Painting Over Dried Painting
 

Hey, what would you suggest for painting over a painting that has dried for 8 months to a year or more? I have some Old Holland retouch and can also make some "real copal" varnish with turps or spike. Is abrasion necessary and is there a widow of opportunity for painting over the retouch?

Oh, and there is no medium used in th existing paint layer, if that matters... Does it?

Many questions... Thanks for your time.

Peace,

I did this a couple of years ago and I had no problems so far. You'll have to oil it with 1/2 part of lineseed oil and 1/2 of mineral spirits. Use a rag, you'll need just a thin layer, not too dry nor too wet.

:thumbsup: Well... That's simple enough. I thought I would need to use retouch and/or abrade the surface.

Thanks for sharing.

Peace Out,

my oiling out disaster
 

I used the raw linseed oil/solvent to oil out a dried (only a few weeks) painting and somehow got a completely unworkable glassy surface which I then had to sand down and repaint the whole face. I went on to research further and found websites dedicated to the technical side of painting. (http://www.amien.org/) (http://rourkevisualart.com/wordpress/) (http://www.tadspurgeon.com) which pretty much say of oiling out, "don't do it." Mostly, the conclusion seems to be that it's the rawness of the oil rather than the type of oil. Raw oil isn't so good. Tad Spurgeon's site is a long, hard read but worthwhile. The formula I'm using now for retouching is Oil of Spike Lavender (1 part) and my own home-produced walnut sun oil (1 part.) Robert Doak in New York sells sun oil if you don't want to make your own.

I'm certainly no expert, but any of the guys with those websites will talk to you about these issues.

All of which points to the dismal state in which we find ourselves in the 21st century, with such uncertainties in obtaining a working knowledge of oil paint, its nature, and the relatively simple materials, principles and processes that comprise sound craftsmanship in applying it. Spurgeon's site is a good source of information, thank you for noting additional sources.

Back to the initial question, in general, a painting 8 to 12 months old may be considered to be "thoroughly dry", i.e., all free solvents will have evaporated, and all paint films are firmly "set" into irreversable polymers. Of course, variables obtain, such as the thickness of the paint, the materials used, and ambient conditions.

To continue painting on an aged surface, most painters will require to properly assess the true color and value of dry, sunk-in passages. "Fat" areas that present a slick, shiny, or even tactilely oily surface will be problematic for adhesion of subsequent applications. Both problems are best solved with a sparing application of retouch varnish.

Damar will remain soluble in the presence of solvents used in overpainting, copal will not. Either may be more or less agreeable depending on one's method of working and the end in view. In short, there's nothing at all wrong with going back into a painting that has been "stalled" for months . . . or even years. In fact, it is better practise to paint over a thorougly dry surface than it is to begin painting over surface-dry underlayers, where overpainting can interfere with proper curing of the first layers of paint.

"Oiling out" is a process with limited application, and even less appeal, and no one really knows how to do it, or when to apply it. In the main, linseed oil (and other drying oils) have been considered "varnishes" from time immemorial. When a completed, thoroughly dry painting presents dry, sunk-in passages, no more than a drop or two of linseed oil, applied to those surfaces, and rubbed in with the heel of one's palm with enough vigor to generate warmth from friction will correct the problem. It is no less than miraculous how far a drop of oil goes in this process. The result is that the lean passages are thus "varnished". Applying a 50/50 mix of oil and solvent with a brush or daub is a different thing entirely, and invariably deposits enough oil to be deleterious to the painting as it ages.

Since the question is actually how best to unify the surface of a completed, thoroughly dry picture, application of an appropriate final varnish is the best solution, since it's really quite doubtful those "sunk in" passages actually display the results of paint so underbound that an additional application of free oil is called for.

Good stuff... Thanks! I'm thinking spraying a thin copal turps mix. Is there a window of time you would want to paint on top of the retouch varnish? I would like to varnish the whole piece at once and proceed in painting it in sections. My goal is to finish it early next month.

Happy Thanksgiving...mmmmmmm...Turkey :D .

Thank You, Peace,

You can paint on the retouch varnish as soon as it's dry to the touch. Retouch varnishes should be reduced to the point of depositing as little resin as possible to be effective, and applied as sparingly as possible. As to the "window" an ideal application will sometimes allow a dead passage to "sink" again if left too long. Spot applications are better than varnishing the whole piece, unless the painting is small, and you intend to work "all over" rather than in passages.

Thank You, Richard.

Peace

My pleasure, David.

Everyone, Happy Thanksgiving!!

Dear Melanie, I'm sorry about your experience. Mine was fine.

And David,

Do not use Damar, it yellows a lot with time.

Claudemir, do not use oil paint . . . for the same reason.

Lol...

Claudemir, thanks for smiling. I meant to be neither flippant nor combative, and didn't have a lot of time yesterday.

On the subject of damar, I'd be obliged to know your specific concerns for its yellowing, and experiences with that. I'm guessing that the climate where you live is tropical, and perhaps quite humid (?) which definitely could be a source of observations very different from my own.

It's my belief that a lot of what passses into the lore of painting materials and methods can be greatly influenced by climatic and ambient conditions that are never noted, as if we all lived and worked under the same conditions.

It's almost always a mistake to make unqualified statements about materials and their properties. Especially with natural resins, oils and solvents, their source of origin, quality, and methods of preparation are all variables that obtain even before one opens the question of the wide variety of possible working applications.

Why I feel that high quality damar (Singapore, if you can get it) cut with pure spirits of gum turpentine (the real thing, not the creosote-reeking stumps 'n' limbs juice one commonly finds these days) is not particularly a problem for causing yellowing is that through the course of 35 years as a sign maker and illustrator, I have used damar varnish to mock such glass crafting techniques as glue-chipping and etching in producing gold leaf signage on storefront windows. Damar applies water-clear, and has generally remained so in a number of projects and inscriptions now over twenty years old.

Also, I retain a number of my father's paintings, some of which are now nearing 70 years old. Having learned painting methods at his elbow, I can attest that damar was used to some extent in all of them both as a retouching varnish, and as a final varnish. None are yellowing, changing or darkening to any perceptible extent.

That said, all were painted, and have remained, in this high altitude, low relative humidity, temperate climate, and have been well-housed and cared for.

Forgive me for going into such detail, but if one is either to dismiss or defend a particular material, I feel obligated to offer reasonable substantiation for the claim.

Happy Thanksgiving Day to one and all!

Thanks Richard, and sorry for taking so long to answer.

I think the weather might be the problem. Some 20 year old paintings were really yellow because of he varnish.

I think I should move to your neighborhood and then I might enjoy the same material you guys use.