Noritake EX3 firing parameters

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adamb4321

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I switched to Noritake EX3 maybe 6 months ago, I keep getting a recurring bubble problem that can range from very minor to bloody major.

I've been through all of our processes and tightened up on our sandblasting blasting and opaquing procedures which has helped but not eliminated the problem.

The porcelain looks good when fired with nice clarity/translucency but after glazing has either micro porosity or big surface bubbles, crowns that have had additions are affected the most.

I keep thinking it's under fired and that's what is causing the problem (I've already increased the firing temps about 20'c over the Noritake recommendation) but it looks like its fired properly.

What temps/parameters are you all using (furnace is a Zubler) for Noritake and do you think the suggested firing temp for additions is to low or ok?
 
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First start with your opaque. If you are using the paste opaque, do not mix in the covering oil/liquid. Tilt the jar and use the opaque that is not covered with this liquid, it is only there to maintain the moisture until the opaque is used up.
My temps are in fahrenheit:
Opaque:start 931F, 8 min. dry(ramp up),heat rate 117F, drop vac @1795F, 1796F hi, 1 min hold.
Bake 1: 1111F, 8 min. dry, rate 81F, drop vac. @1665, 1670F hi, no hold.
Bake 2: 1111F, 5 min. dry, rate 81F, drop vac. @1660, 1665F hi, no hold.
Natural Glaze: 1111F, 4 min. dry, rate 81F, no vac. unless adding on, 1645F hi.
I've been using EX3 for years, and these temps/times work for me. Porcelain furnaces will vary in temps, so adjust your temps and times slowly( 5 degrees +/- at a time).
A friend had a similar problem and it came down to the opaque covering liquid. He was mixing it into the paste, Noritake's instructions say otherwise.
 
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Probably a paste opaque problem
low temp 500c or less... 8-9 minute dry.. thin layers, don't try to opaque with only 1 layers.
List the grinding tools your using... No steam cleaner/it can contaminate.
Oxy and propane setting ?
Use clean crucible
 
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Use a base layer of GC In-Metal bond or the Bredent equivalent. Or IPS Classic PO as base layer especially if its Ni/Cr and fire @ 980`C. We have had this question before and a tech PM`d me and said this sorted the problem .
 
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Use a base layer of GC In-Metal bond or the Bredent equivalent. Or IPS Classic PO as base layer especially if its Ni/Cr and fire @ 980`C. We have had this question before and a tech PM`d me and said this sorted the problem .

Probably a paste opaque problem
low temp 500c or less... 8-9 minute dry.. thin layers, don't try to opaque with only 1 layers.
List the grinding tools your using... No steam cleaner/it can contaminate.
Oxy and propane setting ?
Use clean crucible

Non precious is normally ok for us and we use the Bredent paste as the first coat on NP (I still get bubbles if I use it on precious) but the big problem is precious metal (argipal) I've had one today bubbles around the cervical (over porc butt fit) and down the distal contact area. spherical voids, trimmed them out and they didn't go through to the opaque, did a correction in the glaze bubbles gone but now the ceramics cracked. So, I'm thinking the opaque has bubbled/debonded so I trim off all the ceramic and opaque to find no bubbling at all and the opaque is still bonded to the metal surface.

Trimming is done with tungstens, NP I tend to smooth over with a blue stone, precious are also trimmed with tungstens and then smoothed over with a brow stone, all blasted with ALOX 120micron at 2 bar and then steam cleaned.

I've just replaced the crucible etc I'll double check the gas settings but I don't think anything has changed there.

We give the units a thin coat of bredent and the precious a thin coat of duceram kiss (the noritake opaque seems to cause loads of issues when used as the first coat).

And just to add insult to injury my colleague with 2yrs experience isn't getting this issue (she mainly builds up on the np units) I fired my work with hers today, her units all ok, mine were bubbly bullpoop.

If I use the cercon kiss on zr I have no issues at all, I've never seen a problem like this with no obvious cause and I cant think of anything that I'm doing that would promote bubbles.

it's a real pain, i'm going to get my colleague to re build the one that bubbled, so if it does it to her
 
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rkm rdt

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I never use stones on precious alloys!!! You are folding the soft alloy and creating air pockets in the opaque.

and I never use carbides on semi ,only white aluminum oxide stones.
 
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adamb4321

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I'd agree if it was a softer, high gold content alloy and if I was using a lot of pressure when trimming but on the high Pd alloys I don't think folding takes place, I've only used the stones fairly recently but the issue was there before. Also the bubbling today isn't coming from the metal surface or through the opaque it's just in the ceramic. Which makes me think underfired or poor vacuum, or something i'm doing.
 
