenoid Natural" really messes up my brushes if I don't get every speck of it out when I'm done painting. If it gets mixed up in my paint, it prevents the paint from drying. I don't much like this product.

I do use a citrus-based thinner called Bio-Shield. It does not smell like citrus (thank heavens!) and it does clean my brushes. If it gets mixed up in my paint, it doesn't hurt anything. But basically I use it as a brush cleaner - seldom as part of a medium. The few times that I have mixed it with damar varnish and linseed oil to use as a medium, it has worked well....

I use "Silicoil" as a final brush wash. It is probably lethal stuff, but it does not give me a headache and it cleans my brushes easily and well. (I don't like to use soap and water as I feel it hurts my brushes). I leave the lid on the Silicoil until I am done painting and it is time to clean up. This product should never be mixed with paints.

I do use Liquin as a medium. It is also pretty lethal stuff, except that for some reason it doesn't bother me.

I have a well ventilated studio and can tolerate a lot of chemicals, but never turpentine (or hardware-store paint thinner) in ANY form! :thumbsdow

Is Safe Kleen archival?
 

I just started using Safe Kleen too and though I like the citrus smell and like the buttery feel that the touch of linseed oil gives, I wonder how it will hold up over time in my paintings.

I'd hate to think that in a few years my portraits might turn all green or something. I'd never heard of Safe Kleen before a few weeks ago and the bottle I bought does not list ingredients. It is labeled as an "artists" solvent and medium and I'm guessing the manufacturers would say it will not cause discoloration over time, but I'd just like to be sure. Anyone know what's in this stuff and how it might hold up over the long term?

Thanks!

One more thing about Safe Kleen
 

Oh, one more thing. I was wondering how this stuff might react with Liquin, since it reacted strangely with the Liquin that was left in the little metal cups I use it in. The Safe Kleen caused the dried Liquin to dissolve and bubble up in a way that never happened when I put mineral spirits in those cups. I wouldn't want to see what might happen if I use Safe Kleen in a layer of paint over top of a layer that has Liquin in it!

Heavens! If Safe Klean reacts with dried Liquin in a little metal cup like that...don't take a chance and use it over ANY dried surface containing Liquin!

ALSO

:cool: I use Liquin too and am glad to hear of something (other than blasting caps) that can actually dissolve the dried stuff...i.e., spills on clothing, floor...THANKS FOR THIS INFORMATION!

Karin, I think I'll try your Bio-Shield. Dick Blick.com doesn't have it. Can you tell me where you get it?

Thanks!

I ordered BioShield's Natural Citrus Thinner from:
http://www.bioshieldpaint.com/22.htm

Luckily, there were so many requests from painters in my area, that a local art supply store now carries it. I love this stuff - it is easy on the brain cells...but still use the (lethal) Silicoil as a final brush wash as it is more powerful. (Note: Silicoil is NEVER meant to be mixed with paints).

Thanks, Karin! I bookmarked their site and I'll check it out.

Dear Michele & Karin (and our fellow artists),

According to the manufacturer (whose salesman and chemist I've contacted directly), the only thing left behind after SafeKlean evaporates is a little linseed oil, which will of course oxidize and harden as part of the layer of paint.

So unless they are not telling the truth, there should be nothing to "turn a painting green" over time (a prime concern of mine, too, of course).

I tend to trust the manufacturer, given that their Best-Test rubber cement has been a reliable standby for a great many years.

SafeKlean is also certified to be non-toxic and non-flammable. According to the BioShield website, that product is based on citrus peel; and according to that Gamblin Solvent Chart I referenced (http://www.gamblincolors.com/materials/solchart.html), solvents based on citrus peel have as their active ingredient d-Limonene (4-Isopropenyl-1-methylcyclohexene, according to my trusty old Handbook of Chemistry and Physics); they do dissolve apparently all artists' resins (like only turpentine and SafeKlean); they are used in making mediums (in addition to being used to dilute paint and to clean brushes); they have a flashpoint of 116

If the only thing left behind after SafeKlean evaporates is a little linseed oil (which eventually oxidizes and hardens) it would seem to me that you wouldn't want to clean a decent brush in this stuff and let it sit for 3 months or so afterwards...

