Define "hot-dipped" tin plate

[P. M. Cunningham, Tinner]

While I have been out of the field of civil war re-enactments, for five or six years, upon coming back in and looking at what is sold, I see a plethora of the term "hot-dipped" being used and have to wonder, what does that terminology-"hot-dipped tinware"-mean to most consumers? What is it in the mind of the consumer that satisfies his/her reliance on the term in the purchase of a "hot-dipped" processed tinware item? Is this an actual process, a label, or a specification in manufacturing that is used and describing the piece.

I have a fairly firm grasp on what the term means from a manufacturer's standpoint, but the consumer's terminology may mean something vastly different. Interested in seeing how others define this oft used term, "hot-dipped".

Sincere in not wishing to jade a discussion in any way, I prefer to later post my own perspective, and hope for more feedback.

Patrick Cunningham

[Curt Schmidt]

Re: Define "hot-dipped" tin plate

Hallo Kamerad!

While I cannot speak, or presume to speak for the Hobby on this..
IMHO, IMWO, and experience...

"Hot dipped" does not refer to the CW era commercial process of tin plating sheet iron, "pickling process," etc, etc, but RATHER our Hobby has come to look at sheet steel that is heated and dipped (or otherwise coated/covered) with tin/lead solder by a number of modern individuals.
And in some circles the uneven coating and sags and runs are held/prized to be more authentic and period. (So what some vendors have been said to do is to take electroplated sheet steel and coat it with solder and call it "Hot Dipped Tinware.")

Again, this is just my opinion and limited experience, and does not necessarily reflect the views or practices of any actual person, living or dead.

Curt-Heinrich Schmidt
Pickling Bath Mess

[FranklinGuardsNYSM]

Re: Define "hot-dipped" tin plate

It is my understanding that hot dipped tin plate is not commercially available anymore, at least in the United States. Almost all historic sites today use electroplated tin. A very good article on the topic may be found here: http://www.gpmerc.com/news.htm

I have two cups made from antique hot-dipped tin stock that came from England, and can detect very few, if any, differences between them and standard tin stock.

[Agate]

Re: Define "hot-dipped" tin plate

Mr. C.,

As Heinrich has pointed out, unless the body of the item appears to be literally "painted" with material, folks simply don't accept it.

Over the years this has been applied and broadened to include canteen bodies, magazines, et., all "period" tin.

I would argue that it is a widely held belief by the Community. Tis a shame we don't have some of the discussions concerning this from a couple years back for your consideration. I used to groan over the cartridge tin magazine discussions of some time ago.

My favorite personal experience being an argument with a fellow who looked at my original tinned box magazines, and declaring them not to be "authentic" (much less original) as they didn't have that "painted" look. The fellow is well known as a "material culture" type in the hobby, was a hoot. :sarcastic

Some of us have, for years, argued the use of tinned sheet. A subject on which one can at least somewhat educate themselves by simply looking at the MOA site at Cornell, and searching within the "Scientific American," although it unfortunately takes a slight amount of effort, which many refuse to make.

As the term was first introduced on a wide scale to the hobby by the WVM reproductions of several years back, would be most interested on your take, please do enlighten us.


John Sarver
Cincinnati

[BHoover]

Re: Define "hot-dipped" tin plate

While I have been out of the field of civil war re-enactments, for five or six years, upon coming back in and looking at what is sold, I see a plethora of the term "hot-dipped" being used and have to wonder, what does that terminology-"hot-dipped tinware"-mean to most consumers?

Patrick Cunningham

Well, to this comsumer at least, it means that the item better look a lot like the "hot dipped" plate I have that you made :-)

You probably don't remember, but I met you at an MOMCC years ago, and was so impressed with your knowledge and ability that I took your plate as my "gold standard" :-)

[Michael McComas]

Re: Define "hot-dipped" tin plate

I think I was lucky early on to have someone explain to me what "hot tin dipped" really means--tin plated sheet metal, from which an item is fabricated. The tin should form a fine sheen on the artifact, not look like dripped candle wax. Is that the correct answer?

Smearing on solder is one thing. I've seen "hot dipped" goods which were (I suspect) "tinned" with aluminized roofing paint. Needless to say, I don't frequent that vendor any longer.

[smithjub]

Re: Define "hot-dipped" tin plate

Greetings,

I've been reading the responses in here but still have a question. I've seen plenty sutlers selling "hot-dipped" tin canteens, but one in particular caught my eye, offering a choice between getting a tin canteen beeswax lined or hot-dipped. To me it seemed to be implying that the hot-dipped canteen was water tight and didn't need beeswax lining. Reading here that it's just a different type of tin-plated steel going into making the canteen I can't see how that would affect the seal. Any thoughts?

