Opaque bubbling questions...

[BruceQuality]

I posted this over in the porcelain forum, then thought it might fit here too, so sorry ahead of time for duplication.

We are experiencing a problem with our Finesse paste opaques (just a few) bubbling when a porcelain shoulder is being added to the opaqued coping on EDITED, Silhouette Line, 250 SL, (74.78% Palladium.) Has anybody else experienced this? Did you find a remedy if so?

The shades we are experiencing this with are: A0, A2, A3, A4, B1, C1 and D4.

Our opaguing technician worked in another lab a few years ago and experienced the same difficulty with their silver palladium (different metal than ours.) So we now know that this is not an isolated issue and it began before she arrived, so it is not isolated to any individual in the lab either.

Thanks for any/all input!

 

[zena]

We do two layers of opaque. During the first layer will make sure to have an 80 % coverage, I place my honey comb tray on a coffee warmer plate which I have plugged in on my bench for this purpose only "I swear" to let my copings dry, before I put it in the furnace. I make sure I'm not putting it directly in hot furnace in which someone just came out of, because this burst of hot heat causes cracking in the opaque. Always make sure your opaque is dry not wet or to thick when it's going in the furnace. I hold the crown with the hemostats as I opaque, and once my first layer is on I tap on the hemostats slightly to vibrate the wet opaque and then set in on the honey comb tray which is already on my coffee warmer and let it dry takes a couple minutes. For my second layer I do the same. If I were to see cracks I would not opaque over that cause that would cause a weak base for the porcelain to sit on. I would sandblast off the lifted opaque areas and re opaque. Also make sure you start off with clean metal and avoid touching with your hands because the oils on our fingers could contaminate the metal.

 

[TheLabGuy]

Problem is the silver.......you can sandblast before and after degassing to see if it helps....make sure your opaquer isn't making it too runny (where it runs down to the margine) or too thick layers (trapping air). If your using Finesse (Dentsply),try some Ivoclar inline.......much better porcelain, much easier to use in a production setting.

 

[Al.]

I used W forever and had 0 bubbling problems.
I recently switched to Evolution lite and started getting bubbles during either my porc shoulder bake or when I had to do extra bakes on bridges. The bubbles were all the way to the metal.

I increased the temp on my 1st opaque bake till it came out shiney instead of matte. Basicialy a bond bake. It took a 40 degrees F temp increase.
The problem is solved. 0 bubbles now for me.
Al

 

[BruceQuality]

Thanks for the ideas so far! I did edit my original post as I had the incorrect metal, it is our Semi Precious and it was her old lab's silver palladium, so it is two different metals with this opaque. Our metal is Silhouette Line's 250 SL with almost 75% Palladium and no silver.

Also, this only happens during the shoulder bake, not when the opaque is applied the first time.

Thanks!

 

[BruceQuality]

I've updated the thread in the Porcelain forum rather than continuing it here as well...

Thanks!