If you are saying that you must clean up with soap and water after using SafeKlean Brush Cleaner, I'd say that it is a lot of unnecessary work to have to clean the brush cleaner out of the brush..

I found Weber's Natural Turpenoid to be an awful product that I once mistakenly used to clean my brushes. It wrecked the brush that the "oil residue" dried in. Also when I used it in my paint, the paint "didn't dry" correctly. Sounds like SafeKlean is of the same ilk...

As to the addition of d-Limonene to the BioShield citrus based thinner...I'm willing to trust the manufacturer of BioShield to tell me the truth when they say that this particular product is "non-toxic" and won't hurt anybody....

I get a headache in the presence of turpentine...(after awhile it actually makes me itchy too). I tried a lot of different paint thinners and about 4 years ago, I found BioShield. Because of the way I paint it really works well for me. Whew!

Anyone have comments on Mineral Spirits as a paint thinner and brush cleaner? I know it's not "non-toxic" but how do people feel it works?

Thanks!

Once again, as for questions of mineral spirits, I can only refer to the solvent chart from Gamblin...

http://www.gamblincolors.com/materials/solchart.html

...which is the most comprehensive I've found, and to Ralph Mayer's "bible", The Artist's Handbook.

I'm very glad if BioShield is non-toxic (Does the container carry the "AP Nontoxic" or similar certification label, as does SafeKlean?). All I know is what that Gamblin chart said, that solvents based on citrus peel have harmful vapors (When one source says one thing, and another another, who am I to say?).

As far as cleaning brushes, hands, etc. with soap and water after using SafeKlean, I'm willing to do so for a safe solvent that works like turpentine (which, of course, is very toxic and flammable).

SafeKlean, however, is not "of the same ilk" as Turpenoid Natural, which it was specifically designed to out-compete. In particular, according to Turpenoid Natural's own literature, "since the proportion of Turpenoid Natural in paint mixtures should not exceed 25%, do not use Tupenoid Natural to create washes, glazes or to 'wet' canvas before painting." I was assured from the SafeKlean people that it may be substituted 1:1 for turpentine in the Ralph Mayer standard glazing medium.

Every person's physiology is different, as are every artist's sensibilities. It's good there is a variety of solvents to choose from.

Safe Klean did not work for me
 

Despite assurances from the manufacturer, Safe Klean did not work as a turpentine substitute in making the standard Ralph Mayer painting medium: Although it dissolved almost all the damar resin, Safe Klean formed an emulsion, not a true solution, with the stand oil -- unless I shook the mixture, to form a cloudy liquid, the mixture would separate into two fractions (remarkably not in the same proportions as the Safe Klean and stand oil -- something in the Safe Klean separated out). I cannot recommend Safe Klean for use as a painting medium.

In addition, as Karin pointed out, because Safe Klean contains linseed oil, it is not to be preferred for cleaning brushes. A dedicated brush cleaner, such as the Silicoil she uses (including the clever bottle with the coil in the bottom they sell, to help recycle the solvent), would be preferable, as would a typical solvent.

For cleaning hands, I use "Goop": It is very inexpensive and available at hardware, home, and auto supply stores -- it is used by painters and auto mechanics, both professional and amateur; and because it contains lanolin etc., it prevents hands from chapping, which is particularly good in cold weather (However, because it contains such waxy ingredients, I would not use it to clean brushes). It can also take some paint stains out of clothing.

What then is a safe and effective substitute for turpentine, for clean-up and painting media?

Well, the choice basically comes down to citrus-based products and odorless mineral spirits (OMS). Once again, that chart from Gamblin is instructive...

http://www.gamblincolors.com/materials/solchart.html

...and in addition, you may find similar information from Winsor & Newton (Read the "refresher notes" on solvents and Sansodor)...

http://www.winsornewton.com/Main/Sit...ivencyclo.html

Note that neither recommends citrus-based products (although it should be noted that neither manufacturer sells such a product).

Gamsol, the OMS from Gamblin, has a permissable exposure level of 300 ppm, tied with Sansodor, from W&N: Both are, thus, the safest odorless mineral spirits on the market, as far as inhalation.

The flashpoint of Gamsol is 145 degrees Fahrenheit, slightly lower (and thus more flammable) than that of Sansodor (with a "closed cup flashpoint" of 70 degrees Centigrade, that is 158 degrees Fahrenheit, according to their representative who returned my phone call).

