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ID query - Vasart ?

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Derek:
Hi Kev

Any more thoughts on the cause of the "rusting" as I have also seen this in one example??
Could it be contamination on the grinding wheel??

Best regards

Derek

Sach:

--- Quote from: Derek on December 05, 2008, 08:17:43 AM ---Hi Kev

Any more thoughts on the cause of the "rusting" as I have also seen this in one example??
Could it be contamination on the grinding wheel??

Best regards

Derek

--- End quote ---

More likely it is a tool mark.  The "pontil" or "punte mark" on many weights is not a true pontil at all. It is actually a neck.  A pontil is created when a bit of hot glass on the end of a punte rod is touched to the base of a piece to form a temporary bond.  This allows the piece to be broken of at the other end and worked in in the glory hole as when the glassblower wants to open the neck of a vessel.  A neck is created using the jacks to compress the hot glass and form a narrowing in the hot glass.  The neck is the point at which the glass is broken off when a punte is attached.  In hot worked paperweights the piece is never reversed.  The glass is necked down and broken off for placement directly into the annealer without transferring to a punte.  If the glass is a bit too cold when the neck is created, or if the worker hold the jacks in place too long or with too much pressure the tool can leave a mark on the glass.  This is essentially a small bit if the metal from the tool that is scraped off the tool and remains bonded to the surface of the glass.

aa:

--- Quote from: Sach on December 05, 2008, 12:29:13 PM ---In hot worked paperweights the piece is never reversed. 

--- End quote ---

I would suggest "not usually", rather than never!
It is not uncommon with more complex weights to reverse, sometimes more than once! ;)

KevinH:
Yes, my understanding now is that the rusting is likely caused during the "necking" or "cutting in" process that Sach has described. There was another example discussed in a message in Dec 2007 - and that amount of rust is quite typical on many of the old "Dump" weights.

My use of the term "pontil mark" is simply to maintain a usage of wording that has become common amongst collectors in most English speaking countries. For correctness, in many (most?) cases of paperweight manufacture, perhaps we ought to speak of "finishing" - which also includes final polishing. "Pontil mark" (or "pontil area" as is sometimes used) is, however, the most widely understood term for the various lumps, bumps, ridges, ground bits, etc. remaining on the central part of a paperweight base.

Sach:

Agreed and understood with regard to both comments!  I should know better than to use the terms "never" or "always".

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