Casting Questions... (1 Viewer)

[mikemiller1955]

I don't cast metal molds...

never have and probably never will...

I know a lot of you guys do...and understand this process...

Will someone who knows this stuff answer some specific questions for me...

if you can answer any of the questions...please do so.

1) what are metal soldiers made of...what alloys...(please don't answer metal)?

2) what percentage of alloys is a suitable mix or "standard" in the industry?

3) does increasing certain alloys...tin for example...make a metal less pliable?

4) can you make a cast too "stiff"...so it becomes "brittle" and breaks easily?

5) some manufacturers metals seem sturdier than others...is it the mix?

6) what is the cost of the metals used in making a mold?

Anything else you can teach me pertaining to why some manufacturers soldiers are too soft or bendable...as opposed to others that seem to be more sturdy and rigid...I would gladly read.

 

[theBaron]

I don't cast metal molds...

never have and probably never will...

I know a lot of you guys do...and understand this process...

Will someone who knows this stuff answer some specific questions for me...

if you can answer any of the questions...please do so.

1) what are metal soldiers made of...what alloys...(please don't answer metal)?

2) what percentage of alloys is a suitable mix or "standard" in the industry?

3) does increasing certain alloys...tin for example...make a metal less pliable?

4) can you make a cast too "stiff"...so it becomes "brittle" and breaks easily?

5) some manufacturers metals seem sturdier than others...is it the mix?

6) what is the cost of the metals used in making a mold?

Anything else you can teach me pertaining to why some manufacturers soldiers are too soft or bendable...as opposed to others that seem to be more sturdy and rigid...I would gladly read.

Hi, Michael, I'll answer with what I know, as best as I can.

1) "White metal" is an alloy, principally of tin, with other metals such as lead, zinc, bismuth, antimony or cadmium. There are various combinations, all of which are understood under the term "white metal".

2) I can't speak to an "industry standard", the commercial producers will have to answer that. I use old linotype metal, which contains lead, antimony and tin. Mine is probably in a ratio of 3:1:1, though I do add more lead to the pot, when I'm casting using old metal molds.

3-4) Adding more lead will make a softer alloy, tin and antimony add hardness. The more tin or antimony you have in your mix, the more rigid or brittle the final piece will be.

5) Possibly. Again, the commercial producers will have to respond. I imagine that each one may have its own proprietary alloy.

6) The commercial producers will have to speak to this one, too, though you can price the materials to make silicon rubber molds and get a rough estimate. Commercial producers will factor in the cost of creating the master figure. I don't know of anyone using metal to make molds for casting today; the cost increases exponentially. Metal molds are used rather in the injection molding process used to produce plastic model kits. You're talking tens of thousands of dollars to tool the molds, in that case. Silicon rubber molds are much, much cheaper to produce.

I mentioned lead, but I don't imagine that there is any current manufacturer who uses any lead in his alloy today, not after the hysteria of the late 60s and beyond. Current makers use white metal alloys that are lead-free. Older toy soldiers and castings had a higher percentage of lead in them, from Heydes and other German makers, whose alloy was almost all lead, to Stadden's custom figures, which were also relatively higher in lead content. Britain used a lead-tin alloy for the hollowcast line, if I'm not mistaken. Makers of flats, on the other hand, tended to use alloys with more tin and antimony and less lead, for a more rigid casting.

Hope that helps!

Prost!
Brad

 

[mikemiller1955]

Brad...

Wow....thanks....

this is what I call a comprehensive and well thought out and thorough reply...

thank you for taking the time to give me the lengthy detailed answers...

at least now I understand a little bit about the process and metal properties used now...

one more question please...

how do the silicone rubber molds not melt...when the hot metal is poured into them...

seems to me they would...am I asking or saying this wrong?

 

[trooper]

Hi Mike,
the rubber vulcanises, RTV silicone stands for Room Temperature Vulcanising which requires no heat or pressure, commercial moulds are created under a pressure of 10-15 tons at a high temperasture and are left to cook for about 3/4 hour. You need a mould press for this operation and a centrifuge to cast from the mould. Metal prices vary from dealer to dealer. My own personal preference here in the UK is MMX42 produced by Summit Solders. It has excellent flow qualities enabling casting of small, thin items but is still capable of producing thicker sections without surface pitting and crazing. It is quite expensive, about £9/kilo, but has the added bonus of a dross inhibiter whichis a boon. Brittle castings are often the result of an excessive amount of bismouth in the mix while extreme flexibility usually means a higher proportion of lead.
Alan

 

[Wraith]

Hi, Michael, I'll answer with what I know, as best as I can...........

Hope that helps!

Prost!
Brad

Brad...

Wow....thanks....

this is what I call a comprehensive and well thought out and thorough reply...

thank you for taking the time to give me the lengthy detailed answers...

at least now I understand a little bit about the process and metal properties used now...

one more question please...

how do the silicone rubber molds not melt...when the hot metal is poured into them...

seems to me they would...am I asking or saying this wrong?

Good isn't he Michael . Brad helped me venture in to the world of mold making and casting.

I've only used silicone RTV for molds, and as long as the instructions are followed, the molds are fine and hold the detail very well, even for simple drop casting.

 

[Wraith]

My own personal preference here in the UK is MMX42 produced by Summit Solders. It has excellent flow qualities enabling casting of small, thin items but is still capable of producing thicker sections without surface pitting and crazing. It is quite expensive, about £9/kilo, but has the added bonus of a dross inhibiter whichis a boon. Alan

Alan,
Thanks for the heads up. I'll give this metal a try.

Cheers
Simon