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Prunts

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aa:
Greetings from New York, where the New York International Gift Show is almost over and the hard work of packing for shipping two hundred and fifty pieces of glass in about four hours will soon begin! (The worst bit).

The icing bag analogy is a little off the mark, but not as much as you might think.....because in the case of the original photo shown, the star shape is created before the prunt is added. There are many similarities between confectionary techniques and glass making techniques.

To create this form of prunt, you take a gather and press it in to an open (dip) mould, that looks a bit like a jelly mould. Sometimes called an optic mould. this is a multi purpose former that can be used in paperweight making to create the profile of a star or flower in cane making.

So having created a hot lump of glass with a ribbed effect, this is brought to the gaffer, who touches the body of the vessel with the hot bit and shears a piece off. The process is repeated as necessary. Reheating melts the shear mark away.

Another use for a dip mould such as this is to create the twisted stems that can be seen in one of Leni's previous posts....  sherry (?) glasses.

Leni:

--- Quote from: "aa" ---The icing bag analogy is a little off the mark, but not as much as you might think....
--- End quote ---

I knew it!  :roll: What did I say? :lol:

--- Quote ---Another use for a dip mould such as this is to create the twisted stems that can be seen in one of Leni's previous posts....  sherry (?) glasses.
--- End quote ---
 
I presume you mean these, my Murano glasses, http://tinypic.com/anbf9c.jpg  5 wine (6 originally  :cry: ) and 2 liquer (all we could carry in our hand-luggage at the time   :roll: )

Leni

Adam:
I know I am repeating myself here, but it is just possible that new members may run away with the idea that three part or four part (or two) is a fashion decision.  "part" is the same as "section".

It is an entirely practical matter.  If a vase, for example, won't come out of a two part mould without having lumps torn off it then a three part would be used.  Ditto three to four part.

The only exception which occurs to me is that some (old) mould shops might not have machine tools capable of coping with the odd angles in a three part mould.  They would then have to step straight from two to four parts.  I don't know of any actual examples of this, however.

Fundamentally, the smaller number of parts which it is possible to use the less the cost.


Adam D.

Glen:
Although this has nothing specifically to do with prunts, it has everything to do with moulds (which we have been discussing). I don't know if any of you have ever looked through my extensive feature on Rindskopf (it's on my website - click Rindskopf Revealed to see the main menu for the feature)....however, on one of the pages I have shown some original mould drawings from the Rindskopf factory. They are fascinating and informative to study.

http://www.geocities.com/carni_glass_uk_2000/RindMouldDrawings.html

Glen

PS Adam D if you happen to look at these drawings....is that jug with the handle (bottom set of drawings) similar to the "innovative" concept you were describing that Pyrex did, in your fantastic thread on Press Moulds?

Adam:
Glen - First, to clear up one thing.  When I showed the two "Pyrex" jugs I wasn't suggesting that the second was innovative or some sort of big break-through.  The method has been used before.  I was simply giving it as an example of a very sensible way of getting rid of a two part mould and replacing it with a solid mould - desirable for all sorts of reasons.

Now back to your pictures.  The lower ones show a two part press mould. It is a very good illustration of a press mould, showing the very strong hinge and locking knuckles which are essential.  The jug handle, although being pressed in the way I showed, looks as though it is intended later to be bent down and attached at the bottom.  I suspect there is a bit of artistic licence in the length of handle.

The upper pictures clearly show a blow mould as it is intended to be held shut by hand or by a simple latch with no real strength and, of course, the jug shown could not be pressed in the shape shown.  I am, however, totally baffled by the jug handle which would be impossible to do in a blow mould.  Are the two sets of pictures supposed to tell a story (bottom first) of some sort of press and blow process?  If so they remind me of the sort of fanciful things which often appear in patent specifications although these are clearly not patent drawings.

I am about to go away for five or six days so any follow-up will not get a reply until then.

Adam D.

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