However, to my hypersensitive nose, Sansodor has a slight odor (not entirely unpleasant); whereas Gamsol is virtually odorless -- it is my personal choice.

In the end, if one is to paint in oils -- and to enjoy all their benefits of handling and aesthetic appeal -- then one must either use the water-miscible oil paints (whose whites are ground in oils inferior to linseed and whose handling I personally find difficult) or accept the fact that using solvents is an occupational hazard.

Citrus-based products tend to attack the liver and kidneys; OMS, the nervous and respiratory systems.

The key, as I believe Karin pointed out, is studio safety, for which I refer all to the good advice from Robert Gamblin...

http://gamblincolors.com/safety.html

Good luck to everyone!

Hey Doug, I looked up my BioShield citrus based thinner and it does indeed have d-Limonene (4-Isopropenyl-1-methylcyclohexene in it. I need to rethink my painting materials. A suspected liver and kidney toxicant is something that I wish -at all costs- to avoid!

I now believe that Bioshield is not touting its benefits as a low toxic solvent but because it is biodegradable when poured out in the back yard. Here is the MSDS on this product: http://www.bioshieldpaint.com/24msds.htm I would like to find out the TLV/PPM....but don't know how to read it.

Gamsol does seem to have the highest TLV of any true solvent on the market: 300 PPM.

Does anyone know the TLV/PPM on SafeKlean? Is it considered a true solvent?

I am also looking into this product: # 125 NEUTRALTHIN (Eco-house.com). It is described as "...a practically odourless, general-purpose thinner, brush cleaner and volatile painting medium for oil-based paints and artist paints. This hypo-allergenic formula without essential oils has been used successfully for chemically sensitive persons for more than a decade. However, due to the individual uniqueness of allergic reactions, exceptions are possible..."

I have just written for a MSDS on this product also..

After reading everyone's thoughts on this thread and reviewing all the charts people have so kindly posted links to, I think I will settle on Odorless Mineral Spirits and Liquin as my thinner/painting medium combination.

The only downside I see is that I'll have to dispose of these substances at the local hazardous waste facility and I'll have to keep my window open and my fan running. Can anyone see any other drawbacks to this combination that I'm missing?

What I like best is that both Liquin and Odorless Mineral Spirits seem to have been well tested and I'm not likely to have discoloration over time with my paintings as I might risk from some relatively new medium or thinner that has not been tested by art conservationists.

Hi, my fellow "chemists" (Karin & Michelle)!

Let me say up front that I'm expecting a reply about all this and some other questions soon from a "world-class authority" (which I surely am not).

Isn't it so very frustrating having to go through all this, when we're really not chemists? Even my old high school chemistry teacher seems baffled by some of this obscure organic chemistry.

And the toughest part is that we really get most of our information from manufacturers or retailers (bless 'em) who, of course, are touting the benefits of their own products while downplaying the downside, and visa versa for the products of their competitors (Notice how the Gamblin chart doesn't even mention Sansodor, and how the Winsor & Newton site doesn't mention Gamblin by name). That's understandable, but it makes it difficult for us.

However, I think we're all in the same ballpark now -- even though there's probably no best solution for every problem (or every nose), so we may end up making different decisions...at least we'll make better informed decisions (Thank you for the forum, Cynthia).

That's great you're getting the MSDS, Karin -- I'm glad such data sheets are available. That's really the only way to know the "whole story".

Even then, though, some things seem omitted. Like the MSDS for BioShield really doesn't mention a permissible level (even the Gamblin solvent chart indicates "not applicable"), although it says it may cause irritations (That's a pretty mild warning). It does list the flash point as "1160 F" -- which the Gamblin chart translates into 116 degrees Fahrenheit (I assume that's correct, and that there's some flammability warning on the container, as there is on at least one of the other citrus products I can remember).

However, the BioShield data sheet doesn't mention anything about "suspected liver damage", as indicated in the Gamblin chart. However, yesterday at an art store, I checked products containing limonene (chemically related to the "pinene" of turpentine) -- in particular, Grumtine, from Grumbacher -- and plastered all over the container were warnings of liver and kidney damage.

I also read the following in the Winsor & Newton site...

