Noritake ex3 paste opaque issue

[Edy]

I am seeing lately when i am starting to build more and more crowns using ex3 porcelain that i am struggling with the opaque quait a bit , my noritake supplier tell me that i should get from the small bottle the amount of opaque needed for the crowns i got that moment , inside the bottle u get the paste opaque and on top of it a bit of opaque liquid , he says that i need to incline a bit the bottle so i can get the opaque which is liquid free , and to apply that on crown , not only its too thick to stick the brush in it , but any instrument i tried on it its still was too thick to apply .So i got a bit of the liquid from the bottle to dilute a bit , now its ok to use , i do apply it , i put it in oven at right temp , and always i get areas where the metal is showing a bit of black and other areas i get this small holes in it like the picture i post . I yes do first wash not with the paste opaque but with 3c bonder then i apply the paste opaque as a regular second opaque to mask the metal.



Notice at the lower 3 crowns how u can see the black , and on the upper 3 crowns u see the hole in the mid and interprox , i get this stuff at each work where i am forced to mask just before i add dentin porcelain.

Am i using incorrectly the paste ? my opaque brush is always dry , i never dip it in water like its specified , using the paste like noritake presents without any liquid mixing it comes out too thick to handle , but when i mix with a bit of op liquid it becomes pretty nice to handle but leaves me with these problems , small holes and areas that remain black , and i really hope i should not need to do a third opaque to mask it , and i hope i am doing something wrong here that it can be fixed .

 

[martintay]

Edy always mix the paste opaque , don`t tip the liquid out mix it in. It always separates after time ( as you will see when its new) Also dilute as needed with the EX3 opaque liquid. Increase the dry time and decrease the heat rate until this stops happening. I use low temp of 400C , dry time 6 mins , heat rate 80c/ min but all furnaces are different ! The consistancy is the main thing.... Not to viscous (thick) and not to liquid (thin) Hope this helps.I think your cracking is where the opaque is a little bit pooled (thick)

 

[Tayebdental]

I agree with Martintay, I have been using the Noritake ex3 porcelain for seventeen years, I love it. Make sure after sand blasting the metal is very clean and no microscopic traces of investment on the surface and clean the metal framework in a small glass covered jar 1/3 full with acetone for ten minutes in an ultrasonic cleaner before degassing to eliminate oil on the surface (make sure the acetone is completely evaporated on the metal framework before you place it in the furnace it is flammable),good luck.

 

[desertfox384]

I had issues with the opaque as well.. Like they said above, do a long cool time, start it at a lower temp than the book calls for. I would have problems if I mixed the oil in the jar with the opaque.. it would cause cracks in my opaque.. so I started using an opaque tray (stain tray) and mixing the opaque with the EX3 opaque liquid, no problems since.

 

[Tayebdental]

I had issues with the opaque as well.. Like they said above, do a long cool time, start it at a lower temp than the book calls for. I would have problems if I mixed the oil in the jar with the opaque.. it would cause cracks in my opaque.. so I started using an opaque tray (stain tray) and mixing the opaque with the EX3 opaque liquid, no problems since.

I do not understand what you mean by "mixing the oil in the jar" as we all know this is a thick opaque liquid and not the dreadful oil that cause contamination we all try to avoid. I hope it is a mistake!!!

 

[desertfox384]

No, the oil in the jar IS NOT MEANT TO BE MIXED INTO THE OPAQUE as the book states.. the oil is in the jar to only cover the opaque and keep it from drying out. You are supposed to tilt the jar so the oil runs to the bottom, scoop out some opaque from the top part of the jar where there is no oil and then mix the opaque with the EX3 Opaque liquid.. Yes it is very thick, you need to buy some of the EX3 opaque liquid and mix the opaque with that, not the oil from the jar.

 

[martintay]

I`ve always mixed in the oil from a new jar with no probems , and dilute if needed with opaque liquid.

 

[Tayebdental]

I always use the opaque right out of the jar after mixing it with liquid with no problems, it it true the opaqued framework is a bit dull after firing even at a higher temp. one thing else I build up the ex3 porcelain the dry porcelain technique, it is faster better with no porcelain waste, right out of the bottle.
Good luck to all!!

 

[rkm rdt]

That's not oil!

Mix the paste with the liquid to get a creamy consistency.That's why they call it paste!

Instead of using a brush,try using a glass or plastic instrument when applying the paste.

We actually sandblast the copings and apply one coat of paste. (17 years) without any problems.

Make sure it is dry before firing ,idle a 400c

 

[Tayebdental]

Paste opaque liquid made of organic liquids that are used in the method of paste opaque blending is selected from the glycerols, glycols, derivatives thereof, or dimethylsulfoxide, particularly preferred as glycerol, THAT IS NOT OIL.

 

[Gene]

pre dry on a hot plate

 

[Edy]

I do hope thats not oil because i always mix a bit of it to the very thick paste i scoop out of bottle
Anyhow i stil got my awsome vision opaque powders , i asked few techs who work with noritake porcelain ...many are using vision opaques with ex3 ..getting strong bonds , already made some crowns like that and i just get a very fine egg shell looking appearence and all metal covered pretty good , problem is the shade is too chromatic