PurplePerson1
SGF, Supreme Grumble Framer
We are always talking about acid damaging art. Alkalinity would be just as bad? What does it do to art as opposed to acid? Could we discuss this? Obviously, we want PH neutral.
alkalinity
- Thread starter PurplePerson1
- Start date
preservator
SGF, Supreme Grumble Framer
Unfortunately, ours is an acidic atmosphere and
neutral materials such as papers begin to become
acidic as soon as they are made. As Ellen Collins
likes to say, "Ammonia is acid-free." but it is
obviously too alkaline. If there is an alkaline
reserve of calcium carbonate in a paper or board
and the pH is between 7-8.5; the paper should last
longer and nothing alkaline should come out of the
board or paper. Some tissues are actually cigarette paper and they have such a heavy chalk
loading that the chalk can come off the surface of
the paper. That paper or materials with pH of 9-10 or above might be a little too alkaline.
Hugh
neutral materials such as papers begin to become
acidic as soon as they are made. As Ellen Collins
likes to say, "Ammonia is acid-free." but it is
obviously too alkaline. If there is an alkaline
reserve of calcium carbonate in a paper or board
and the pH is between 7-8.5; the paper should last
longer and nothing alkaline should come out of the
board or paper. Some tissues are actually cigarette paper and they have such a heavy chalk
loading that the chalk can come off the surface of
the paper. That paper or materials with pH of 9-10 or above might be a little too alkaline.
Hugh
Hugh I am way out of my league here but i think what Susan is asking about is something like the damage that can occur to certain photographs( i belive they have Album ,egg, emulsion coatings) from those Calcium Corbomate loaded mats .What i mean is i think she wants to know particulars.
BUDDY
BUDDY
I believe that the notion of calcium carbonate buffered boards causing damage to photographs has fallen out-of-favor in recent years.
In other words, it is probably not beneficial to use unbuffered rag to mat photos.
(I don't think that's what Susan was asking, but I think that's what Buddy was referring to.)
In other words, it is probably not beneficial to use unbuffered rag to mat photos.
(I don't think that's what Susan was asking, but I think that's what Buddy was referring to.)
PurplePerson1
SGF, Supreme Grumble Framer
Actually, I am leaning more toward Hugh's answer. The other part is, if something is mounted on a surface too alkaline, what happens to the art, whether it is photographs, prints, etc.
Chalk is alkaline, what happens over time when the artist puts it on an acid paper. Would it balance out depending on the PH levels of each? It would seem, that since we live in a more acid environment that it would not balance out, but should be mounted only acid free.
I think my questions are more theoretical. I am curious.
[ 06-03-2003, 01:02 PM: Message edited by: Susan N ]
Chalk is alkaline, what happens over time when the artist puts it on an acid paper. Would it balance out depending on the PH levels of each? It would seem, that since we live in a more acid environment that it would not balance out, but should be mounted only acid free.
I think my questions are more theoretical. I am curious.
[ 06-03-2003, 01:02 PM: Message edited by: Susan N ]
jvandy57
SGF, Supreme Grumble Framer
Susan,
When I teach pH I always say that the further away from a pH of 7 you go the more corrosive a material becomes.
Acid<-------7------->base
Corr corr
Therefore an extremely alkaline material can cause as much corrosion as an acidic one. One drain cleaner (Drano) is Sodium Hydroxide (NaOH) and chews up organic materials though slowly. Another drain cleaner (Liquid Fire) is Sulphuric Acid (H2SO4) can really clean drains quickly. Can also chew up and spit out your pipes.
does this help explain anything?
When I teach pH I always say that the further away from a pH of 7 you go the more corrosive a material becomes.
Acid<-------7------->base
Corr corr
Therefore an extremely alkaline material can cause as much corrosion as an acidic one. One drain cleaner (Drano) is Sodium Hydroxide (NaOH) and chews up organic materials though slowly. Another drain cleaner (Liquid Fire) is Sulphuric Acid (H2SO4) can really clean drains quickly. Can also chew up and spit out your pipes.
does this help explain anything?
PurplePerson1
SGF, Supreme Grumble Framer
I am sorry to relate this issue to dairy goats, but when I was milking goats every day, the jars I put the milk in would build up a dull surface. We called it milk stone and no amount of cleaning took it off. It appeared that the surface had been permanently marred, not that a substance was on it. I would pour in a little Clorox and the milk stone went away, instantly. The jar became shiny and new.
We have gotten some old glass in from what we call plague frames and it has that marred looking surface. No amount of cleaning gets it off. I remembered milk stone on my milk jars, so I took the glass to the bathroom and rinsed it in Clorox. The glass was clean instantly. Of course, I rinsed and rinsed and rinsed.
I am sure this has to do with the alkaline and acid problem. Since Clorox is alkaline, the film on the glass must have been acid, right? Therefore, the framing package was acid and if we do not use acid free products, in 50 years our glass will look like that.
I will remember that the closer to 7 that we can be, is the best we can do.
[ 06-03-2003, 02:20 PM: Message edited by: Susan N ]
We have gotten some old glass in from what we call plague frames and it has that marred looking surface. No amount of cleaning gets it off. I remembered milk stone on my milk jars, so I took the glass to the bathroom and rinsed it in Clorox. The glass was clean instantly. Of course, I rinsed and rinsed and rinsed.
I am sure this has to do with the alkaline and acid problem. Since Clorox is alkaline, the film on the glass must have been acid, right? Therefore, the framing package was acid and if we do not use acid free products, in 50 years our glass will look like that.
I will remember that the closer to 7 that we can be, is the best we can do.
[ 06-03-2003, 02:20 PM: Message edited by: Susan N ]
preservator
SGF, Supreme Grumble Framer
Yes to all. As Buddy mentioned, there was some
work done in the 1970's the suggested that the
protein in photos could suffer in proximity to
alkaline material. As Ron said, this has been
reconsidered and is no longer held to be a pressing issue. Certain exotic processes such as
cyanotype need acidic conditions and should not
be contact with alkaline board, but they are not
often encountered. If one runs into such an item,
a sheet of unbuffered tissue between the mat and
the photo should suffice, since unlike acid,
alkaline substances such as chalk do not seem to
form aerosols, which could penetrate the tissue.
Highly reactive metals such as lead, silver and
copper might also benefit from the use of an inter-layer of unbuffered tissue, but there is not
much reported data that shows any harm that has
come to works of art or artifacts from proximity
to boards that have an alkaline reserve.
Hugh
work done in the 1970's the suggested that the
protein in photos could suffer in proximity to
alkaline material. As Ron said, this has been
reconsidered and is no longer held to be a pressing issue. Certain exotic processes such as
cyanotype need acidic conditions and should not
be contact with alkaline board, but they are not
often encountered. If one runs into such an item,
a sheet of unbuffered tissue between the mat and
the photo should suffice, since unlike acid,
alkaline substances such as chalk do not seem to
form aerosols, which could penetrate the tissue.
Highly reactive metals such as lead, silver and
copper might also benefit from the use of an inter-layer of unbuffered tissue, but there is not
much reported data that shows any harm that has
come to works of art or artifacts from proximity
to boards that have an alkaline reserve.
Hugh
Wouldn't it be safe to say that any extremes, whether we're talking about pH, temperature or humidity, are likely to be harmful to art? It's just that we're far more likely to encounter acidic papers and boards, because of the nature of the manufacturing process, than we are to find one that's too alkaline.
preservator
SGF, Supreme Grumble Framer
Yes, moderation is the soul of preservation, or words to that effect.
Hugh
Hugh