VM9!!! Nightmare

[kimba]

maybe slow your heat rate down too . Let the zr absorb more heat

 

[grantoz]

you need to increase slow heat and slow cool more, the bigger the frame work gets .you have also dried out the job far too quickly Zi is a poor conductor of heat so it will take time.What you have done is an excellent example of why porcelain was chipping off Zi frame works in the early days dont feel bad the vm9 instructions dont cover this very well i would recommend looking up the ZZ site for firing tables and then adjusting for vm9.When i did a study with a group of pros specialists we even contacted vita to check their tables because when we fired large amounts at once we got exactly what you were getting. Vitas response was oh yeh you should cool it slower only solved half the problem .Grind it all off and start again.

 

[adl]

you need to increase slow heat and slow cool more, the bigger the frame work gets .you have also dried out the job far too quickly Zi is a poor conductor of heat so it will take time.What you have done is an excellent example of why porcelain was chipping off Zi frame works in the early days dont feel bad the vm9 instructions dont cover this very well i would recommend looking up the ZZ site for firing tables and then adjusting for vm9.When i did a study with a group of pros specialists we even contacted vita to check their tables because when we fired large amounts at once we got exactly what you were getting. Vitas response was oh yeh you should cool it slower only solved half the problem .Grind it all off and start again.

Great point

 

[TheLabGuy]

VM9 is a fine powder porcelain...Therefore, no way you should be building in one bake like some of the large particle brands of porcelain. Furthermore, do a wash bake in the interproximals, then just a dentin and some internal powders (if used) bake, then another dentin and initial incisal bake, then finish off with your incisal halo's bake and anywhere else is needed. Use the correct build-up liquid, and add 10 mins to your dry time as well. Condensing is easy when you do multiple bakes...and that's the key with fine porcelain powders. Hope this helps.

 

[PinAn]

Thanks guys , all are helpful but I hope can finish this in one day... so is that really can't do one bake?

 

[rkm rdt]

Its too early in the day to keep editing this post.
Go ahead and do the same thing. Maybe it will turn out different the next time.

 

[CatamountRob]

Thanks guys , all are helpful but I hope can finish this in one day... so is that really can't do one bake?

Sometimes one post says all that needs to be said......

 

[rkm rdt]

Sometimes one post says all that needs to be said......

I keep deleting my response .I'm so pissed off right now.

 

[CatamountRob]

I keep deleting my response .I'm so pissed off right now.

Just move on, not all of them can, or should be saved.

 

[rkm rdt]

Just move on, not all of them can, or should be saved.

I feel for the patient.

 

[Bumfrey]

I have to say that i got the feeling this was the first time you are trying to do buildups when i first saw this post and i didn't respond. Its usual to see shrinkage, and the odd split in bridgework if you don't separate the units with a blade. The minimum bakes for a bridge is two. This should be obvious if you have been stacking glass for a while.
opaque FIRE
opaque FIRE
margin FIRE
1st build FIRE
2nd build FIRE
glaze FIRE
Minimum.

 

[Bumfrey]

FIRE = BAKE
just in case.....

 

[PinAn]

Yes man I will do that

Thanks guys the information all are helpful

 

[PinAn]

I feel for the patient.

man I will do what you said
Sorry

 

[adamb4321]

I tried VM 9 a number of years ago, it's not very nice and is prone to lots of tearing. I found it to feel almost "syrupy" when mixed with plain H20.
I never managed to overcome the issues and stopped using it. It was a real shame as the VM7 kit I had for Alumina was excellent and built up and fired beautifully. Some porcelains are just plain awkward to use, or just don't suit everybody. To the OP, don't fight it, bin it, and find a porcelain that does work for you.

 

[rgkbmk]

Slice the inter proximals open with a thin blade. Condense and dry with hairdryer. If you need to add porcleain do a second or 3rd bake

 

[Tayebdental]

He seems to be a tea drinking tech, my friend drink dark coffee and watch your hands do the shake and bake