Painting damaged by fire

During a fire (with no use of water), two things happen:

    1.  The soot covers the painting like dust and can normally be
        removed.

    2.  Under the effect of heat, soot binds herself to the paint
        layer and black spots appear, which are very difficult to
        remove, especially if the painting hasn't been varnished.

I know about the possibility of putting the painting under a strong
source of light to remove the spots but I'm interested in knowing
what's the effect of the soot remaining on the canvas. In case the
canvas stays on its original stretcher, even if you clean very well,
rests of soot can stay between stretcher and canvas. Are there any
analysis about soot, its effect, its composition, and the ways to
remove it ? And about the black spots, can they become irreversible
if they can't be removed quickly?

Catherine Reymond,
graduated restorer and historian of art



                                  ***
                  Conservation DistList Instance 13:50
                 Distributed: Wednesday, April 5, 2000
                       Message Id: cdl-13-50-019
                                  ***