GRAVITY OR DROP CASTING

Casting toy and model soldiers, jewellery and many other items is an increasingly popular hobby. Commercially these sorts of items are cast in special centrifugal casting machines, these can be very expensive. Gravity casting allows similar results to be achieved at home with a minimum of equipment. There are also ready made vulcanised rubber moulds available through model shops to cast a large variety of well sculpted figures.

To achieve best results in gravity casting there are a number of points to consider (fewer than for machine casting) and we would be pleased to offer advice to anyone experiencing difficulties.

Pewter is an almost perfect centrifugal casting alloy but can be difficult to drop cast (select Pewter S or H1 ) there are a number of alloys which are totally unsuitable for the process and only a few which are especially good. We have listed below a number of alloys which are appropriate for gravity casting.

Further considerations in alloy selection are:-
CASTING TEMPERATURE silicone rubbers are much more prone to heat damage than the harder black vulcanised rubbers.
TOXICITY for items that are to be handled particularly by children or for applications involving food or drink it is essential to use a lead free alloy.
DETAIL & FINISH - bright polish can be best achieved by pewter some of the higher tin whitemetals can be polished but will dull fairly rapidly all our other alloys are suitable to be plated or painted. Where there is little detail in a mould or where quantity is more important than quality the cheaper alloys can be selected.

Most of the leading manufacturers of military models started out at home in their garage so who knows what you could do, good luck.

LEAD FREE GRAVITY CASTING ALLOYS

PEWTER H1 pouring 260-310C (Recommended for casting into rubber moulds)
We developed this pewter to overcome the difficulties of lead free hand casting into rubber. Results approaching those of machine casting are possible in a fairly broad range of casting temperatures ideal if you have no means of temperature control. It lacks strength in thin sections and if this is a problem Pewter S is the only solution. Can be useful for creating metal masters from RTV moulds. Well suited to jewellery.

PEWTER S pouring 270-315C (Select this alloy for all mould materials except rubber)
Suitable for casting into wood, plaster, sand, metal dies etc.
NOTE FOR RUBBER MOULDS select this alloy where H1 is not strong enough, in this situation this composition overcomes many of the difficulties but for best results great attention must be paid to mould design and accurate temperature control of the metal. Complies with BS5140 (broad description) and ABPC.

Still not sure which alloy to select, use the contact link to find e-mail or telephone help.

We also manufacture a large range of alloys suitable for centrifugal casting, lead free solders.

Centrifugal Casting Alloys : Home
Mould making for tin alloys : Tin Alloy Casting Service
Pricing, ordering and other information
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