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