Conservation and Restoration

[Rick J]

I am interested in any scientific data / information on the "degradation" of the linen and cotton canvases from exposure to linseed and similar oils. I am especially interested in studies that shed some light on the mechanism of the so-called degradation.

The key work is "scientific". I realize there is a lot folklore on this subject, but I'm looking for (published) studies that have approaced this topic on a scientific basis.

I also be interested in any references for restoration / conservation of "damaged" canvases.

Amy help would be greatly appreciated.

Thanks,

Rick January

[markg]

Hi Rick:

A chemist at the Smithsonian Center for Materials Research and Education has about 30 years worth of research on the degradation of binders -- specifically oils, I think, and he's working on a book on the subject to be published next year. The publisher is a specialty conservation house, so you are unlikely to find the book at the Atlanta public library.

I'm going to send him your question and see what he says. He is also getting some documents ready to post in the BINDERS forum: they contain plenty of science.

There is also plenty of science in the conservation community, too -- it just doesn't get published where we users, or you manufacturers, can readily see it. "What we have heah is a failure to commun'cate" (Strother Martin, "Cool Hand Luke"). So I'll send your query to a couple of conservators and see what THEY say. They may also provide some conservation references for you.

Meanwhile, you could go to Conservation Online, the AIC, and CAMEO (see the LINKS page) and grub around in those sites for references and scientific information. The AIC might send your query to a bibliographic site. In CAMEO you can ask questions about definitions and other information of an encyclopedic nature.

[prostovsky]

Dear AMIEN,

A painting of mine was caught in a flood recently (a water pipe burst) and though the face of the painting is undamaged, there was some staining on the back and sides of the painting when the water had dried. This area was exposed linen that was not covered with PVA size or gesso. The stains are yellowish or rust colored. I am wondering if there is some method of washing or sponging these out without compromising the painting. The only thing I can think of is rewetting these areas and trying to suck up the stains with a dry sponge. Many thanks in advance.

[AMIEN]

Dear AMIEN,

A painting of mine was caught in a flood recently (a water pipe burst) and though the face of the painting is undamaged, there was some staining on the back and sides of the painting when the water had dried. This area was exposed linen that was not covered with PVA size or gesso. The stains are yellowish or rust colored. I am wondering if there is some method of washing or sponging these out without compromising the painting. The only thing I can think of is rewetting these areas and trying to suck up the stains with a dry sponge. Many thanks in advance.

prostovsky,

We are not conservators, so we will refer this question for comment to one who is.

However, we can say that sometimes the best course of action is to leave well enough alone. If there is no damage to the painting and the picture is completely dry, why do anything?

More later, we hope.

[Heather Galloway]

I would have to second the advice already given by AMIEN when it comes to removing stains from a linen canvas that has been exposed to water. The tides lines that you see on the canvas right now, appearing on the tacking margins and the reverse of the canvas, are most likely a combination of materials carried by the flood water as well as materials in the canvas that when wet can move and collect as the moisture evaporates. It is true that conservators would treat such staining, if it were appearing on the face of the painting, with the controlled application of moisture. The key word here is control and conservators have more tools and techniques available to undertake such efforts safely. To re-wet the canvas too extensively can move the staining further into the structure or move it out laterally in ever widening circles of staining each time putting the painting at further risk of damage. You could try lightly stroking a soot sponge (also sold under the promise of removing pet hair from furniture), available at many hardware stores, over the canvas to remove any loosely adhered foreign material in those tide lines to minimize their aesthetic impact but after that I would sit tight. If the staining has had no visual impact on the image of the painting at this point it is highly likely that it will never will so it is better to be thankful that no worse damage occurred. Should that stain effect your image than I would recommend contacting a conservator for more careful consideration.

Heather Galloway
Painting Conservator

[AMIEN]

I would have to second the advice already given by AMIEN when it comes to removing stains from a linen canvas that has been exposed to water. The tides lines that you see on the canvas right now, appearing on the tacking margins and the reverse of the canvas, are most likely a combination of materials carried by the flood water as well as materials in the canvas that when wet can move and collect as the moisture evaporates. It is true that conservators would treat such staining, if it were appearing on the face of the painting, with the controlled application of moisture. The key word here is control and conservators have more tools and techniques available to undertake such efforts safely. To re-wet the canvas too extensively can move the staining further into the structure or move it out laterally in ever widening circles of staining each time putting the painting at further risk of damage. You could try lightly stroking a soot sponge (also sold under the promise of removing pet hair from furniture), available at many hardware stores, over the canvas to remove any loosely adhered foreign material in those tide lines to minimize their aesthetic impact but after that I would sit tight. If the staining has had no visual impact on the image of the painting at this point it is highly likely that it will never will so it is better to be thankful that no worse damage occurred. Should that stain effect your image than I would recommend contacting a conservator for more careful consideration.

Heather Galloway
Painting Conservator

Heather Galloway,

Welcome to AMIEN and we thank you for this further information.

[prostovsky]

Thank you AMIEN and Heather. That is all very useful advice. I will try to find one of those soot sponges and see if brushing it lightly minimizes those stain lines. I agree, I should be grateful it is mostly on the back of the painting.

[AMIEN]

Thank you AMIEN and Heather. That is all very useful advice. I will try to find one of those soot sponges and see if brushing it lightly minimizes those stain lines. I agree, I should be grateful it is mostly on the back of the painting.

prostovsky,

We think you should not bother trying to get one of those sponges. But, what do you mean by " ... mostly on the back of the painting ... "?

[prostovsky]

Dear AMIEN,

Sorry for the lag in reply to this. What I mean by the back of the painting is the area where the linen is stapled to the stretcher bars. The painting in question was bought, and the collector is worried about devaluation given the staining --even if it's on the parts of the painting that the viewer can't see. She had initially shown it to a conservator who said that the stains are not removable. I was just trying to get a second opinion in case a remedy exists for such a thing. It seems so, but perhaps not worth the risks of the attempt. Thanks for your help.

[AMIEN]

Dear AMIEN,

Sorry for the lag in reply to this. What I mean by the back of the painting is the area where the linen is stapled to the stretcher bars. The painting in question was bought, and the collector is worried about devaluation given the staining --even if it's on the parts of the painting that the viewer can't see. She had initially shown it to a conservator who said that the stains are not removable. I was just trying to get a second opinion in case a remedy exists for such a thing. It seems so, but perhaps not worth the risks of the attempt. Thanks for your help.

prostovsky,

Of course neither we nor you can know for certain, but the stains would probably not affect the value of the painting one bit. We also agree that it's not worth the risks to try to remove them.