Resin Casting issues

[Bryce Hiller]

Question for the group: We've started 3D printing all of our FCG and PFM substructures. The fit is great, but we've been getting a large number of miscasts with our copings. We're having everything printed at Argen and we use WhipMix Hi-Temp investment. cycle is up to 800 at 15 degree heat rise per minute, hold at 800 for 30 minutes, full heat rise to 1600 and hold for 1 hour.

Any ideas what we need to change? Thanks a bunch!

 

[2thm8kr]

Got any photos of the miscasts?

 

[CatamountRob]

What sort of problems and what alloy are you casting?

 

[Bryce Hiller]

We are casting Argelite 54B, here's a shot of the kinds of miscasts we're getting. Large holes in random places, even where there is a 1+ mm thickness.

 

[CatamountRob]

It looks like your alloy isn't hot enough. How thick are the copings?

 

[CoolHandLuke]

seems like you arent getting them all burned out. resin tends to be sticky too, so too low temp, or not enough hold time can make the investment sticky. that, or the alloy isnt getting hot enough to be fluid enough for the mould.

 

[2thm8kr]

Incomplete burnout

 

[CatamountRob]

seems like you arent getting them all burned out. resin tends to be sticky too, so too low temp, or not enough hold time can make the investment sticky. that, or the alloy isnt getting hot enough to be fluid enough for the mould.

An hour at 1600 isn't going to leave much unburned. I've never burned anything out higher than 1450.

 

[CoolHandLuke]

we've had to raise temp and hold when processing cast partials tho. 1700 for 2+hrs

 

[Bryce Hiller]

It looks like your alloy isn't hot enough. How thick are the copings?

Thickness varies. The one pictured had holes in places that were more than a millimeter thick.

 

[Bryce Hiller]

We will try holding longer at 1600. Could it be the investment. or is the WhipMix Hi-temp fine for resin?

 

[CoolHandLuke]

well, lets have whipmix answer: @capickettcdt @Cory@WhipMix

 

[CatamountRob]

well, lets have whipmix answer: @capickettcdt @Cory@WhipMix

Enough of that foolishness. If he wanted a real answer he would've called Whipmix or Argen......

 

[CoolHandLuke]

 

[JMN]

too cold metal
too cold investment
too short burnout
insufficient air escape path at the non-metal-entry end (is it still slightly glazed? shouldn't be)
Too thin
sprue too small and coping is back feeding to fill thicker areas as it cools?

That's just about all it could be


Unless it's NP. Then overheating will cause weird issues too.

 

[Bryce Hiller]

Enough of that foolishness. If he wanted a real answer he would've called Whipmix or Argen......

I can assure you, I've tried...

 

[2thm8kr]

I can assure you, I've tried...

So you're saying we are your third choice?

 

[Bryce Hiller]

So you're saying we are your third choice?

Don't be mad. I'm new

 

[2thm8kr]

Don't be mad. I'm new

Not mad, just curious.

 

[Juko]

We are casting Argelite 54B, here's a shot of the kinds of miscasts we're getting. Large holes in random places, even where there is a 1+ mm thickness.

The edges appear rounded signaling alloy not hot enough at casting. IMO

I've heard lectors state that with resin you should burnout your rings at an angle or even lying on its side as the soot from the resin burn can get trapped inside the ring causing miscasts.