dumb partial casting question

[erinspeed]

I was casting this wknd, and one of my partials miscast by blowing metal out the side of the investment. One of those fireworks shows that makes you jump back away from the casting machine. I figured it was junk and threw it in a sink of cold water so I could figure out who I need to get making a new refractory model for. After casting the rest of the uneventful batch, I broke the investment off the now cold frame. To my surprise, it cast just FINE!! The sprue stopped where the hole in the investment was, but all rests, clasps, connectors, etc. were there.

Question of the day:
Did I screw this partial up? Is it ruined on a crystalline scale? Is the metal now brittle? I know the mfr says not to quench. Should I just re-cast for the peace of mind?

I'm hoping some of the gurus here have an answer.

P.S. Bego Wironit w/ induction casting machine.
P.P.S. Duplicate post in the "metal" category

 

[altlab]

Partial blowouts and how to end them totally

Suggestion I have used with 100% success: Go to the hardware store and buy a roll of 1/4" hole galvanized STEEL hardware cloth (wire mesh)such as covers gutters and cut a length smaller in height than your ring. Overlap.Sides only - bottom not necessary. Wire the ends together in a few places. Distance from walls no big deal. Some better than none but either works.

Invest. Works with ring or ringless (I use tapered ringless).Does not affect expansion (trust me) but prevents small cracks from growing. Bottom wire has not been needed. Cracks tend to go down the sides.Wire stops them from traveling. They don't like to go throught the refractory model in the bottom.

Also with this technique you can use 24 degrees per min straight up with a hour hold no matter how many rings.No stepped rise. No more pampering the investment to behave. I use Bego's Wiroplus S but it WILL self-destruct without the wire....and every other investment I have used at this speed.Minor fins sometime...of no consequence.

When it cools you will see all kinds of cracks - ignore. You will also see the wire show through in places - ignore some more.

When you devest grab the wire at the overlap and twist and it will totally peel off in one piece. Devest normally.

Reminder:
Get STEEL wire mesh - not aluminum (melts). Test it with a magnet and don't guess. Melted aluminum is no fun.
No smaller than 1/4" square holes - any smaller and the thick investment won't go through it dependably...this means no tiny expanded metal (tried it).
Stop short of the top of ring or the wire tips will annoy you - but they just bend/burnish over with a spoon if you forget.
Unrelated: If anyone has any Dentsply Success equipment for sale I'm interested.Hard acrylic not the thermoplastic system.Now to figure out the classified post... [email protected]