Hi… Take look at bronze casting on YouTube in particular there's a guy under the pseudonym of Doubleboost. He's made loads of useful video clips on all sorts of machining and engineering topics. Well worth a look.

John 

Sorry I wasted my time mentioning it…

It is maybe the calcium in the milk that acts as a chellate? I remember the spray painters getting a pint of free milk a day but not the workers close by who were also getting affected by the vapors from the paint.

Clive

There is a man by the name of Knolle Shelley who is an excellent brass caster and gives a very interesting talk/demo. I know he has been to several model engineering clubs in the south of England including some more than once. A couple of years ago I went to his talk at Chingford Model Engineering Club by invitation of a member who is a friend (thanks again Gordon!)

Basically, he does not add any zinc and does not fear the fumes…..he controls temp very accurately using a thermocouple and pours at 1070 degrees…….failure to do so risks a 'shunt', a fault in the cast due to the metal cooling as it pours…….heats using propane………allows for the slight shrinkage when making the patterns…….uses Bentonite enriched sand……..makes lots of bits for the traction engine fraternity which come out f the sand needing little or no finishing………he had a beautiful name plaque about 18 inches long from a traction engine where the owners only had the one side and he used this as the pattern for the replacement one for the other side…….quality was superb although he demonstrated that shrinkage meant the new plaque was actually slightly smaller than the original.

Edited By Bob Stevenson on 26/01/2016 01:14:09

Btw. There exists kits for casting (brass) using a microware oven ..basically lost wax investment casting with special slip that creates the “crucible”

How's this for high-tech. Ian S C

Neil, yep.

Found these a while back when a thread on Sterioscopes came up, andI had a look through my box of photos from early last century.

Ian S C