"Some solvents, particularly hardware grade turpentine or mineral spirits, as well as many of the recently introduced citrus-based solvents for oils, are not fully volatile, leaving all kinds of impurities and detritus behind to sully your precious paint film."

That sounds a lot like the data about Turpenoid Natural.

By the way, all the container for Safe Klean said was that it was non-toxic and non-flammable, although it did bear a nontoxic certification label, so that's probably not its main drawback -- I still don't know how I could mix 6 oz. of that solvent with 1 oz. of stand oil and get it to separate into an approximately 3 oz. bottom layer and a 4 oz. top layer (ugh!).

Anyway, all that info about the citrus stuff sort of put me off of it, even though I consider myself something of an environmentalist (I'm actually educated in the biological sciences, and one of my main thrusts was promoting safe, effective alternatives to chemical insecticides).

Karin, didn't I read in one of your other posts how your child had been poisoned with lead? I admire you as a champion of safe materials (as well as an artist, of course). Although as I learned in chemistry, everything's toxic in certain amounts (ugh).

Incidentally, I like the non-toxic "flake white replacement" from Gamblin; and like you've mentioned in another post, their new, unleaded "Neo Megilp" sounds intriguing (I believe I read that book you mentioned in yet another post, where that man "recreates" paintings by Rembrandt and others, ironically in his own unique style, almost always using a black-oil medium -- even though that new Gamblin sheet says that medium wasn't introduced until the 18th Century. I still enjoyed the man's book -- very "tactile" descriptions of brushwork).

The 3 EcoHouse products listed on their website seem to be a powerful citrus product, a weak citrus product mixed with petrochemicals, and a petrochemical product -- I bet that MSDS shows the NeutralThin to be an OMS. We'll see how it compares to Gamsol and Sansodor.

And speaking of odor, I found Gamblin's Galkyd to have less of a "bite" than W&N's comparable alkyd medium, Liquin; but of course, that's certainly a matter of personal "taste".

And Michele, you've hit the nail on the head, as far as I'm concerned: We artists, especially painting portraits of loved ones and others, have to really be concerned about the longevity of our artworks. Absolutely! So if we have to open a window and fan out the fumes, so be it (or at least, as one of the containers I read said, get some fresh air every so often, and of course taking precautions for fire hazards). And I just hope that the home heating bills don't "go out the window" and that the guys down at the Pep Boys auto shop will take my OMS "sludge" with their motor oil for recycling (The "toxic waste round-ups" are few and far between).

I'll get back with a post about the reply to my questions put to the "world authority" as soon as I can. But for at least the time being, I'm probably going to use an alkyd medium, like Karin uses, and Gamsol and/or Sansodor -- seems like the safest, most effective combination of proven quality.

You're stuck having to use strong solvents when you use natural resins in your painting medium. I would also caution against considering Ralph Mayer's book as tantamount to the Gospel. He had his own prejudices, as do most authors. A lot of new information has come to light in the 23 years since Mayer's death.

All the natural resins have their drawbacks as ingredients in oil painting mediums, and increase the likelihood of problems developing at some point in the future. The most permanent paint films result from the simplest mixtures of linseed oil and pigment. I am less leery of alkyds than I am of damar, mastic or copal, if for some reason I feel a need for a resin in my paint. I find I can paint every bit as well without resins as with them. Our health will suffer less if we can find a way to keep the air in our studio free of solvent vapors. When the paint contains no resins, safflower oil and a rag will suffice for cleaning brushes while one works, and for that matter, afterwards, if it is followed with soap and water. I use different brushes for different colors, and do not clean brushes until I'm done painting for the day. Not only does that keep me from breathing harmful vapors, it keeps my colors cleaner in my paintings.

Virgil Elliott

Mr. Elliott!

Thank you for contributing your uniquely valuable expertise to our thread!

I know what you mean about Ralph Mayer (whom I obviously respect) -- he's perhaps the most quoted authority on painting in recent years; but we really do need another, more updated authoritative work -- I'm sure I speak for all of us in saying that we eagerly await your forthcoming book (Having written some handbooks and software, on other subjects, and having proofread and edited books and articles for other authors, I also know what you mean about an author's "prejudices"; but that's part of what adds to the "personality" of a work, for better or worse).

