Sulphur Cast

[slokind]

What is a sulphur cast?  How was it done?  What were its advantages for study?
I keep running across the term in old articles, but I can't find it in Numiswiki.
Pat L.

[curtislclay]

Plaster casts are of the obv. or rev. only.  So you need two of them for each coin, which actually has great advantages for study: there is no hidden side needing to be turned over, you can write information about source, weight, axis, die number on the blank back, and you can separate the obv. from the rev. in order to do your die comparisons with like designs, the obverses on the one hand and the reverse types on the other.

All sulphur casts that I have ever seen have both sides on the same cast, just like the original coin.  I believe Mionnet's sulphur casts were all black, but Captain Smyth's are green, red, yellow, the better to imitate the original patinas on his Roman sestertii.  So a collector might prefer sulphur casts, they're much more like the original coins. 

For study purposes sulphur casts are awkward, again just like the original coins.  The student will want to make plaster casts or photographs of the originals, in order to be able to conveniently study them, and for the same reason he will want to make plaster casts or photographs of any sulphur casts he comes across!

I don't know how sulphur casts are manufactured.  Mionnet's original molds turned up some thirty years ago and were supposed to be published by a team including Maria Radnoti-Alföldi.  If that book ever appears, hopefully it will explain to us how sulphur casts were made.

[aj]

Sulphur casts are used to measure or reproduce very accuraetly the dimensions of what has been cast. Molton sulphur mixed according to a composition called the Baker Mixture does not expand or contract when it cools so you have an absolutely accurate cast as to size.

[moonmoth]

There are a few quotes and definitions on the web.

Wictionary:

sulfur cast (plural sulfur casts)

   1. a cast made by pouring prill sulfur into a depression; used forensically to take casts of prints in snow



Gunsmithing: Manual of Firearms Design, Construction, Alteration ... - Google Books Result
by Roy F. Dunlap - 1963 - Crafts & Hobbies - 742 pages

"The sulphur cast is still the standby for chamber measurement as melted sulphur, poured into a chamber, will cool without enough shrinkage to worry about."



Here's a page which looks at footwear casts in snow:

http://www.rcmp-grc.gc.ca/firs-srij/bulletins/cs-mn-eng.htm

With a relevant quote:

"The Prill Sulphur technique produced good results which captured the crisp edges and fine detail of the original impression. This technique is probably the least expensive since prill sulphur can usually be obtained at no cost other than shipping. Remember the proper temperature of the sulphur prior to the pouring the cast is the real secret to success with this method."


This method also appears to have been used to take copies of some objects of art.

You can get more search results using the American spelling, sulfur.  These snippets at least explain why elemental sulphur was used, if not the detailed method of casting coin impressions.



(Added): Here's a link which describes the casting process for footwear in more detail.

http://www.csigizmos.com/products/toolimpressionmaterial/sulfur.html


Bill

[aj]

Well yes my information is from gunsmithing and collecting old weapons to check calibre.

Here are the proportions of the mixture used.

Sulphur 2 ounces.
Powdered lamp black 3 grains
Alcohol dissolved gun camphor 2 or 3 drops.

This is the classic mixture to be melted and poured.

I have not got a copy of Dunlap but it may be on line. I use the mixture my grandfather advised on when I started helping him as a boy in the late 1950's.

[ChaOus]

              Is this Sulphur Cast is the same as Sulfur Cast? I am really confused about this two. Can you clear this thing to me.?

_________________
private labeling

[moonmoth]

It's sulphur in Britain and sulfur in the USA - the same thing.