[Curt Schmidt]

Re: Define "hot-dipped" tin plate

Hallo Kamerad!

Kind of an apples and oranges thing that...

Original canteens were not lined with beeswax.
In some segments and among some members of the CW Community, there is a desire and practice to want to prolong the "field life" of their gear as long as possible and definitely longer than the Government Issue issuance cycles and system of the ACW.

At this point you may want to switch over to the SEARCH function and review the threads on "after event" drying of canteens to prevent rusting.

At any rate, IMHO, it is a "modern reenactorism" to want to, and actually do, "beeswax" CW era tin canteens (or get them made in stainless steel).

Curt-Heinrich
Never Had Rusty Water Or Canteens In Two Decades of Play Without Beeswax Mess

[Spinster]

Re: Define "hot-dipped" tin plate

Hallo Kamerad!
Original canteens were not lined with beeswax.

Gee Curt--you are the first one that's made that abundantly clear, at least to my non-military mind. What few times I've used a wax lining to compensate for poor cooperage on a wooden piece, I found it unsatisfactory and wondered why in the world 'they' (as in the 1860 they) did it.

A similar problem relating to tin wear vexes me now. Given that I'm in the field about 26 weekends a year, I figure my useage of repro tin-wear begins to approximate normal 1860 household use. And thats a problem--tin cook pots and pails are significantly rusted within months of purchase, even when I'm careful to use wooden utensils and nothing more that soap and a rag to clean. Within a year, I consider then unusable for cooking, for the water turns rust color before the soup is done. I do note that the one tin-lined copper pot I have has not worn through in the same manner.

I guess I hoped that 'hot dipped tin' would have a much thicker layer of tin on the iron base, thus slowing the rust process.....

[Agate]

Re: Define "hot-dipped" tin plate

Madam,

Your ware may very well may be reacting just as it did during the period. It is tinware after all, very valued to us, maybe more so than those during the period. Not unlike jeancloths dyed using "country methods" of dyewoods. I ask, do we not cherish the stuff? :o

I have found, in the Scientific American, at one point when I was looking into this, some tinned goods that were "improved" or of "extra quality." As I understood this to mean, this was commercially available tinware, that indeed had been made of material specially dipped into a molten vat of zinc or some such, or the material was at least, with a thick layer of paraffin, or animal fats laying on top. I don't know if I could find it again, will give it a shot, and will see what comes of it. Maybe Mr. Cunningham will give us thoughts and we will see if I'm just daft, which sometimes is the case.

However, tinned sheet is not necessarily this stuff. Sheet iron, as soon as it would have been rolled out, would have started the process of oxidation. When we are talking mass production, even in the Nineteenth century, we must keep in mind the amount of time/money that would be utilized in prep work in order to get the materials up to speed to be worked with, considering too, the cost of those raw materials. All the while balancing with the knowledge of the value of the goods to be made.

Just imagine the rust that would build up on raw sheet iron laying in storage! Not to mention that (at least during the prewar period) much of that stuff was manufactured in England and of course, was imported, across an ocean!

It's that material that box tins and canteens were manufactured/stamped out of. A simple coating of tin and oil in order to keep oxidation off of it so it could be utilized in production.

What we have done in the hobby is turn that into something very different, IMHO. One of the most surprising things that I came across at MOA Cornell was the use during the period of something called "taggers iron." A very thin sheet metal, again, from England, which was lightly plated with tin and oil. Want to take a guess at what it was used in the manufacture of?

"Tin" buttons!

In other words, the small stamped, board or metal backed buttons, that were purchased by the millions and utilized on Federal army clothing. If we are to accept the line of thought, these buttons should properly be made of what is termed in the hobby, "hot dipped" tin, and not iron.

As a side, the fact that they are stamped of iron, somewhat answers the question as to why originals are not easily bent.

I would invite you to do a search for that material at the Cornell MOA site.

Federal canteen bodies were made of raw, rough material, stamped probably on what were really nasty steam powered machines, probably as dangerous as all get out, by folks who very well may not have been all that old.

It was the job of the USQMD to spend the people's money, wisely. Beeswax, heavy coats of material, exactly why some of this has never made a whole lot of sense to me, when dealing with, at least, certain items.

But, it's my opinion.

And, I'm not a tinner.

Let's allow those who have studied their due. This, I ask, before any of my rambling on is considered by anyone.

Regards,

John

John Sarver

[P. M. Cunningham, Tinner]

"Hot-Dipped" tinplate, 101

Tinplate, as the word refers, is a coating of tin over a steel or iron sheet. Tin is a basically stable element, that oxides only under acidic or temperature conditions. Problem with tin is that it is incredibly soft. By coating it over a sheet of iron/steel, the tin creates a protective coating for the base metal, while the base metal creates the rigidity necessary for manufacturing goods. But, with use, the coating of tin wears off exposing the iron/steel.