Since you are also a world-class expert (serving with the ASTM, no less), let me put one of my questions to you -- it is along the lines of your advice, and it also quotes from Mr. Mayer's book. Perhaps there is some common ground; there appears to be some historical precedent...

To my hypersensitive nose (which I seem to have inherited from both parents), even the alkyd mediums are somewhat irritating; and because turpentine is out of the question, I am trying to eliminate all resins from my painting, even though they seem to be standard ingredients in painting mediums since the 18th Century (and my methods of rendering the lifelike translucency of fleshtones requires mediums, in order to apply thin "velaturas" of translucent, not completely transparent, paint).

In an apparently new piece of literature from Gamblin, "Oil Painting Mediums", I read the following: "According to the scientists of the Rembrandt Research Project at the Rijksmuseum, Rembrandt did not use mediums that contain resin varnish. He used the oldest painting medium: a simple mixture of linseed oil and solvent."

Which I believe is like what you are recommending, Mr. Elliott (I believe the addition of solvent is to prevent wrinkling, a common problem with the addition of oil).

I have also just read an article by you, Mr. Elliott, in the website for the ASOPA...

http://www.asopa.com/publications/19.../rembrandt.htm

...in which you describe Rembrandt's medium: "The consistency of the paint was modified by the addition of a medium containing a long oil (sun-thickened linseed or walnut oil or boiled oil) and sometimes a resin, to give it a long brushing quality. Paint exposed to the air for several hours begins to take on this same characteristic, as the oil begins to polymerize."

Similarly, the Gamblin literature says: "In the style of Van Eyck, painters use high viscosity mediums (50% OIL to 50% SOLVENT) to create thin, illusionary surfaces with no brush marks. Linseed Stand Oil, the polymerized oil of the 19th century [I believe sun-thickened linseed oil served a similar purpose previously], mixed with solvent makes a similar high viscosity painting medium that is also slow drying." And previously the literature stated: "Slow drying painting mediums are useful for painters blending colors, such as portrait painters who need more time to blend flesh tones..."

Personally, I find that last point can go either way, given the number of "veils of color" that I must apply.

But still wanting an ingredient like a resin to enhance the "feel" of the medium (as the Gamblin and other literature puts it) and to "toughen" the resultant paint films (although the Gamblin literature also mentions the cracking dangers from natural resins, as you have alluded to), I remembered reading in The Artist's Handbook: "The mixture of linseed oils of various degrees of refinement is a procedure of considerable antiquity...A small amount of a linseed oil of ordinary consistency added to stand oil will impart a certain hardness, body, or solidity approaching that produced by a resin; some of the old effects which may be approximated by the use of Venice turpentine and oxidized oil may also be duplicated by the above mixture, particularly as regards manipulations and brush stroking."

So I am inclined to create a medium that incorporates the features of those mentioned above: Solvent (Odorless Mineral Spirits in this day and age), Stand Oil, and Linseed Oil (and because alkali-refined linseed oil has a reputation for oxidizing to greater hardness than cold-pressed, which I've found to yellow too much -- despite Mr. Mayer's favoring it -- I am now strongly leaning towards including alkali-refined linseed oil in this medium, hoping that the stand oil content will control any "suede effect", and also using paints with pigments ground in alkali-refined oil). Such a medium would have an odor very similar to the paint itself, which I actually find rather pleasant.

I have read further in other literature but have found no other references to the mixing of linseed oils of various states of polymerization (and could chemical analysis of the final, oxidized films of historical works even tell us what states of polymerization the original oils were in when applied? As Mr. Mayer continues in his book, he seems to indicate otherwise.).

If you could give us any guidance on this point, Mr. Elliott, (as to the historical precedent or proportions of linseed oils of various degrees of "refinement" or polymerization in successful mediums) I would be very appreciative. I know of no one who knows more on such subjects than you (or, equally respectfully, the other authority I am consulting).

Thanks again for all your helpful information!

Please note that I have updated the above post as of 10 AM (Pacific Time), as with the inclusion of a link to an article by Mr. Elliott.

