The tour is of capital importance in the history of industry and craftsmanship. Quite simply because it is thanks to it that we have built so many tools.
It should not be borne in mind that it was used only to make pottery or beautiful wooden ornaments.
By manufacturing tools, we were able to manufacture other types of lathes and by manufacturers other types of lathes we were able to manufacture other types of tools, etc ...
And when man has mastered iron, steel and cast iron, the lathe has become an important machine in any good workshop.
Ideas for turning a lathe have never failed, as well as giving it the strength to do heavy work.
To turn manually or on foot, by all kinds of ingenuity. Then by steam, hydraulic and electric power.
Giving it strength when necessary is done by systems of pulleys and gears, not to mention human strength.
If the lathe had, at one time, a certain manufacturing versatility allowing it to do all kinds of work, it soon became a machine for making only this or that. Transforming into a multitude of specialized machines for a specific type of manufacturing.
We will now draw a parallel between the second part of the 19th century and our modern era.
Bulletin of the Museum of Industry, Jobard, 1858:
Let's start with 1858. While understanding that these writings date from 1858, we will understand that these techniques obviously date from before that date.
Here is the description of polishing and cleaning copper.
We will understand in this description that a piece of copper formed on a lathe contains traces of this work and that the means of eliminating these traces to give a beautiful shiny and smooth appearance to the copper are not complicated:
"Either the metal works were finished using the file, or they received their shapes on the lathe (therefore, we read here that thanks to the lathe we can give a shape to the metal), we are in the practice of subjecting them to a final preparation intended to impart to them all the brilliance and luster which they are likely to acquire.
This operation is called polishing, it has a certain analogy with the methods used to polish wood concerning labor, but it differs essentially as to the substances to be used. We understand in fact that the latter must be hard enough and biting enough to cut into metals, because any polish necessarily supposes the action of wear. The most commonly used substances are: emery, powdered Levantine stone, and English red, when it comes to polishing iron. For copper, water stones, pumice, charcoal, tripoli and rotten earth are used.
Emery is a very well-known mineral substance, and of such hardness that it wears out all metals and even hardened steel. They are commercially available in all sizes, from grain emery to that used to polish steel, mirrors and optical glasses. We call Levantine a kind of limestone sandstone that comes to us from Turkey. The red colchotarou from England is nothing more than an iron oxide of a beautiful red color. There are several degrees of hardness. The softer one is used in gold and jewelry. The hardest species are used to polish watch pivots. The water-based stones employed in polishing copper present a rather great analogy with slate, but they are of a more siliceous nature than the latter. Everyone knows the mineral that has received the name tripoli, but it is generally not known that it appears to be composed of myriads of small fossil shells.
If it was a question of polishing a turned part, it would be achieved much more quickly and easily, because one could use the rotational movement of the lathe, which would avoid the boredom and fatigue of a prolonged movement. We would then take two planks of soft wood soaked in oil and emery and grasping them at each end, we would clamp the piece between two, then walking them in all directions, we would easily obtain a very fine polish. For the rounded parts, we will use a piece of wood flattened by the end. The re-entrant angles will be polished with a board thin enough to penetrate them. In a word, one should always adopt polishers of appropriate shape to the moldings which can meet on the work.
The first method which we have indicated for polishing the wrought iron with a file is so long, that we have had to find ways of reducing the labor. This has been achieved by employing for polishing a series of grindstones furnished with emery, which, by a rapid rotation, impart a very fine polish to the works in a very short time, provided, however, that their shapes can lend themselves to this kind of treatment.
Copper, due to its lower hardness, polishes much more easily than iron and steel. We start by softening it with water stones of different grain. We then pass a charcoal also with water and when the surface begins to polish well, we continue with pieces of soft wood coated with oil and pumice stone or tripoli. We finally end with rotten earth, first in oil, then dry.
Polishing turned works is even easier and faster, because the copper comes out, so to speak, polished from under the tool. And to finish making them shiny, most of the time it suffices to rub them for a few minutes, without removing them from the wheel, with a cloth soaked in oil and garnished with tripoli or rotten earth. "
Annales Industrielles, Frédureau & Cie, 1892:
Let us now take the explanations concerning the trade of turner-repeller in 1892.
I would make the same remark as before, the writings date from 1892 but what is described there is obviously older:
"Turning: The turning comprises two main branches, the turning on copper and the embossing. The copper part to be turned must be fixed in the wooden part or mandrel intended to receive it, and this without degrading these mandrels which are of a certain price. Before attacking this part with the tool, it must turn well. The metal surface will then be attacked by holding a firm hand. Most lathes now work by steam, which makes the job less tiring than at the footwork which required a double expenditure of strength.
