I recommend using TUV investment from Zantech. This is "high-speed"
(HS) investment that is very dense and helps produce beautiful
castings with no hassle. I've used other HS investment in the past,
and this one is the most reliable. Zantech can be reached at
Matt Feliksa President Golden Sun MFG., Inc. "Specializing in platinum
casting to the trade." www.goldensunmfg.com