Half moon repair on bottom

[sandchip]

ORIGINAL: westernbittersnut

This unique anomlie has already been explained. First off this mark is NOT caused by any repair nor should it be referred to as a repair. It is very easily understood if you are familar with the glassblowers operation of making a bottle.

This feature is a result of the glassblower getting the exterior surface of the expanded bulb of hot glass pinched between the two mold halves as they close. When opened quickly to release the gather of glass from its confinement the mold is closed again and the fold of thin glass is pressed against its exterior as it expands against the molds interior walls. This feature can occur anywhere on the exterior surface of a bottle. They are fun to find and just confirm that the glassblower is not perfect in his profession all the time.

Dead on the money, WBN!

 

[westernbittersnut]

Warren,..I'm pretty sure Red is familier with glassblowing operations considering his background and experience...[]
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Joe,

He might be, however to understand exactly how this could happen you would have to read first hand observations of the glassblower's work back during that time.

 

[cowseatmaize]

hot glass pinched between the two mold halves

This is where I'm confused. How can this happen where there is no proximity to a seam?

 

[westernbittersnut]

ORIGINAL: cowseatmaize

Can you post a few examples Red and or Warren. I still don't see it. What I see is a piece of glass that got stuck to the base of the mold and picked up from the next blow or a piece of unmeleted fragment stuck in the gather. It looks about 45-60 degree offset and covers the hinge mold in that area yet let some gather go around it. I'm just trying to follow the raised outline of the suspected piece and the rim trying to get around it. The jagged part at the bottom confuses me also. Not that that's hard to do.
I realize how unlikely a blower could have missed something that obvious unless there was a big rush on quantity and that's why Im asking. I also know there is nothing but holding it that can really show the detail.

Eric,

That "half moon" piece of glass is still connected to the gather of glass that was extended in a bulbous shape and inserted into the mold. If the glassblower does not position that gather of expanded glass in the center of the mold its outside surface edge whether the bottom or sides would get pinched, causing the outer edge of the gather to be squished between the two mold halves as they closed shut, opening the mold to release the restrictive movement of the glass on the end of the blowpipe would show this this thin flap of glass (curved on the outer edge due to gather having a bulbous shape and straight on the inner edge because of the inner molds straight edge. That glass flap is then folded into the glass vessel itself because the gather is expanded to the molds inner dimensional shape when the blower continues to expand the glass fully into the molds cavity.

 

[cyberdigger]

Have I absorbed my information incorrectly, or does this formation often occur in the parison mold?

 

[westernbittersnut]

ORIGINAL: cowseatmaize

hot glass pinched between the two mold halves

This is where I'm confused. How can this happen where there is no proximity to a seam?

Because the partially expanded gather of glass after being pinched from NOT being centered in the mold cavity is released the glassblower repositions this bulbous gather of glass in the mold which causes this flap to not necessarily still remain exactly in the same location or position as it had been.

 

[GuntherHess]

I believe that if a piece of glass is pinched in a heavy iron mold its going to cool very fast from the heat sinking of the iron mass. This will make the pinched flap much less plastic than the rest of the hot gather. Thus seam impressions and embossing would not show up well on this flap. Possibly explaining why there is no seam impression acros the flap.

 

[JOETHECROW]

This subject comes up fairly often,...and is kind of weird...I know Red has studied on it quite a lot, and I'm not sure what I think about it, but it's kinds cool, and they all have the same shape "indent/pinch" whatever you want to call it....also great explanation Warren...sounds plausible to me. The only bottle I have an example on is this umbrella ink.

 

[JOETHECROW]

So if I understand,...Gunther's saying that the glass in this area was too cooled to take on the impression of the seam? That makes sense.

 

[RED Matthews]

Well all of you I am really glad to see and review all of the comments on this thread. I will try to review the thread again and post some replies to some of your requests, this way. First of all cowseatmaize:[/b] Please go to my homepage and read the blog I put together to explain these Half-Leaf Marks with my concepts of the characteristics I have detected with them. http://www.bottlemysteries.com/2009/04/bottle-mold-cavity-half-leaf-repair-marks/ The first picture illustrates part of a half leaf repair that was done on the neck of the mold. It is obvious that after the bottle was released from the mold, the finish was applied and tooled directly over it. The picture under that has a full half-leaf in the mold face embossed lettering area. The next set of three pictures shows the repair mark and the third one also shows the cloth texture common to this mold metal stick welded repair. When the welding metal sticks are melted and drawn out to be welded in the machine cavity for repair, the carbon particles in the metal are reduced in size and after the welding and riffeling of the surface to match the cavity form. The hot glass that comes against that repair area lifts the small iron specks out of the iron giving the appearance of cloth having been against the hot glass of a bottle. In the Antique Bottle and Glass Collectors magazine, the barrel bitters bottle would not have looked like that if the glass was blown against a glass flap of glass. When I posted this blog there were several pages of post in the thread that kicked it all over the soccer field. I have been involved with mold repair methods and the repair welding in the mold cavities for many years. At one time I even imported a special iron welding rod from the Universal Tifpunkt Company in Germany for us to use when electric in the # 4 Kelley Foundry mold iron. We did some welding with sticks of their #4 iron that was cast using drinking straws for the mold sand in the cope and drag casting the foundry. So I will now go to the next post with other attempts to answer the confusion of these marks. I already commented in this thread on the half leaf on the bottom of the French bottle that it could not have been a mold repair because it straddles the bottom mold mark, so it had to have been a pinch of glass from somewhere. I just can not conceive that it could have gotten from the straight vertical side of the glass pinched near the top of the side seam of the bottle and then land across the bottom of the bottle in the mold, but that is the only possible source. I would have to get my hands on the bottle to know more about it and study it with some magnification. I also do not understand the rounded bead of glass around the periphery of the leaf form with out a magnification. To cyberdigger; [/b] Your bottle picture is a nice example of a mold cavity welded nick repair in the mold. I will study the picture some more. To westernbittersnut;[/b] My reply here is to point out again that we have to determine the shape of the gather of glass on the blowpipe, in my opinion had to have been formed in a parison mold. It this was the method of manufacture that was used then the shape of that mold could have made a pinch of the shape, but I have still not been able to depict in my mind how the straight line was formed. [/b] [/b] In my homepage blog on the subject of “Half-Leaf Mold Cavity Repair†I can see where the straight line came from. It was a straight line because it was the linear path of a milling machine end-cutting small diameter cutter of possibly a ¾†diameter cutter on an angle and fed deeper as it cut into the mold and at the midpoint length of the damage it was then lifted out of the contact of the mold cavity.[/b] [/b] In my homepage blog I had Jim Hogenbach’s permission to use his pictures in the Antique Glass & Bottle Collector’s magazine from April of 2009. I had been gathering material for my blog at about the same time he was.[/b] At this point I have to accept the fact that this one on the bottom of the bottle had to come from some action that is not yet explained so I can accept it. If a parison mold was used I still can not explain the straight side on the one on the bottom of the bottle shown above.
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