Never used Soluvar, but I just looked around the Internet… Seems that Soluvar hates OMS, either as thinner or remover. Must used mineral spirits or turps, which are more powerful solvents.

Alas, Bill, you are guilty of the common problem of not reading the instructions! (Believe me, we’ve all been there…). Nothing wrong with the Soluvar. Instructions on the Liquitex website are pretty clear – don’t use OMS, but rather Mineral Spirits or Turpentine. Here’s a link:

http://www.liquitex.com/archivalremovablevarnish/

Don

Hmmm. OMS is weaker than regular mineral spirit after the refinement reducing its solvent capability. Thats why they state this three times in that article shown.

Old thread
https://www.wetcanvas.com/forums/archive/index.php/t-380823.html

Soluvar is acrylic solvent varnish. It will never dissolve into OMS. To remove Soluvar, artist must use the same solvent as for removing of Dammar varnish.
Also, soluvar is acrylic polymer varnish rather than “low molecular weight resin” varnish. That means, when artist use wrong solvent, soluvar can absorb it partially and forms gel and that looks like skin. To remove old soluvar, at least regular turpentine should be used. Or a mixture with toluene, turpentine e.t.c.

General rules (not absolute):

In various kinds of mineral or natural spirits, including turpentine, kerosene, gasoline (petrol), naphtha, paraffin oil, whatever: Odor is caused by cyclic hydrocarbons (such as benzene, and many others). Linear and branched hydrocarbons, without pentane or hexane rings, are odorless. This is without reference to non-hydrocarbon compounds that can naturally or artificially add a scent.

An odorless mineral spirit is one that has been refined (or chemically built up) in such a way as to eliminate cyclic hydrocarbons. As a side benefit, this may also reduce carcinogenicity.

The solvent power of mineral or natural hydrocarbon spirits, is largely a matter of molecular size, which relates to molecular weight. The smaller the molecules, the more they can squeeze between and dilute the molecules of whatever they are trying to dissolve.

However, smaller, lighter hydrocarbons also have a lower flash point, meaning that they will more readily vaporize and burst into flame when an ignition source is nearby. If that were not a problem, gasoline would make a great brush cleaner! (Don’t do it.)

Thus, the more the solvent power, the greater the fire hazard. Exception: Chlorinated hydrocarbons can have small (but heavier) molecules with high solvent power and low fire hazard. Examples are carbon tetrachloride and methylene chloride. But chlorinated hydrocarbons often have great health hazards from inhalation or contact, so don’t use them in painting.

OMS is a mixture of various non-ring hydrocarbons (and possibly other compounds). If it is formulated to have small molecules and a low flash point, it will have high solvent power but be flammable. Or, if it is formulated another way, it will have lower solvent power and be “combustible,” meaning that its flash point is about a certain legally specific temperature. Gamsol, and many other OMS used for oil paints, are in this category of low solvent power and high flash point.

Turpentine has higher solvent power, and lower flash point. It is flammable. This is why it can dissolve some varnish resins that safer OMS cannot dissolve. It is also why turpentine is more of a fire hazard. The health issues are a different matter.

In the USA, the post office (USPS) will allow air shipment of combustible liquids, if safely packaged and for consumer use. It will not allow air shipments of flammable liquids. See here. The flash point of Gamsol is 144F (combustible, can be shipped by domestic air). The flash point of turpentine may be as low as 86F. It is flammable, and cannot be shipped by air no matter how packaged.

If turpentine were somehow made odorless by the removal of ring hydrocarbons and naturally-occurring scents, it would nevertheless retain most of its solvent power, and still be a fire hazard due to flammability.

If you add lemon oil to Gamsol, it is not longer odorless, but it still has lower solvent power and is less of a fire hazard. In fact, “aromatherapy” lamps sometimes use a liquid that is similar to scented Gamsol (but not exactly the same, so don’t do it this way).

Part of the requirements of an appropriate varnish is that it dissolve easily, and with the weakest of all solvents, OMS. Stronger solvents tend to dissolve the surface of the painting, as well, and that’s not my goal.

I don’t want to use a varnish that can’t be removed easily. If I am required to use Turpentine, Toluene, White Spirits, etc. merely to remove a simple, final varnish, I won’t choose such a varnish.

Hard resins, such as copal, and amber, are fine to use as ingredients [I]within[/I] a painting, but certainly not on top of it.:)

To each their own!

I love the look of amber varnish on my paintings, and I dont want it to be removed

for mosst artists I would recommend gamvar or similar but it all comes down to aesthetic opinion