Embossing: an operation which consists in covering with a sheet of copper a form or mandrel, according to the model requested. It is a very delicate operation, very difficult, but very interesting. "
"Turner and repeller: Turning on copper and embossing require a certain development of strength. Therefore, we do not recommend these two trades to delicate or puny children. The apprenticeship here lasts three years. The first year should be devoted. to tooling, forging tools and to the study of indentation: this is one of the most delicate points of the trade.
It is also essential that the training be done on a foot lathe, first to know how to handle it and then, because the steam lathe presents dangers for an inexperienced hand.
It is necessary to go through the different specialties of the turn, if one wants to become a capable worker. The worker must learn to grow and reduce a molding without altering its profile and this quality, very useful for the assembly of porcelain, is encountered quite rarely.
The education of the eye is therefore, in all branches of the bronze industry, a very important point.
Nothing is done faster than to completely distort the character of a profile and the worker must learn to see and respect it. A defect to be corrected modifies a part, and it is necessary to know, using the hammer, to bring out the part if there is a recess in the proof and not to thin a profile to remove the defect.
To make a mandrel exactly, it takes great accuracy of the eye, great practice in handling the compass, because the worker must faithfully reproduce the profiles entrusted to him. "
Now how can we draw a parallel with our time?
We are very fortunate to have today in the USA, the EAST COST TINNING house managed by Jim Hamann.
And here then, put into practice (more or less), in our modern time, the know-how of our ancients. And I would like to point out that this is not done in a 1 or 2mm copper foil but in a 3mm copper.
It will be understood that Jim could very well, with the equipment he has, reproduce an identical Schwabenland type copper pot.
Just as there is no doubt that a 19th century turner-repeller could also have done:
It is by reading the texts of the 19th century and watching Jim and his team at work that we understand the full meaning of the words: craftsman, know-how, perpetuating tradition.
Another example :
Le Génie Industriel, Armengaud frères, 1864.
Stamping of the pot:
"Stamping machine, operated by a hydraulic press. The piston of the press which goes up vertically carries a mandrel on which the copper plate rests. This one has a diameter greater than that which must have the bottom of the pan in order to be able to form the edges. "
I skip over the rather complicated technical details. In short, the hydraulic piston will push the copper disc and the techniques used make it possible to obtain a pot with a bottom which retains its original thickness and edges which are perfectly smooth. These edges do not define the purpose of the height of the pot. There is still work to be done.
"The stamping finished, the pan undergoes one or more annealing then it passes to the lathe which sets it up and polishes it. The lathe is provided with a mandrel intended to receive the saucepan. On the bench of this lathe there is a carriage. which can come and go in the longitudinal direction. On this trolley there is another support provided with two rollers which can move closer or further away from each other to compress the pan on both sides at the same time . These rollers being brought to the edges of the pan and put under pressure, it suffices to move them longitudinally to stretch the metal. Thanks to this arrangement, we can thin at will and lengthen the middle of the rise of the pan without touching the bottom and at the top edge. "
We can obtain by this method, a copper pot with a thick bottom, thick base rim, thinner middle of the sides of the pot and thicker upper rim.
I am stopping here for now. But there is a lot more to say about this topic. Other techniques, other ways of doing things ...
To all Copper Lovers!
Regards, T.J.
STAMPING, WORK ON LATHE, POLISHING OF COPPER PANS AND POTS
This page is not my complete work regarding the use of stamping, lathe working and polishing copper pots from the 19th century. It is only a summary that I will present here, in "the urgency". I will come back to this with the 1820s as a starting point and a lot more stories and details when I have time.
To begin with, it must be said that the lathe is one of the first machines used by man.
And certainly the most important.
It would be very long and tedious to tell the story of this incredible machine that revolutionized so many things.
I will try to do this without being too long and boring as it would take pages and pages to talk about it.
Giving out the technical details would quickly become boring for many people.
The lathe has been used for so long that it would be unwise to say since when!
Either way, it was valuable for working with wood, pottery and then metals.
I would ignore the part of the history of the tour at a time when it was considered an essential tool for the good education of well-off people.
Louis XIV by being a great enthusiast and skilful user. In its day, guilloché lathes were used to work with wood or metal.
We are fortunate to be able, today in 2021, to see what Louis XIV could do with this type of machine. And you will agree that for this time, the end of the 1700s, it was something great! I think more than one of you will be surprised by this:
