Casting Brass

[Artie]

I know that there are a few casters of molten metal out there. I have a question....

Im using the standard green sand mix that is often mentioned on line. Im NOT getting the surface finish that I would like (we are talking casting brass here)

Is there a secret that I havent encountered?

Am I doing something wrong?

Ive cast aluminium for years but only just started casting brass and while im getting ok results (particularly in Ali, brass is rough) I want better. See attached pics for example.... how do I achieve the finish in pic 2 when I am currently producing pic 1?

Is this a need to use lost wax investment casting? looking at the parting line in pic 2 I dont think it is investment cast. Do you agree?

 

[Groomengineering]

Hi Artie, it's probably shell cast http://www.custompartnet.com/wu/shell-mold-casting. Haven't done much research on it but I think it's beyond the scope of home casters. I haven't cast brass (yet...) but I've had very good luck with aluminum in petrobond.

Jeff

 

[Artie]

Gday Jeff, ive use the oiled sand before and it is good but tends to be a little messy (stains etc). Ive also heard of using it around the plug as a barrier from the molten metal to the moist green sand. Might give that a go next time... also looking at plaster casting... will try this over the next coupel of weeks as well...

Cheers

Rob