|Nürnberger Meisterzinn - Page 3 of 9
The moulds of Nürnberger Meisterzinn are manufactured from an alloy of aluminium and also consist of two ranges. One includes 8 moulds with infantry and cavalry from the 30-years war (1618-1648), also featuring guns and carriages. The other range includes 29 moulds with infantry, cavalry, artillery and equipment from the time around 1750-1820. Twelve moulds of this 2nd range are of a special comprehensive type, which very systematically have been made to include a number of detachable heads with different sorts of headgear and equipment, facilitating conversion to many different regiments from a huge number of countries in Europe. The moulds of Nürnberger Meisterzinn were marketed in Denmark from around 1978, but are relatively rare nowadays. Some of the moulds can cause a trifle irritation. It has improved the result of the casting that I have made some small air outlets at strategic places with a 1mm drill, and with a file expanded the lead intakes, but the recast percentage is still unsatisfactory. It is as if the lead tends to float less efficiently in the aluminium moulds compared to the rubber moulds, or solidifies before coming out in the cavities in the moulds. For some of the types where I cast a lot, I have simply chosen to manufacture new moulds myself in silicone rubber. Sometimes life is too short for too many recasts.
I often need figures or equipment which is not available on the market. I will therefore briefly touch upon how you can manufacture your own moulds, and accordingly cast your own figures or accessories. Figures from home-manufactured moulds constitute a natural supplement to the marketed moulds. If you wish to convert a figure to another regiment or nationality, it can be done by replacing its head. You can manufacture moulds based on your own designed heads or copy heads from other figures. Likewise it is easy to change the positions of the arms and replace the equipment. The manufacture of moulds and the cast technique by manufacture of own figures are fully described in a number of articles. For example in articles by the President of the Society, Hans Chr. Wolter in Chakoten Nos. 1 and 2 respectively, in volume 50, 1995. The articles can be found at the homepage of Chakoten.
For manufacture of moulds I, like Wolter, use floating, cold vulcanising silicone rubber RS 365 KVG with relating activator RS 3952. This quality is "easy floating" with a good strength and high heat resistance. It does tend to be rather expensive, and in order to reduce the price I purchase it directly from the importer in Denmark. It is marketed in 1 kg plastic cans. By buying 5 kg you obtain a quantity discount, and at the point of my last purchase in 2001 the price was DKK 266.76 per kg, excluding VAT. The activator is supplied in small bottles with 40ml at DKK 19 a bottle, also excluding VAT. The floating rubber can last for many years. I have had cans for more than 10 years without any damage; however you may have to use some time to stir it thoroughly.
Don't be tempted to go easy on the use of rubber in connection with the manufacture of moulds even if you find it expensive. Calculate the volume of the mould before the rubber is mixed with activator in a measuring can. Calculate with at least 1 cm in thickness at the thinnest area of the mould, e.g. the highest point of the subject. In case of bigger subjects, the thickness should be expanded to 1½ cm. It is better to mix a little too much than too little. A mould with thin walls becomes too heated too quickly and will not last for many castings. A mould with thick walls will last long and can endure many castings. One kg of floating rubber has a volume of approximately 600 cm3. I have calculated that the average volume of the last 20 moulds I have made is 186 cm3. This means that you can get 3 moulds on average from a 1 kg can. Rubber and activator including VAT costs DKK 357.20 per can, adding up to an average price per home-manufactured mould of around DKK 120 including VAT. This is actually a fairly reasonable price and only on a modestly higher level compared with the prices of the marketed moulds.
Professional manufacturers of model soldiers use alloys of lead and pewter. Laboratory tests conducted on a number of various brands on the market indicate a mix of around 70% lead and 30% pewter. This alloy is often referred to as white metal. The pewter content tends to vary a little. At a metal dealer this alloy will cost between DKK 50-60 per kg. Pewter of 100% costs a lot more. Lead of 100% costs around DKK 5-7 per kg.
I normally use an alloy of 75% lead and 25% type lead from printers. I don't weigh it precisely from time to time, but fill it into the ladle relying on eye measurement from time to time. Most types of type lead (linotype and monotype) contain 16% antimony and 5-8% pewter, but there are different types, and the content can vary. Antimony is, like lead and pewter, an element. It provides stiffness to the figures and prevents arms and sables of bending. It is easy to judge whether there is too much antimony in the alloy, because if there is, the subject breaks before it bends. If you manufacture figures where you have to bend the arms, you should reduce the antimony content in the alloy. Figures manufactured of 100% lead should not be kept below 16-18 degrees as this may cause lead-oxide. Antimony in the lead prevents lead-oxide. The above alloy with a content of around 25% type-lead containing around 16% antimony should produce an alloy with a content of around 4% antimony, normally considered suitable for both stiffness and preventive of lead-oxide.
As both lead and antimony fumes are poisonous, casting should take place close to an open window and you should preferably wear some sort of breath mask. Antimony alone melts at 630°C, but such a high temperature is not necessary as lead melts at 327°C. Already at 246°C the alloy will start to melt. Pure 100% lead can be purchased from a plumber as sheet cuttings from roofing tasks. It is easy to handle and can be cut in suitable sizes for the ladle with a metal sheet scissor. The type-lead can be purchased from most iron and metal dealers. They frequently have a skip full of it from where you can choose suitably sized pieces from. It is often advisable to bring a small hand-shovel to dig around in the skip, and remember to bring a solid bag to carry the type-lead. Buy plenty of the lead, especially when it comes to type-lead, which seems to be an article approaching extinction. In a short number of years it probably won't exist any more. And when you really get going with the casting, you'll exhaust your supply quickly. You can, however, often get a reduction in the price when you buy bigger quantities.