Doug,

My Rembrandt article for ASOPA was written several years ago, and is probably incorrect on the point of resins in his medium, according to more recent discoveries made by conservation scientists at the National Gallery, in London. I have since updated that article, excerpted from my book, and the updated version can be seen on the Art Renewal Center web site, at:

http://www.artrenewal.org/articles/2...rembrandt1.asp

That is the danger in committing technical information to print; it is subject to becoming obsolete when new information comes to light to supersede it. This is what has happened to Ralph Mayer's books, and those of all the other authors who wrote on the same subject before him. One must put forth a great deal of effort to stay abreast of the latest discoveries. It is not as simple as reading a book and trusting that everything it contains is the last word on the subject. Knowledge continues to advance.

I believe Mayer was right about mixtures of polymerized linseed oil and raw oil imparting resin-like qualities, and this may well have been done by Rembrandt. He also added ground glass and chalk to some of his paints for various reasons. See my updated article on ARC. I cannot give you the exact proportions, but I doubt they are critical. Too much polymerized oil will increase the gloss. Thus it is for each artist to discover what works best for his or her technique. While it is interesting to know what Rembrandt did and used, we must each paint our own pictures. Only Rembrandt was Rembrandt, and his unique genius was what enabled him to do what he did. The materials he used were incidental to that.

Velaturas can be done without resin ingredients in one's medium, simply by scrubbing the paint on very thinly with a stiff brush. Its consistency can be made more fluid by adding a drop or two of linseed or walnut oil to a pile of paint the size of a large coin, and mixing it in well with a palette knife, on the palette. Scrub a tiny bit of the oil onto the surface of the painting to be painted into beforehand, and wipe off as much of it as possible with a soft rag. The transparency/opacity of one's paints can also be controlled by choosing the pigments with an understanding of the natural degree of opacity or transparency of each. This is preferable, from a structural standpoint, to adding a lot of medium to the paint. Too much medium weakens the paint film. See my other posts for more on that.

One can easy waste much time in an anal-retentive obsession with sophisticated techniques, to the detriment of one's art by virtue of insufficient attention to the aesthetic aspects of art beyond painting technique. These are what should be seen as of paramount importance. The rest is just nuts and bolts.

Virgil Elliott

Virgil,

You certainly live up to your reputation! I don't know of anyone else who could (or would) have answered my questions so thoroughly. I cannot thank you enough, other than to ask that I may somehow be notified when your book is available for purchase. An updated alternative to Mr. Mayer's work is long overdue!

I will worry only if knowledge should ever stop advancing.

The "conflicting" pieces of advice I've gotten before are now pieces of a puzzle almost all in place: I can finally see the picture, and I can now more easily paint in peace.

Thank you,

Doug

From Mr. Gamblin, and more
 

The other world-class expert I posed my questions to was Mr. Robert Gamblin, President of Gamblin Artists Colors Co. and

A Working Solution
 

After receiving so much useful advice, I put it into practice and have eliminated virtually all noxious odors from my studio.

By the easel I have two inexpensive 5-oz. glass bottles with ground-glass stoppers (from Cost-Plus Imports) -- much easier to get in and out of than screw-top jars (an old trick from chem lab) -- in one bottle is baby oil; in the other, Gamsol: While in the "passionate throes" of painting, I can quickly wipe my brush on a paper towel, dip it in Gamsol, and then wipe it again to change colors (and if some of the previous color remains to blend with the next, that usually adds to the "integrity" of the composition). When I have more time, I will wipe my brush, dip it in the baby oil, and then into a series of three jars: The first a Silicoil jar (I bought it previously; I might as well use it now), with a strong solution of shampoo; the next, a mayonnaise jar, with a weak solution of shampoo; and the last, another mayo jar, with just water. It usually takes two go-arounds to thoroughly clean my brush (in the bottom of each jar or bottle, except the Silicoil jar, I have placed a disk I've cut out of a Scotch-Brite

Soy based thinner
 

I just read all the threads on the this subject and was wondering if you have heard about Soy Solve? I just received a free sample from the company and it is supposedly safer than all the substitutes that have been discussed here. I am trying it now and not sure how I feel about it yet. I would love to know if you have already gone down this road.

http://www.soysolv.com

You have all scared me to death of the Natural Turpenoid I have been using for 7 years.

Thanks for all research you have put into this.

Morgan

I'm no expert but I've always heard that artists shouldn't use industrial grade materials because of the impurities they contain that could cause unpredictable results when used in painting. Who knows what color this stuff will turn in a few years? I checked out the website and I didn't see what was in soysolv, other than soybeans. I know what's in my 100% mineral spirits.