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adamb4321

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First start with your opaque. If you are using the paste opaque, do not mix in the covering oil/liquid. Tilt the jar and use the opaque that is not covered with this liquid, it is only there to maintain the moisture until the opaque is used up.
My temps are in fahrenheit:
Opaque:start 931F, 8 min. dry(ramp up),heat rate 117F, drop vac @1795F, 1796F hi, 1 min hold.
Bake 1: 1111F, 8 min. dry, rate 81F, drop vac. @1665, 1670F hi, no hold.
Bake 2: 1111F, 5 min. dry, rate 81F, drop vac. @1660, 1665F hi, no hold.
Natural Glaze: 1111F, 4 min. dry, rate 81F, no vac. unless adding on, 1645F hi.
I've been using EX3 for years, and these temps/times work for me. Porcelain furnaces will vary in temps, so adjust your temps and times slowly( 5 degrees +/- at a time).
A friend had a similar problem and it came down to the opaque covering liquid. He was mixing it into the paste, Noritake's instructions say otherwise.

Thanks for the firing temps, we were already aware of the not mixing the oil in, we tend to pour it off when a new jar is opened.

Just out of interest which furnace are you using?
 
ICONDENTAL

ICONDENTAL

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I switched to Noritake EX3 maybe 6 months ago, I keep getting a recurring bubble problem that can range from very minor to bloody major.

I've been through all of our processes and tightened up on our sandblasting blasting and opaquing procedures which has helped but not eliminated the problem.

The porcelain looks good when fired with nice clarity/translucency but after glazing has either micro porosity or big surface bubbles, crowns that have had additions are affected the most.

I keep thinking it's under fired and that's what is causing the problem (I've already increased the firing temps about 20'c over the Noritake recommendation) but it looks like its fired properly.

What temps/parameters are you all using (furnace is a Zubler) for Noritake and do you think the suggested firing temp for additions is to low or ok?[/qu

" ARGIPAL" IS NOT RECOMENDED TO USE WITH NORITAKE THEIR C.T.E. ARE NOT COMPARABLE , ARGELITE 76 SF+ IS RECOMEMDED.
 
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mmm, Ok I don't think they even sell Argelite 76SF+ in the uk, I've looked for the CTE in the Noritake instructions but cant see it anywhere. Where are you getting your info from?

Argipal CTE 13.9 @ 500'c 14.1 @ 600'c

Argelite 76SF+ 14.1 @ 500'c 14.3 @ 600'C

The NP Alloy we use 14.1 @ 500'C (we use with no issues with Noritake)

I've just ordered some Argelite 80SF+ see how that goes.

Anyway, wouldn't CTE issues cause cracks not bubbles?
 
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So, I got my young colleague to re-opaque and re build todays crown that bubbled and cracked.

She did two opaque firings, two margin firings, one dentine/enamel build up and one glaze firing, and it came out absolutely perfect.

Must be something I'm doing, just don't know what.
 
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I had the exact problems like you but i work only on NP alloys , i tried like 30 different stuff and i still i had those bubbles , i wont tell you all what i used because everything didnot help but two things i did last try then it solved the problem , first on my NP alloys i started to use 3c bond as first opaque wash and second opaque i do it with vision powders , this on 3 types of NP alloys i had in lab and all worked fine without bubbles , meanwhile i ordered Talladium alloy which is tlite and 3c bond do not work on it because it contains titanium , so on taladium alloy i use wash opaque vision powder and second opaque vision powder and 100% result , so far this 2 methods are giving me beautiful noritake without bubbles , hope this helps.
 
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So, I got my young colleague to re-opaque and re build todays crown that bubbled and cracked.

She did two opaque firings, two margin firings, one dentine/enamel build up and one glaze firing, and it came out absolutely perfect.

Must be something I'm doing, just don't know what.

Possibly is your brush contaminated from a porc seperator .

Mentioned this issue to friend that uses EX3. Says he had the problem and traced it to that after having Bubbles after adding to a Pontic and the next crown andpontic both had bubbles to the opaque.
Maybe have your colleague stack crown with your brush. And your sponge too?
 
ICONDENTAL

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mmm, Ok I don't think they even sell Argelite 76SF+ in the uk, I've looked for the CTE in the Noritake instructions but cant see it anywhere. Where are you getting your info from?

Argipal CTE 13.9 @ 500'c 14.1 @ 600'c

Argelite 76SF+ 14.1 @ 500'c 14.3 @ 600'C

The NP Alloy we use 14.1 @ 500'C (we use with no issues with Noritake)

I've just ordered some Argelite 80SF+ see how that goes.