The standard of measuring of tin coating thickness on the sheet has not changed in the last few hundred years. Tin coating is referred to as "pounds per base box". A base box refers to 112 sheets of tinplate measuring a nominal 10" x 14". Taking that amount of square footage (both sides), an amount of tin is used to cover the sheets. Coverage can range all the way down to 1/8 of a pound.

The process involved today can be done either by an elecrolytic or hot process. Electrolysis tends to be the standard practice today. Tinplate tends not to be made for "wares" anymore, so a thinner, more uniform coating is what is more often specified. "Electro" plate will range in coating thickness from 1/8 lb. to 1 lb. (I have often heard rumors of 1 and 1/3 lb being used for the end caps of orange juice concentrate cans but have never found any.)

Hot process is still available commercially today, and this actually refers to placing sheet iron/steel into a molten bath of tin. Most always this plate will be "hot-rolled" coating and have air reduction used to thin the coat to a standard coating thickness. With a "hot-rolled" process an even set of striations will be witnessed in the sheet. These coating thicknesses will range from 1 lb. to 12 lbs. "Hot-dipped" coatings are done as a process today, mostly for the plating of specialty items like industrial restaurant equipment. This process will generally have coating thickness ranging from 8 lbs. to 20 lbs.

Regardless of the process, there will always be pin points where the tin does not adhere to the sheet. This exposes the underlying steel/iron to oxidation whether or not a product is "used" once. With a hot process, however, these pin points are minimalized, thus providing a more protective coating.

Historically, in the mid-19th C., a form of the hot process would have been commonplace. Tinplating, by dipping, originated as a process as early as 1575 in Germany. By 1847 the "hot rolled" process was patented. (Hot-"dipping" vs. "roll" by the 1860's?????). Both were still being done but I have not done nor seen a study on the breakdown of percentage of plate made either fashion. One reference from the early 19th C. describes the plate as having a ten to twelve pound coating. Coating thickness varied through the use of different mechanical or chemical wipes and the number of entries of the plate into different tin baths.

Relationship to the consumer:

Today "hot dipped" is sometimes used in the description of electroplated tinplate (hit the article link posted above in the third post). I spent an hour talking with a tech support guy at Weirton four years ago, and the end result was this plate really nothing like "hot dipped" plate. More often the term refers to "hot-rolled" stock that often has no more tin coating than heavy electroplated material. I have heard of people retrofitting "wave flow" soldering set ups to produce plate, but have not actually seen a product produced in this manner, thus am unsure what the customer believes they are purchasing.

Ideally "hot dipped" should have the historic ten to twelve pound coating to produce a lasting item. The thicker the coating the longer lasting the product, and historically the plate should have had at least ten times the coating thickness as the best electroplated material available today. That relates to a product that can, theoretically, provide ten times the life and one that holds up like originals (no need for wax). Although seeing the term "hot-dipped" (to describe a product line) should make those products more desirable, without knowing the actual process involved and specs. of the material, it may not, however, be a process, but in fact, simply a marketing versus an historical label.

I'll follow this up with "Hot-dipped" Tinplate, 102, "the aesthetic" soon (and probably more ;) ).

Patrick Cunningham

[Amtmann]

Re: Define "hot-dipped" tin plate

I knew there would be a good explaination to all this. :D

[J.H.Berger]

Re: Define "hot-dipped" tin plate

Dear fellows,
the difference between hot dipped and "normal " tin is the thickness of the coating or at least it should be!
I am an artist blacksmith by trade and we work with a similar process with zinc. Electroplated zinc items like nuts and bolts for example have a very thin layer of zinc which starts to rust within weeks if opposed to the elements. Items that are supposed to be outdoors are plated with zinc in a melted zinc bath. The process is/was the same with tinning sheet iron. The difference is that a hot melted bath leaves a much thicker coat of metal (pewter or zinc) on the item. This means that it just takes longer till the iron part under the pewter starts corroding because the pewter is oxidizing first and takes some time to wear off.
That is also the reason why electroplated tin pots start rusting very quickly because the very thin pewter layer just wears off.
The pewter in the copper pans is attached in a "hot dipped like " process, i.e. the inner part is pickled heated and then the pewter is melted in the pot and wiped with a cloth.
So to take it all together. The reason why "hot dipped " tin items are searched for is that they take a little longer till the start to rust which depends on how you care for them and what you fill in them. In the 19th century tinware was not electroplated and so the tinning process was that of "hot dipping".
I know that there are firms here in Germany that custom make hot dipped tin sheet but who could buy a coil with the weigth of over a ton!!!!??
Regards
Jan H.Berger