Although this thread hasn't been re-visited in five years, confusion and mis-information on the subject of solvents persists. Perhaps some of this information is new since '03?

1. "Turpentine" by definition, is the gum exude extracted from living trees. This includes gum turpentine extracted from Georgia pines, {used in naval stores since pre-colonial times) as well as gum extracted from the European larch, known as "Venice Turpentine" (used in oil painting since Renaissance times) and also Canada Balsam, widely used in the lab to prepare microscope slides, and also of use in certain oil-painting mediums.

2. "Spirits of Turpentine" refers to the clear, water-thin distillate that is collected when turpentine is heated, and is what's commonly known as "turpentine". The solids left behind are rosin (upon which violinists depend), tar, and colophony. A certain amount of these resins and solids is retained in the spirit distillate, and the finest grades of "pure spirits of gum turpentine" are processed three times: hence, "triple distilled".

With the phasing out of linseed oil and natural resins in the paint and coatings industry for commercial and utility purposes, production of top quality pure spirits of gum turpentine has been in decline for sometime, and has been largely replaced by "turpentine" products which are the camp-followers of deforestation in third-world countries. What is commonly available in hardware and paint stores nowadays is a vile liquid, reeking of creosote, which is steam-distilled from slash, stumps, limbs, and other forest wastes. It bears no resemblance to "good" turpentine (what we should be using at the easel) which smells like pine forests after rain.

Pure spirits of gum turpentine is a necessary component to "cut" natural resins for varnishes. Mineral spirits will not effectively dissolve some, while others, such as damar, yield a cloudy, turbid mixture if dissolved in mineral spirits.

The chemistry of pure spirits of gum turpentine is conducive to the drying of oil paint films by introducing oxygen, allowing paint to dry "through" rather than on the surface.

A petroleum distillate, mineral spirits, odorless mineral spirits, and the array of "branded" trade name solvents such as "Grumtine", "Gamsol", "Turpenoid", etc., etc. are all mineral spirits, derived from kerosene, and further refined. As a solvent for cleaning brushes and tools, K-1 kerosene is no more odorous than "regular" mineral spirits, but is more penetrating, and hence a better cleaner. It has a lower vapor pressure than mineral spirits, which means lower emission of hydrocarbons.

"Natural Orange" type solvents contain the oily terpenes extracted from citrus peel waste. Compared to either mineral spirits or pure spirits of gum turpentine, they are extremely active, harsh, volatile, and deleterious to the polymerization of paint films. They can easily remove dry oil paint, and while the citrus odor may be appealing, in a confined space, the volatile hydrocarbons they emit are no safer than those released by either turpentine or mineral spirits. The "cutting", solvent action of these solvents is so extreme, they should not be mixed into oil paints, or any mediums used with them.

Good for you Virgil,

As to which thinner to use, safe practices with solvents will go along way to dealing with them safely. The biggest problem I see with painters is that they leave their solvent cans open. When not in use all thinners should be covered. This reduces the airborne vapors and therefore reduces the risk. Good working habits with most solvents will render them safe enough for most people. Those with severe allergies must be extra careful. The good ventilation and or filter system is absolutely necessary in one's studio. Please paint safely and realize we're using some painters and calls here if not handled properly.

My advice to students is to first see if the effect they are after is something they can get with a simple mixture of pigments. I look at the works of Sargent and Schmid (both of whom are well documented in this area) and for nearly their entire careers (with few a exceptions) they used paint and a little thinner in the early stages of a painting and paint straight out of the paint tube to finish the work. Most of the effects of light, I have to admit, were quite well expressed by these two gentlemen.

If after looking at many examples and finding that the effect you're looking for is quite impossible without the use of mediums, then and only then, do I suggest experimenting with chemistry. My further advice is that you don't become an amateur but a master of chemistry if you expect any of your work the last. If you are unwilling to become a master chemist, my advice is to leave it alone, there are too many variables that you cannot control.

Best of luck to all,
Clayton

Clayton,

Good advice.

Virgil

Gamblin recommends oiling out with a mixture of 50% Galkyd Lite and 50% Odorless Mineral Spirits. How do you both feel about that, Virgil and Clayton?

