Week Four: Oil Paint Removal

Hello. Welcome back to the weekly report on the conservation treatment on a Bishop Saint with Donor. Last week I continued cleaning the pink areas of the painting corresponding to the throne of the Bishop. Many of these areas have many old repaints made with oil paint that cover original paint. Since they are insoluble to solvents, a different approach to remove them had to be used. "Solvent gels" were tested and since they proved to be effective, they were used. A "solvent gel" is a solvent mixed with a gel that has a thick consistency. By "gelling" the solvent, this can be put in contact with the repaint for a longer period of time.
	The gel is applied only on the areas of repaint and let to "act" for the needed period of time (2 minutes in this case). Then the gel with the softened overpaint is removed and the surface is cleaned with the solvent.
Of course, prior to using this technique, small tests on specific areas of overpaint have to be done. Since every overpaint is different, the time and type of solvent gel used to remove it is going to change. This technique can not always be used. If the paint layer is also sensitive to the action of the solvent gel, the method has to be abandoned. In this case, the paint layer was tested and it was safe to use this approach. This process is very time consuming and since there is a lot of overpaint to be removed, it will take me a lot of time to finish the cleaning stage. Next week I will look at the figure of the donor. See you then.
	Before and after cleaning. Note how much the oil overpaint has discolored (on the left). By removing it, the original paint is uncovered.

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