Oil cracked over acrylic

Arizona

More or less twenty years ago I started a large acrylic on canvas painting . To enjoy the slow drying time of oils,I decided to paint the sky in thin layers of oil. Flaking paint was the result. Now using Easy-off to remove the oil paint. Question....when complete with the oil paint removal,  do you recommend painting the sky in acrylic or Alkyard? Also do I need a barrier coat before application of next paint?

VickyCurtin

Just out of interest, how long did it take before the oil paint started flaking? 

Arizona

Vicky it took about 10 years....didn't crack at all just started to flake and even fall off of canvas. Could have been my doing as it was my first oil painting and one over an acrylic base at that. The acrylic coat is spotless.

Summer

Arizona said: I decided to paint the sky in thin layers of oil.

do you recommend painting the sky in acrylic or Alkyard?

Also do I need a barrier coat before application of next paint?

First, It seems to me that when you painted thin layers of oil for the sky, the fat over lean rule was absent--if in fact you painted layers and they were all thin.  This may be the entire problem.  There is no reason to paint the sky with acrylic or alkyd paints if what you want is to paint it in oil.  I think that If the acrylic layer is stable after you have " cleaned" the painting, just begin painting the sky again with oil paint but observe the fat over lean rule with each subsequent layer.  If the acrylic layer is stable, you don't need a barrier coat between the acrylic and the new oil you plan to apply because the surface you are painting on is acrylic and not oil.  If the acrylic surface had been oil, then, yes, you would have to prepare the surface by oiling out first.  Hope this helps.  But honestly, because of the age of the painting, I think what you are doing is more of a restoration project in which case I would get the advice of a professional restorer.  I hope you will let us know how this turns out, whatever you decide to do.  Summer