Good questions.
One effective method for sulphurized stamps is to place them above the hydrogen peroxide fluid. I used a flat dish of peroxide and add a small second ‘platform’ which the stamp lays upon above the fluid. Then I seal the entire container so the out-gassing of the peroxide will change the stamp color back to its original state. Note that this normally takes a day or two, just leave everything in place for as long as it takes.
Don
Thanks Don. What about foxing on chalky paper? What method could be used effectively?
I guess once a used stamp has been soaked off then it becomes more challenging. The watermark fluid is just more of the same?
What method would ammonia be applied for chalky stamps? A sweat box style?
Ammonia is actually gas infused in water. So, if you put the stamp in the solution, most of it will be water getting onto the stamp. In my earlier experiments with ammonia, the ammonia in the solution did a very good to decent job of cleaning the foxing. However, the water removed gum on gummed stamps and it softened/dissolved ink on stamps that were printed with aniline/water soluble inks.
I did not use a sweat box, but that would probably be the best way to try with chalky paper. I agree that the water peroxide solution will work in a sweat box to remove sulphurization. Ammonia, I'm not so sure. It probably would work, but may take longer since with foxing one is looking at a fungal problem in the paper fibers, and not a chemical reaction with the ink. Also, it may not remove the foxing as well as an ammonia bath would. I don't think anyone reported on using ammonia in a sweat box to remove foxing.
In reviewing the explanation on Chalky paper at the beginning of the Scott Catalogue, it states "the designs of stamps printed on chalky paper are imprinted on what is often a water-soluble coating ... Do not soak these stamps in any fluid."
Generally speaking, we soak stamps on paper which removes the stamp from the paper. When we have a stamp made on chalky paper (if we have the ability and knowledge to identify this paper type BEFORE we try to separate it), we use the reverse method of removing the paper from the stamp (as opposed to the stamp from the paper).
My question is related to the "do not soak these stamps in any fluid." We've had discussions on foxing and sulphurized stamps as well as watermarks. In order to approach any of these three issues, fluids must be applied to the stamp (appropriate fluid per issue). As Scott has stated not to soak chalky paper in fluid, how is it possible to perform any of the above on this variety of paper without causing damage to the pigmentation (which is obviously the reason why it states to separate the paper from the stamp as opposed to soaking)?
re: Question re: Chalky Paper and Fluid
Good questions.
One effective method for sulphurized stamps is to place them above the hydrogen peroxide fluid. I used a flat dish of peroxide and add a small second ‘platform’ which the stamp lays upon above the fluid. Then I seal the entire container so the out-gassing of the peroxide will change the stamp color back to its original state. Note that this normally takes a day or two, just leave everything in place for as long as it takes.
Don
re: Question re: Chalky Paper and Fluid
Thanks Don. What about foxing on chalky paper? What method could be used effectively?
re: Question re: Chalky Paper and Fluid
I guess once a used stamp has been soaked off then it becomes more challenging. The watermark fluid is just more of the same?
re: Question re: Chalky Paper and Fluid
What method would ammonia be applied for chalky stamps? A sweat box style?
re: Question re: Chalky Paper and Fluid
Ammonia is actually gas infused in water. So, if you put the stamp in the solution, most of it will be water getting onto the stamp. In my earlier experiments with ammonia, the ammonia in the solution did a very good to decent job of cleaning the foxing. However, the water removed gum on gummed stamps and it softened/dissolved ink on stamps that were printed with aniline/water soluble inks.
I did not use a sweat box, but that would probably be the best way to try with chalky paper. I agree that the water peroxide solution will work in a sweat box to remove sulphurization. Ammonia, I'm not so sure. It probably would work, but may take longer since with foxing one is looking at a fungal problem in the paper fibers, and not a chemical reaction with the ink. Also, it may not remove the foxing as well as an ammonia bath would. I don't think anyone reported on using ammonia in a sweat box to remove foxing.