Rust on notes

[Weg]

I've seen notes with very minor rust stains to notes with holes in them from rust. I'm wondering what the process is to where rust makes a hole in a note.

 

Lets say I have a note with a dark area about 1/4 inch diameter and in the center there is a hole about the size of a pinhead. I'm not sure how rust eats paper so is there any chance the hole will become larger in time?

 

If rust does "eat" paper, I'm wondering if for this example if the pinhead size hole in the 1/4 inch dark rust stain would in time become a 1/4 inch hole. I imagine if the note was left in a humid area whatever process is going on that made the hole that it could continue.

[Guest Dana G]

Hi Weg,

 

It depends on the size and severity of the rust along with any other contributing factors that may aid or inhibit further growth. It is definitely possible that the hole could become larger, but it is hard to say with any certainty if the rust on this note will continue to react.

 

 

 

 

[Weg]

Hello Dana,

 

In about a month I will be sending a group of notes for grading and one note in this group has this problem. What I'm attempting to figure out is if I should or need to find a way to neutralize the acid in the rust spot before the note is encapsulated. As it is today there is a hole which will always be there and I'm fine with that. What I'm concerned with is the hole getting larger.

 

This is a conservation concern. I understand some knowledge in this area could be used for doctoring which is not my intent; the hole will always be there on this note. Please feel free to send a private message if there is any information that could help but be abused by doctors in the public.

[BC1]

When the metallic object was in contact with the paper of the note, oxidation occurred and the residue transferred to and became entangled between very tiny spaces that are present in the fibers of the natural paper. The rust particles are not really bonded to the paper fibers, but rather trapped in those tiny spaces. Over time the area becomes saturated with the oxidizing iron particles and a stain appears.

 

Old and historic paper documents which were written on with iron gall inks, suffer greatly from similar issues that is akin to rust stains on paper banknotes. Because those materials also contained ferrous iron ions in their composition, that are reactive with atmospheric oxygen and this highly acidic substance is damaging to paper over time. This includes even the low or neutral pH natural fiber linen "rag" papers that banknotes are printed on.

 

Over time, areas which display concentrations of rust can worsen because of active oxidation occurring to the residual material on the paper, even after the offending metal object is removed. Ultimately, holes may be eaten through the surface of the paper. Tempering the note with special conservation papers embedded with calcium carbonate can help, but they need to be changed regularly as they work to absorb acids away from the problem areas.

 

Storage of such notes in controlled environments with stable humidity and an atmosphere itself that is non-acidic are crucial to limiting long term effects where damage has already taken root. Similarly, such storage discipline is a prudent bit of advice for storing any collection of paper documents, be they bank note or other collectibles.

 

If considering a note which displays rust stains for one's collection, the prescience of rust should be a reminder to the long term preservation challenges one faces for obtaining such a note. Paper is an incredibly fragile yet dynamically resilient material. While sturdy for use in commerce, time has its effects to weaken and decay this material. Elements in the atmosphere and any invasive material from handling a note, breathing on it or exposure from microorganism such as mildew or fungal spores carried in the air, must be diligently considered when storing paper objects long term.