Mold Cavity Half-Leaf Repair Marks

[baltbottles]

Kentohio you are exactly right on how this type of defect is formed in the glass. If you ever get the chance to see one in cross section on a broken bottle its clearly two separate layers of glass. And it was not applied over a hole in the bottle either.

As you stated while trying to close the mold the gather got partly caught between the two mold halves and was cooled into a pressed fin shape. This would not have allowed the mold to close properly then the mold would be reopened and the gather turned in the mold pushing this fin flat against the side of the gather then the gather would be blown to create the finished bottle. This fin of glass haveing been too cool to take on the shape of the mold very well. This is why these don't usually have embossing on them. This also explains why these types of defects tend to be vertical in nature running parallel to the mold seams of the bottle. However they do not have to be near the seam its self due to the turning of the gather in the mold before blowing. This lapse in time between the turning and the blowing could also explain why some of these are not always perfectly vertical but may skew slightly to the diagonal

Furthermore if this was a repair to the mold itself then there would be many of the same bottle with a matching defect. I have never seen two of the same bottle with this defect that are identical in size shape and placement.

Chris

 

[cyberdigger]

I can't help but wonder why they all seem to be EXACTLY the same shape? Why wouldn't some of them be a bit less uniform? And to have two bottles, 150+ years old, from the same exact mold anywhere at the same time and place nowadays seems unlikely at best.. just wondering.. and reading everybody else's contributions with a healthy appetite for a civilized debate.. and with respect for everyone's ideas..

 

[Oldihtractor]

Here's a cocalt version same thing..

 

[dollarbill]

Heres one in a diffrent direction than most I've seen in and early crown top .
bill

 

[dollarbill]

MMM not so good a pic .I'll try agian

 

[tigue710]

Chris makes a very valid argument, but the pinetree seems to be evident that the gather was not re positioned in the mold... I would think that if that little flap cooled enough that quickly then the rest of the gather would also have to have cooled significantly. Remember glass is conductor of heat, although it makes for a good insulator too...!

It is still unknown and very highly debated exactly how these marks were caused...

I personally think they are blown out bubbles that were tooled after coming out of the mold with a special technique, but you have me thinking Chris...

the only similarities I see in every one is that they all exhibit characteristics of having been folded into the bottle, and the never fully take on the mold shape. They also never seem to be pushed in, which I think is the strongest evidence for Chris' case...

 

[RED Matthews]

Hello again; cyberdigger and the rest of you. I am still absorbing all of the comments and trying to put together some more information on this subject. I feel that I have seen a lot of mold repair in the more modern mold shop practices. I have worked with problem molds that had to be welded to correct errors, mold seam knock-outs, and accidents. These older marks are really the result of a nick having to be milled out with a milling cutter, and the similar metal welded back in. That is why they seem to take on the half-leaf shape.

The idea of the mark being from a hole repair, just doesn't fit my logic; because a bottle with a hole in it would simply be thrown into the next crucible back in the line up and remelted in the fusion process. These bottle makers were obligated to make several hundred bottles in a shift and no one could justify messing around with patching an individual bottle. The costs of making a mold set is enough to justify welding and benching the cavity back to a usable form. I am sure that an individual bottlemakers shop would have had to have at least ten molds for a specific bottle run. I also know that these early bottlemakers put their individual makers marks on their set of mold bottom plugs - flat, domed or pushed-up. These marks will be illustrated in a blog I am working on right now, showing the makers marks, cone dots, crosses, the number 3 - with the the top curve of the 3 made like a > elongating the height of the letter. There are also + signs, large * marks, X marks, and 1/2" square embossed shapes.

The proof of this half-leaf shape being in the mold, would be finding two of the same bottles with the same marks. I haven't been able to accomplish that in the last three years; but I am sure they are out there. Unfortunately, the practice of using mold numbers, didn't really get started until nearly the end of the 19th century.

Just part of my feelings on the subject right now. Keep up the thought process and realize that a bottle is formed from a parison shape which is placed in, and blown, in the final mold to shape the bottle and produce the detail in the striking of the hot glass to the mold surface. It is possible to create bird swings by having the inside of the parison walls touch each other, but there is not any flap making process and if there was it would just produce tramp glass inside the bottle.

Thanks to all of you for your imput. RED Matthews




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[baltbottles]

I'm sorry but if any of you actually studied glass you would have seen a few of these. there is no way they could have been produced any way but how I have described. I have dug quite a few examples of broken bottles with this type of blowing error and there is no hole that was patched. I honestly wish I had saved the shards simply for this thread. The next one I find I will. I have several bottles in my collection If I could photograph the inside you would plainly see. That there was never any hole that was patched.