[P. M. Cunningham, Tinner]

"Hot-dipped" Tinplate, 102, "the aesthetic"

The finished look of tinplate varies depending on the process used in the manufacturing of material. Unfortunately, photos would be nice, but taking shots of tinplate is a pain because of its reflective nature and subtle variations don't always show up. I may try to provide examples later, but for now, it will have to rely on verbal descriptions. From a modern manufacturing standpoint, the breakdown is as follows:

Electroplated tinplate

Electroplated tinplate can be purchased with either a matte or bright finish. Bright finish will generally have a perfectly even coating that has mirror-like tendencies. This reflectiveness will be related to the coating thickness, since the coating thickness can get so low it's luster can be diminished. Matte finish has a look slightly like very fine sandpaper and a dull coloration. Occasionally, I have seen matte used for repros of 19th C. goods but it has been awhile. Bright finish is still commonly used.

"Hot-rolled" tinplate

"Hot-rolled" refers to a process in which tinplate is produced in a continual coil, which can involve mechanical, flux, and/or air jet reduction. The determination of the final operation as the metal comes out of the vat creates the final finish. Every piece I have seen entails air reduction of the sheet. Simply put, a set of evenly-spaced jets shot air onto the plate as it came out of the vat, making the sheet have an even coating. This will result in the plate having striations evenly laid out across the sheet. In a sense this would look like current on a perfectly smooth river. This visual look comes about in the 1922 samples of plate and the last English plate that was imported in the 1980's.

"Hot-dipped" tinplate

This process involves actually dipping the piece(s) into a molten vat and pulling back out. A mechanical wipe may be used, but usually only a chemical wipe is used. Depending upon the final system involved, the look will vary. At some point, I had six different companies produce dipped plate for me and nothing ever looked the same from company to company. "Hot-dipped" will look slightly painted simply because of the amount of tin. Coating thickness will vary from the top of the sheet to the bottom simply from gravity. This plate may show large crystal patterns or small, pending on the cooling process and patterning will vary because of the different chemical interactions (tallow, palm oil, argon....).

Because every style of plating creates a unique cooling process the tin cools with a unique crystal pattern. Generally this is only evident through the use of wiping the plate with an acid solution. The process called etching (crystallization in the 19th C.) was done as a decorative element on products like trays in the 19th C. and then transparently coated with asphaltum to create a tortoise-shell look. Electroplated tin will generally have a crystal pattern of about an 1/8" to a 1/4" that is scattered. "Hot-rolled" plate will produce a larger pattern but will still show some striation to the pattern. "Hot-dipped" plate will provide upwards of a four-inch crystal that will be very random.

What do we see on mid 19th C. tinware? Very hard to define. Unfortunately, there is no untouched box of raw plate from the 19th C. about which I am aware. By looking at little-touched artifact parts, some clues can be derived. Interior of product, like the inside of box lids and cartridge box liners, give a clue. Generally, the look tends to be "visibly" thick. At least one artifact I have seen actually had a coating drop where the tin above reached too high of a temperature and caused run to a moisture line. Sometimes the crystal pattern shows up, but generally not. Those pieces that show crystal evidence tend to look like they were produced using a "hot-dipped" process.

Occasionally, color discoloration is seen in the plate in yellow and blue hues. This probably is a result of vat temperature. Color discoloration can be attributed to product that was sold as "wasters" in the 19th C. Like the term "taggers" not all tinplate was produced with the same quality. An 1837 French tin manual actually talks about going through a box of plate and picking out the best material to planish out to achieve a "gold lustre". Apparently even the "good" plate had variations in the quality in the box. My best guess of a finished look: even but slight ridge variation because of thickness, smooth-looking but possibly showing some minor crystal pattern.

Relationship to the Consumer

Does the look make a difference? As a new product there is a visible variation that is evident. If a piece is only out as a prop (i.e. sealed food can) there will be a noticeable difference in the material. Once a piece is used/abused the initial process is not as evident. What comes more into play at that point is not only the process involved but the coating thickness of the plate itself. By having period coating thickness, period wear patterns develop appropriately. A 1 lb. coating will result in different wear patterns than a 10 lbs. coating. Oxidation patterns will become evident through the simple handling of the product. Thus, how the tin cooled becomes evident in patterns.

Now that the basics are covered, coming up next "Hot-Dipped" Tinpate 201, Personal Experience (pictures for that :wink_smil )

Patrick Cunningham

[55th VVI]

Re: Define "hot-dipped" tin plate

These post about hot dipped tin have been great. It would be nice to see these placed in one of the article folders.