Drying medium?

[Richard Bingham]

Thoughts I have pertain only to alkyd materials, not who uses them. I have known a number of artists with national reputations whose work is superlative, whose materials choices and application methods I sometimes find worrisome from my own experience. It's tough to abuse either to the point of failure in a very short time, however, and after all, it's what the work looks like that interests the patron, not how, or with what.

Alkyd resin is a synthetic material derived from the combination of an acid and alcohol. The initial nomenclature reflected this, "al-cid" and later became "alkyd". The discovery was first applied to automotive utility coatings in the mid-1930's (DuPont's DuLux). Fast drying, tougher than nitrocellulose lacquer used well into the 1950's, it remains a staple for commercial and utility applications.

Used to advantage in oil painting where the work is completed wet-in-wet in one sitting, it should pose no particular problems. An alkyd medium mixed in colors, then subsequently over-painted stands a possibility of de-laminating. The addition of drying oils to alkyd vehicles makes fresh applications painted over dry films especially prone to separation unless the dry layer is abraded to provide a mechanical "key" for bonding (i.e., "sand between coats"). This is because surface-dry layers of alkyd paints do not fuse with fresh paint through solvent transfers and resulting chemical bonds as natural resins permit.

Again, why "mess" with a system that (with all its possibilities and complexities) has worked for 500 years? It will require another 100 years to find out if alkyds are better or worse than anything that has been used in previous centuries.

[Michele Rushworth]

Everything I've read (both here and elsewhere) makes me think I'm still better off just continuing to use paint straight from the tube, as I have been for the past several years.

A different nationally known artist told me he accellerates the drying of his paintings by using a space heater and a fan. Seems safer than a lot of the different mediums and additives that are out there!

[Richard Bingham]

Originally Posted by Michele Rushworth

. . . think I'm still better off just continuing to use paint straight from the tube . . . accelerate drying . . . by using a space heater and a fan. Seems safer than a lot of the different mediums and additives that are out there!

So long as your paint is high quality, there's no question that's a sound approach. Paint definitely dries faster when it's warm and dry, and air movement speeds up the process, so controlling the studio environment to hasten drying time is certainly an option.

The biggest problem for those who buy mediums is assuring the quality and contents of "store-bought" mediums. (e.g. the "imitation" copal medium mentioned above) As far as "safety", we tend to do a lot of hand-wringing over "archival permanence", but the truth is that it's really, really hard to force painting materials and mediums into failure. Even the worst materials and practices generally have to age 50 to 80 years to become visibly obvious.

Speaking of copal, the term is as non-specific as saying "use apples". There are a number of resins collected commercially from Mexico, Central America, Africa and Indonesia all identified as "copal" although different species have quite different characteristics. Congo copal was the standard for clarity and hardness in the days when natural resins were used to manufacture the bulk of varnishes used for home and commercial finishes. Owing to the on-going political strife in that region of Africa, it hasn't been commercially available for many years.