Michele,

My only reservation would be that if the paint were not sufficiently dry, the solvent could take some of it off. There's less risk if oil alone is used, with no solvent. I blot the excess oil off after oiling out if the paint is fairly freshly applied. Very little oil is needed to serve the purpose of oiling out.

Virgil

Thanks, Virgil.

I have been oiling out with linseed, but in this cool, wet Seattle climate it can take literally weeks for the oil to dry enough for the painting to ship, even if the paint underneath is already dry. Then if it sinks in again, and I have to re-oil, that's another two weeks for drying. Meanwhile, deadlines are looming!

I tested the Galkyd Lite/OMS mixture for oiling out earlier this week and thankfully it's dry to the touch in two days.

Michele,

It sounds like you're oiling out in order to even the gloss instead of to re-saturate the colors and lubricate the surface for continuing to paint on it. If that's what you're doing it for, I suggest spraying a thin coat of retouch varnish instead. Gamblin's Gamvar would work well for that purpose, perhaps thinned a bit more with mineral spirits and shot through a spray gun or large airbrush. It will even out the surface gloss and certainly dry faster than oil. Spraying it on eliminates the risk of the brush and solvent damaging the paint..

Alkyd mediums are not intended to be used as varnishes.

Virgil

Virgil, what's the downside of using alkyds as a varnish? If they're non-yellowing they would never need to be removed, right? Gamblin recommends using that 50/50 Galkyd Lite/OMS mixture as a retouch varnish. What if, after doing that, the painting then had sufficient overall gloss that it didn't need a final varnish?

Not to leap-frog a reply from Virgil, Michele, but a "final varnish" has a function above whatever integrity the paint films that comprise the painting may have, and that is to be a removable barrier between the painting and subsequent wear and tear.

As for the question of whether alkyds yellow, you can quite easily test the materials you are using. Apply a film of alkyd medium to a small piece of glass . . . make a few. Place one outside in full weather, another where it gets a lot of sun in an interior setting, and a third someplace where it's dark and damp. Within a few weeks, differences will begin to show if the material is "fragile". If it's tough stuff, it may take a few months to see changes.

Thanks, Richard!

Michele,

The potential downside is that if the alkyd resin does ever develop a defect of any kind that interferes with the viewing of the painting itself, it will have to be removed, and alkyds require very strong solvents to remove. Thus there would be increased risk to the paint layer. Yellowing is not the only concern, but we cannot say with certainty that it won't yellow over the long term, or crack, or cross-link and become less transparent. It's also a fast-drying substance, and carries the possibility of interfering with the thorough drying of the paint underneath. Of at least equal importance to "fat over lean" is slower-drying over faster-drying. Doing it the other way around can lead to various problems.

I'm sure Gamblin's advice regarding the use of their alkyd medium as a retouch varnish was intended to mean as a couch to paint into while the painting is in progress, as in oiling out over a dried layer in order to re-saturate it to facilitate precise color-matching and to lubricate the surface so new paint will blend into the image more seamlessly. I would still question the advisability of using alkyds for that purpose on any painting whose paint layers have not cured sufficiently. Linseed or walnut oil would be safer choices, in my opinion, with the proviso that as much should be wiped or blotted off as will come off with a dry rag or paper towel immediately after it's brushed on. Very little is needed to accomplish its purpose. Whereas you might get by with using alkyd medium for that purpose, why take the chance? You went to a great deal of trouble to paint the picture, and your collector is probably paying a good price for it. Why risk screwing it up?

Virgil

Richard,

That's good advice. I'd suggest extending the test over a period of at least a year, preferably longer. Some of my tests have involved as much as 23 years. That gives me a pretty good idea which materials will outlast which over the long term.

Virgil

Thanks, Virgil!

Exactly, Virgil. You're definitely right about the length of time involved. Good stuff can take a long, long time for failure modes to appear, and it's really instructive in the meantime.

Testing is something of a necessity, if one truly wishes to know the nature of materials As with so many other things, a wide range of quality often exists, but our tendency is to accept simply identifying materials as species and leaving it at that. That's as naive as identifying a liquid as "wine", ignoring the gulf that separates stuff some homeless guy under a bridge is guzzling from the fine vintages offered in a four-star restaurant.

:)
 

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