Litho Question

[mike van]

Just curious about the process and how it's done. Are the parts painted before being bent? How is the paint applied? Has anyone ever seen it being done in a factory? Thanks - Mike Van :unsure:

[larry seven]

:) Mike van, I read a description of the process in one of the 'Collecting Tin Toys' books, but at the moment, I can't find that book. I may have sold it. I remember that the ink (not paint) is applied to the tin sheet and then allowed to dry, step repeated for each color, before the tin is cut, pressed, and trimmed to the shapes that will be assembled into the toy. I think that it is amazing that any of the details, such as eyes and mouth art work actually line up where they are supposed to go on the finished robot. Sometimes you may notice that a rivet detail is slightly off from where it should be, let's say, on a raised dimple in the tin that should be a rivet head. But generally, it is well done, especially on the nice old robots. -Larry 7

[Chief Robotman]

You may find this article interesting from artoodetoo.com

The process of making a tin toy is pretty interesting, and surprisingly labor intensive. Most of the assembly is done by hand, an expensive proposition in today's economy, and probably one reason why tin toys gave way to their plastic, machine molded and assembled counterparts. All parts of the toy start out as flat sheets of thin metal. The design is lithographed, or printed on the sheet, and then cut out. The part is then put in a die stamping machine where it is given shape. Since the flat metal is often formed into complex curves, there is a certain amount of stretching of the metal that occurs in some areas of the part. Also, a tight radius can cause the metal to wrinkle, because excess metal has nowhere to go. Detail in the part is often in low relief, since stretching the metal too much, as in a sharp bend or deep relief could cause the metal to tear. As a result, intricate relief was either painted on or left out.

Lithography itself is the process of printing to a flat surface from a negative plate seperating the oils on a continuous drum roll prcess or press.

[duxastrogirl]

I am guessing that the press to give the flat tin shape has two parts -sort of positive and negative of the shape of the toy- So the tin sheet is in the middle?

I wonder how they do no to damage the litho on the pressing process.

[Dirk]

Be sure - there had been many problems. The toys are lithoed first - and bend later. But this was many hard work to do before you got the right mold and the right litho. If you bend an "o" you will get an "egg" later. If you bend too sharp, or the molds fit not 100%, you get a hump or a hole. Sorry my english is much too bad to explain. Befor the cheaper japanese tin toys bring us down - we have had great manufactures for tintoys here in Germany. Many of the know how ! you need, will be lost forever, I think. I like to add 2 pics - you see the molds - the toy - and the moldmaker with a magnifying glass at his work. But you need more . . . the right material - the right maschines ( pressure up to 100 to. !) and much more. . .

[Dirk]

You see also, how extremly the tin + litho was bent. You must have an exact deformed litho, to get a perfect shape later... see for example the letters: "POLICE" :blink:

[duxastrogirl]

Thanks Dirk! Photos are very clarifying....Makes me admire even more the toys and the makers!

[robert]

You see also, how extremly the tin + litho was bent. You must have an exact deformed litho, to get a perfect shape later... see for example the letters: "POLIZEI" :blink:

Dirk,

Are you sure that is TIN? Looks like vacuformed plastic to me. Note the holes in the top and bottom of the molds used to vacuum the air out. I do not believe that tin can be stretched and molded to the same degree that is shown in those cars without tearing. If you look at molded tin cars from the 50's you will see that the shapes are kept fairly simple - convex or concave but not both combined to any great depth. By that I mean if you are going to make a piece of tin convex or egg-shaped, you are stressing the metal to create that shape so it it extremely difficult to then take that same piece and stretch it in the opposite direction (concave) without reaching the limit of the metals' pliability. When you throw lithography into the mix it becomes even more difficult, as the litho has an even lower stress threshold than tin by itself. The litho would tear, leaving the bare metal underneath exposed.

[Dirk]

Robert,

puh... I've got it - YES DEFINATELY TIN. Indeed the edges look like white plastic, but this must be the already lithoed surface. This later tin toys ( late 50th & 60th) are made of a very thin steel tin - only 0,25mm to 0,2 mm thick. This material could resist the extreme forming process. THANKS for describing the difficulties in the forming process so accurately, Robert!!

Later - You are right, Robert - the companies used many kinds of plastic. But this is tin - here is the finished toy ( ...to pic 2). I could not find more information to pic 1 - maybe it is only a plain white sample, to see if the mold fits

Also I must add, that I'm not a real expert in lithoed tin toy production. I only think you need a lot of experience & know how to do a very fine toy.

[Volker]

Hello,

yes Dirk you are right - this is a tin-mould - for a vacum plastic -part, you need only one side.

not two parts - tool.

This Tin was verry thin and the Germany companys was the Master of the tin-former.

regards

Volker

[Joe K.]

See page 229 of Blast Off!

[Dirk]

Hi Volker,

thanks for your help. What would you think about a little robot-meeting in Brüssel on Sunday ?? Claus?, Gernot!, Eric!, Dirk!, ..... Volker ? ... anybody else...?

Joe - thank you - now I know why the japanese toys are so cheap & the germans too expensive...lol :lol:

[Volker]

Hi again,

I will contact you for the meeting at sunday.

by the way here a Picture of the steps for the Body for the Strenco- Robot.

The Tin is verry thick for a TinToy and we must made many steps till the real form.

the Tin is 1,2 to 1,5 mm .

first part is the tin-plate for the left and the right site.

cu

volker

[(id)]

Volker, that image is fantastic, very evocative.. It's like watching them being born. It never ceases to amaze me that these little creations start as a sheet of metal and then have so much personality in their final form.

[mike van]

Thanks for all the info. everyone, you can keep adding to it if you like - The whole mfg. & litho process is nothing short of amazing. I'm looking at a Mechanical Mighty Robot on my desk, 5 different colors, many bends & angles, and it shines like new. An awful lot of work went into this for a toy that probably sold for less than a dollar. I hope this dosen't become one of the "forgotten crafts" as so many others have. mike van