Lamp black not drying

[Susan Ballinger]

I finished a painting about a month ago and used lamp black for the background. There are still several areas on it that are not completely dry to the touch. I even mixed liquin in it. Has anyone else had similar problems? Any thoughts on it? I know different colors have different drying times, but still- a month or longer?

Susan

[Claudemir Bonfim]

Interesting... it doesn't take that long to get a black pigment dry.

Try to remove that! If you find some uneven areas after the removal, try sanding the canvas, it usually helps, then retouch it.

Good luck.

[Richard Bingham]

Interesting indeed, Susan.

What "make" is the paint ? What does the label state as to pigment contents and vehicle ?

If the paint is truly "lamp black" (i.e., a mixture of soot gleaned from the burning of lamp oil, whether a non-drying animal or vegetable oil such as olive oil or tallow, or a petroleum fuel such as kerosene) it's the nature of carbon blacks to absorb one helluva lot of oil. If the vehicle is safflower oil (nearly universal in "student grade" colors) the combination could result in a mixture that truly wouldn't dry until the cows come home.

Here's a newsflash: Liquin is a painting medium, not a siccative (drying agent). It is inadvisable to use mediums strictly as driers. Siccatives such as cobalt or manganese linoleates, or lead naphthenate may hasten the drying of paint films, but must be used sparingly and knowledgeably to avoid paint failures. Incidentally, Liquin is compounded from alkyds (synthetic resins) and petroleum distillates and its use may result in delamination if you paint in a layered technique. (e.g., underpainting, over-painting, glazing)

Mars black or ivory black are preferable choices for most palettes. Synthetic iron compounds are the pigments used for those colors nowadays (no elephants or Martians have been burned). Their chief differences being that "ivory black" should be transparent, with a decidedly cool caste, while mars black is opaque, and may run a gamut of warm to cool undertones, depending on the source. As blacks go, both are relatively much leaner than paints made with true carbon black pigments, as the oil absorptive indices of iron-based pigments is much lower than that of pigments which are essentially, different kinds of soot.

As for sound craft in "building" a painting, it is inadvisable to paint lighter values over very dark values, (especially black from the tube) and for consistent, good results, painters should have at least a nodding acquaintance with the principle of painting "fat over lean", to apply to the process of painting a picture.

Neutral mixes of dark colors are more often than not, a better choice than using blacks from the tube. Burnt umber+prussian blue yields a "black" very nearly dark enough to be indistinguishable from black straight from the tube. To boot, this mixture is lean enough to use in underpainting, and dries very rapidly !

[Susan Ballinger]

Thanks Richard. I still have a lot to learn. The paint is Georgian brand and states carbon black and vegetable black. I'm working on collecting better paint colors from professional brands, but I still have some student grades to weed out.

I have always heard that liquin is good for glazing- but is it not? And what would you recommend I use instead?

[Richard Bingham]

?? I've never heard of Georgian, but that's not too surprising.

I preach to anyone who cares to listen to avoid paints that use anything other than linseed oil as the vehicle. It's easily proven that linseed oil produces the strongest films, and of course, it's "time tested" . . . for over 500 years now. The best value for the money is to buy the very best paint. Unfortunately, some of the "big names" dominating the popular market in craft shops and discount art stores do not supply the highest quality oil paint. "Boutique" makers like Robert Doak, Cennini, Vasari, Williamsburg, Michael Harding and Old Holland, to name just a few, represent "colourmen" who truly know their craft, and are committed to high quality above corporate profit.

As it is an alkyd material, Liquin is subject to the advantages and limitations of that synthetic resin. Until well into the 20th century, all paints, whether used on automobiles, houses, ships, equipment, or any other "utility" purposes, had more in common with the paints and mediums traditionally used at the easel than is the case today. Paints, varnishes and solvents were universally based on natural, "vegetable" resins, solvents and oils. These coatings have a finite life-span exposed to full-weather and extreme conditions, so by the mid 1930's, a new generation of more durable synthetic materials were becoming available through advances in chemistry, alkyd paints among them. The resin synthesized by combining an alcohol with an acid (originally al-cid) required "hotter", more chemically active solvents derived from petroleum distillates.

The nature of alkyd coatings is to produce tough, insoluble films which require sanding between coats if multiple layers are applied, because once the surface of the paint is touch-dry, it is impervious to solvent transfer and chemical bonding between fresh coats of paint. Sanding the surface provides a mechanical "key" for a subsequent application to cling to. Otherwise, coatings can peel away from underlayers. No problem on a house or a boat, sanding the dry surface of a painting may or may not be feasible when a "work of art" is in progress.

So long as one sands between applications when Liquin or other alkyd materials have been added to the paint, all is well. Alkyds are also no problem, so long as the painting is completed in one sitting, entirely wet-in-wet.

Since the "pharmacopaeia" of oil painting materials with its wide variety of oils, resins and solvents was perfected long before the advent of petrochemicals and synthetic resins, it seems unnecessary (and counter-intuitive) to look outside the range of natural resins and oils for painting mediums. A number of superior "glazing" mediums can be easily and inexpensively made up in one's own studio with a minimal supply of traditional materials. Enter the controversy between those who (quite rightly) advocate using nothing more than high quality raw linseed oil, and those who find advantage in using mediums compounded with natural resin varnishes.

[Claudemir Bonfim]

I was sure that I would read your comments here Richard.

It is always good to read your lines.