How to make check a mold..

[ROCKET]

I'm trying to buy some used Noe moulds from someone who doesn't cast anymore. How do I make sure the molds are still "ok" ?

Anything in particular I should look for?

[Bent Ramrod]

Look for deep scrapes or galling on the top face. Look for burrs or battering around the holes the alignment pins go into. Make sure you can't see strong light between mould halves when it is closed. Look for burrs, displaced metal, nicks, whatever, on the edges of the mould cavity. Check the sprue plate for warpage or battering. Check for bad pitting in the cavity. Surface rust usually doesn't matter, nor do pits on the outside, except to look ugly and drive the price down.

Aluminum moulds are prone to battering, scratching and galling; brass to scratching and perhaps warpage (never seen this myself), and iron to rusting.

If you could cast a few and check them that way, that would be best. Can you get a few days' trial before buying?

All this said, many faults in many a mould can be corrected and a somewhat abused or neglected mould can be brought back to good service by a decent home mechanic. The price then becomes the factor for salability.