Anyway, wouldn't CTE issues cause cracks not bubbles?

Didn't go into details because you have fractures . also did not know you are in the UK very sorry, but if you only were having bubbles I will go into your degassing what is your high temperature? do you hold at high temp.? and for how long? do you remove the oxide after degassing? , the least will go away are your fractures, If you use a comparable CTE alloy. and Argipal CTE is not comparable with Noritake.the information is from the main Mother of knowledge Argen.com Hope it helps.
 
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RDA

RDA

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Thanks for the firing temps, we were already aware of the not mixing the oil in, we tend to pour it off when a new jar is opened.

Just out of interest which furnace are you using?
I have four different ones, Jelrus Wizard, Shenpaz Focus, Image Press/combo, and a Ney Cerampress/combo. I fire Noritake in all of them with good results.
 
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Didn't go into details because you have fractures . also did not know you are in the UK very sorry, but if you only were having bubbles I will go into your degassing what is your high temperature? do you hold at high temp.? and for how long? do you remove the oxide after degassing? , the least will go away are your fractures, If you use a comparable CTE alloy. and Argipal CTE is not comparable with Noritake.the information is from the main Mother of knowledge Argen.com Hope it helps.
Hi Icon,

we oxidise at 980'c for 5 mins in air and then re-sandblast. We don't usually get tension cracks, however, sometimes there are cracks that are being caused by the bubbles in the porcelain.

I got my colleague to build up another Argipal bridge today, and again she had no problems. I spoke to the UK argen supplier who told me that Argipal is ok to use with Noritake but I wouldn't like to swear that they are right. There seems to be no info in the Noritake instructions as to the cte range of the ceramic which unusual.

Today I'm casting with a new crucible and Argilte 80SF+
 
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adamb4321

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Possibly is your brush contaminated from a porc seperator .

Mentioned this issue to friend that uses EX3. Says he had the problem and traced it to that after having Bubbles after adding to a Pontic and the next crown andpontic both had bubbles to the opaque.
Maybe have your colleague stack crown with your brush. And your sponge too?

I have to say the bubbles look like they are from some sort of contamination, I don't use a sponge to we can rule that out. But a lot of the units I build up do have porcelain margins, maybe the porcelain separator is causing the problem.
 
technician

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I have to say the bubbles look like they are from some sort of contamination, I don't use a sponge to we can rule that out. But a lot of the units I build up do have porcelain margins, maybe the porcelain separator is causing the problem.

If theres a bubble going all the way down to the opaque and theres a small black dot in the bubble then its the metal causing the problem. If the bubble is just in the porcelain layer then I think as you say the porcelain is contaminated. Do you have your own set of porcelain or do you guys use the same? If not maybe it's your porcelain that is contaminated. EX-3 will fire on almost all dental metal on the market.
 
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Hi, we did have an issue with bubbles coming through the opaque which we've sorted.
My bubbles are just in the ceramic, we both use the same porcelain set so I don't think it's anything in the powder that's causing the problem otherwise we'd both have bubbles.

I've never seen this in 20+yrs, and it's more annoying that it's me its happening too rather than the newbie!
 
ICONDENTAL

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Hi Icon,

we oxidise at 980'c for 5 mins in air and then re-sandblast. We don't usually get tension cracks, however, sometimes there are cracks that are being caused by the bubbles in the porcelain.

I got my colleague to build up another Argipal bridge today, and again she had no problems. I spoke to the UK argen supplier who told me that Argipal is ok to use with Noritake but I wouldn't like to swear that they are right. There seems to be no info in the Noritake instructions as to the cte range of the ceramic which unusual.

Today I'm casting with a new crucible and Argilte 80SF+

this are theparameter for ARGIPAL and for ARGILTE 80SF+
Oxidation Procedure:for ARGIPAL
650-1010°C, hold 5 min, remove oxide

Oxidation Procedure:FOR ARGILITE 80SF+ 650-1010°C, hold 5 min, remove oxide, no vacuum

When you said that your college build another bridge , did she used Noritake?
the fractures come from diferent directions , such as over glazing which will also make your shades not to match 100% one way to fix fractures is to Grind "V" shaped trough along the crack, fill in with porcelain and refire.and the bubbles could be due to Unclean metal , make sure there is no trace of investment and when you clean prior to degassing use distil water and also no air-house it. let us know how is it going and if you could show some pictures of fractures and bubbles so we can have a visual.
 
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