Martin F. Weber "Cleaning Solution for Oil Paintings

​It was a mixture of pure gum spirits of turpentine, petroleum solvent and alcohol. Still available in this category is W&N Artists’ Picture Cleaner, which contains D-Limonene and pine oil. I will defer to the conservation professionals on the topic of the wisdom and safety of using these products.

I am very happy to see the demise of this product and it is unfortunate that W & N is still offering their “cleaning” solution. Matthew, it is interesting what you quote about the ingredients in the W & N product. I remember their Winsor & Newton Artists’ Picture Cleaner was an emulsion of ammonia in copaiba balsam. The following line from an advert of the product on Amazon suggests that it remains so: “A natural resin/oil emulsion containing ammonia designed for cleaning varnished paintings” Perhaps you are thinking of another nostrum sold by them or another source.
More to the point, one should never use these “one size fits all” nostrums to clean any painted work that you do not want to damage. These may work perfectly fine for a few works but be disastrous for others that appear to be identical in materials and condition. The protocol used for the cleaning of artworks is, by necessity, specific to the work at hand.

The knowledge and experience required to develop such protocol is just not possible for the nonprofessional. Many will find this pretentious, but it is in no way meant to be. We would not expect a layman to be competent in dentistry or any other highly skilled field, but for some reason people believe that restoration can be picked up as a hobby. Certainly this is true, but only to the detriment of the artwork as we so clearly and often see.
There can be no generally accepted cleaning solution or treatment. The artworks themselves are unique even if the same starting materials had been used due to the vagaries in technique and the fact that each work lives in a different environment. I have seen a pair of pendant paintings created by the same artist using the same paint and executed at the same time. The one hung on an interior wall was in good condition and was relatively easy to treat, while the work hung on the outside wall (not the outside of the house) was in poor condition and required very different techniques to conserve. There are works executed in oil that cannot be cleaned by any traditional methods due to the paint being soluble in the solvents that were capable of reducing the varnish. Some oil paintings are even soluble in water. Even if one is able to successfully remove a degraded varnish coating, it is very east to desiccate the paint film that will no longer saturate when a new varnish is applied.  The ammonia mentioned as an ingredient in the W & N product is notorious for this, especially when used by the unskilled. It is also very easy to leach out components of the oil paint and redeposit components of the dissolved varnish into these voids leaving a paint film that will be far more sensitive/soluble the next time it requires cleaning.
Please do not use products like these and please do not attempt to remove varnish or grime by yourself unless you have substantial training in conservation. By substantial, I mean a master’s degree in painting conservation followed by at least three years of internships/fellowships in a museum/conservation studio supervised by establish conservators. I know statements like this annoy some but they would be less annoyed if they saw all of the completely ruined works that we encounter weekly/monthly.

​Brian, it may be that this is still ammonia-based, but the SDS lists pine oil and D-Limonene, which I remember were a reason for some artists to avoid them as potential skin and respiratory sensitizers. In fact, that potential is disclosed on the SDS.  This is the correct one, yes?  http://www.winsornewton.com/assets/HealthandSafetyDataSheets/OIL%20COLOUR/Solvents/Artists%20Picture%20Cleaner/04412238.pdf

Matthew, those are also probably components of the emulsion. It is funny how MSDS sheets have worked. The ammonia component may be small enough as to not have to be listed when in actual practice it is providing a large part of the muscle.  

​Ah, that makes sense. Thanks for the clarification!