stone and metal

[Bill Smith <besmith@zzzzzzzzzzzzzz>]

http://www.mcp-group.com/alloys/lmpa_proof.html
*The range of MCP low melting-point alloys includes formulations
particularly suitable for proof casting.*

*MCP Quality*

The alloys are produced from high-grade constituents, following strict
specifications. Quality is monitored by an accredited system conforming
to ISO 9002.

*
Stability*

The alloy compositions remain stable for long periods of repetitive use.
With proper attention to correct usage, MCP low melting-point alloys can
be re-used continually over periods extending into years. The specially
designed *MCP melting pots*
< http://www.mcp-group.com/alloys/lmpa_melttank.html  > are recommended.

If the alloy composition is found to have drifted away from the original
specification, it can usually be corrected in-house by the user. For
this purpose, a testing service is available at the Wellingborough
production laboratory.

*
Alloy Features*

A prime feature of each of the recommended alloys is the low temperature
at which it can be poured: this combines with low specific heat and
latent heat of fusion to make it possible to cast against many
containing materials without causing undue thermal expansion or
distortion. The viscosity and surface tension are also low, making for
accurate penetration of the pattern. The volume changes, both during and
after solidification, are very small, ensuring accurate, full size
reproduction. With no shrinkage, hammering-in is unnecessary.

It is usually possible to use the alloys at several stages of
manufacture. Half-casts can be taken quickly and easily, even from dies
with irregular split-lines, and the flash and gutter can be checked at
this stage.

*Choice of Alloy*

Alloy
Designation

Melting
Point

Indications For Use
MCP 47

47°C / 117°F
	Used when low temperature is of greatestimportance.
MCP 124

125°C / 227°F
	The simplest choice. Can usually be poured into a cold die.
MCP 150

135-170°C
275-338°F
	Used for the highest accuracy, preferably with a pre-warmed die.

*Safety & The Environment*
The recommended alloys are not classified as 'dangerous' for either
carriage or supply. They are easy to handle, and quite safe when the
rules for normal handling are observed.

*Melting Equipment*
For use in conjunction with the alloys, MCP offer a range of *Melting
Pots* < http://www.mcp-group.com/alloys/lmpa_melttank.html  > with capacity
for 10, 30 or 60kg of alloy, designed for the melting, dispensing and
recovery of low melting-point alloys, available from stock. With alloy
densities on the order of 9.8kg/1, capacities are about 1, 3 or 6 litres.