Lobeycat, The picture you posted shows the flap tilted to a diagonal this occurred in the time it took to turn the gather to properly close the mold. Think about it for a second you have a mass of molten glass affected by the effects of gravity this caused the gather to elongate and being the consistency of molten glass is highly viscous it slumped unevenly causing the fold to rotate to an angle not parallel to the seam. Take the time to read my first post. It states that all blowing errors of this type are not at exactly the same angle as the seam. Also being near the seam line or far away from it simply has to do with the amount of degrees the gather was rotated by the blower this would likely be different everytime.

Tigue, the gather in the pine tree was repositioned that’s why after being pressed in-between the the seam of the two mold halfs being closed the fin was instantly cooled by likely several hundred degrees enough causing it to solidify to the point of no longer being able to accept a mold impression thats why part of the letters in the phila are missing. The larger gather had enough mass to hold heat to still be in a plastic state to be blown into the shape of the mold. Also the rest of the gather likely still hadn’t touched the inner surface of the mold allowing transference of heat energy to occur. Thus not being cooled rapidly. Until the blower applied air pressure expanding the gather to the inside of the mold allowing heat transference to occur in the rest of the gather. The flap on the other hand had enough contact with the mold to be cooled before the rest of the gather was expanded.

Also don't you think it would have been easier and more technically possible at the time to simply grind out a chip in a mold and rivet in a slugplate as is seen on many a repaired mold.

Further more the study of molds is a specialty of mine I have had many examples of bottles blown in the same mold well after 150 years of being made. If this weren’t possible then would the Mckearin numbering system of historical flasks be possible? Its simple there are a finite number of molds by studding the intact examples and known shards one can from comparison determine the number of molds of a specific bottle.

Also the idea of brazing to replace cast iron in the mid 19th century is crazy the first "Acetylene was discovered in 1836 by Edmund Davy, but its use was not practical in welding until about 1900, when a suitable blowtorch was developed" quote from wikipedia. So to fill in these molds with the same type of metal was imposable with the technology at the time. Being the melting point of cast iron is nearly 2200 degrees Fahrenheit

I apologize for sounding arrogant but if you look at one of these in cross section its plain as day how it was made.

In the end show me two exactly indentical bottles with the same error to the fraction of an inch and I will eat my words and say it was a mold repair. Until then Its a blowing error if you don't want to open your eyes to this that is your problem. And if you want to keep passing along incorrect information so be it.

Also RED this was ment as no offence to you but this may have been the way to fix a mold in 1965 but we are talking about bottles from the 1840s-60s you have to take into account the tools and the technology they had to work with at that time.

Chris

 

[justanolddigger]

Chris, your logic is well thought out. I had to read what you said a couple of times to actually follow what your were saying, but after doing so, I did "get it" and I agree with your train of thought. I think one thing that supports your logic is that all of these flaws tend to run lengthways down the bottle due to the sag in the molten glass. I am really going to start to look at all the broken stuff I dig to find a flaw like that so I can see the layers of glass, that would be the clincher for me. I have several bottles that have come from the same mold. It seems the pinetree cordials are some of the easiest to pick out, the have many little pecularities that make each mold unique.
Bill

 

[tigue710]

Lobes, a chunk of metal welded in the mold wouldnt leave a mark like that, I've never seen a weld seam that thin! have you?

yes, I've seen many earlier mold repairs and they were always ground or cut out with a plate being rivet back in. The bottle cyber posted is proof alone that circular wheel was not use to grind out a defect because the half circle faces the mold line in an angle that would of been impossible to cut with a wheel.

I do believe if there was a quick process to repair the bottle out of the mold it would have been done because the blowers were paid per piece, and would not want to toss out a perfectly good bottle if they had a quick fix.

Chris, there would not be evidence of a filled in hole because the flap is the hole, if a bubble blew out it would have been possible (I think) to grab one side of the hole and pull it tight to the other, over lapping the flap and pressing it back into the bottle. My only problem with that is that I would expect the bottle to have been deformed in the process. That is exactly what I was asking in my letter to Jim in the magazine last month, and it is what has left me not 100% convinced that a solution had been found with the repair explanation. In fact I had been thinking that it seemed the bottle was expanded in the mold after the repair.

It could also be possible the the gather blew out before being put in the mold, and the use of a tool to fix the whole cooled the flap?

I'd have to say though that I'm 98% for Chris' explanation, I think it makes the most sense and all the evidence I've seen supports it.

Still a question of the gather itself being pliable though. I have seen glass blowers adding detail to glass with a color rod, holding it with their bare hand at one end and only a foot away on the other end the glass being liquid enough to apply it to a piece... So I guess it it possible, but if the mold was properly pre heated it shouldn't have cooled the glass to such a degree.

One other question is the texture found on a lot of these repairs, as if the had been tooled... The molds were not as thick as a lot of these wings, so it rules out the texture being from the mold wall, and if it was turned in the mold wouldn't there striations in the flap from this turn?