"Reaction Layer" e.max

[2th4u]

Any tips or tricks to minimize the reaction layer on e.max pressable units? Also, the Invex liquid is ineffective even after 20 min. in the ultrasonic. Is there a combination of aluminous oxide blasting and etching acid that works better?

 

[Mark Jackson]

Any tips or tricks to minimize the reaction layer on e.max pressable units? Also, the Invex liquid is ineffective even after 20 min. in the ultrasonic. Is there a combination of aluminous oxide blasting and etching acid that works better?

8 minutes (corrected-480 seconds) in WARM invex liquid. Also use hot tap water in ultrasonic bath. Change Invex liquid every day. Sandblast at 15 degree angle to "peel off" reaction layer.

 

[2th4u]

Thanks. Just switching from Finesse All-Ceramic for our pressables to e.max. I notice that the e.max surface seems to be slightly "orange peel" in surface texture (microscopically),in contrast to Finesse which pressed accurately and with a smoother surface.

 

[user name]

Have you played with different temps to minimize the reaction layer? The Invex liquid doesnt remove it. It just weakens it so it can be blasted off. With everything dialed in correct, there wont hardly be a need for more than 5 minutes in the Invex.

 

[2th4u]

Have only begun pressing e.max, nothing yet for actual production. Obeying the Directions For Use exclusively right now. Are you suggesting to raise or lower the temps from the published values?

 

[andycwdt]

I have found that when using the ivoclar pressing furnace the reaction layer is very thin, but using other types the layer is thick. I dont work for ivolcar by the way lol.

 

[[email protected]]

Just started with emax and followed instructions so had no hassle, the invex doesnt remove the reaction layer, got to blast like Mark says, just turn the pressure down on blaster to between 1 to 2 bar max or margin may get damaged if you are not carefull?, anyway worked perfectly for me, crowns fitted brilliantly.popcorn

 

[Brett Hansen CDT]

I lowered the reccomended temps by 5 degrees on my ep500. It reduced an already slight reaction layer to almost nil and i have had zero misspresses.

 

[NicelyMKV]

Does a lower temp effect translucency?

 

[graeme]

we had this problem until we stuck strictly to putting rings in burn-out furnace at 850ºC (sorry I'm from UK we don't use ºF). Also be careful blasting some blasting grits can effect the shade i.e make them appear grey. Once the come out of the Invex we glass bead the reaction layer off, avoids margin damage as well

 

[Corelab]

I've had this trouble too, so I basically lower the pressing temp by one degree each time I do a pressing ... they've started coming out a lot better, but I still get a bit of reaction layer!

 

[KMoft CDT]

If you're getting the orange peel effect, you've got WAY to much reaction layer (RL). Drop off your press temp 5 degrees. Then monitor and adjust 1 degree after that. You want a very slight RL.
If there's no RL you're almost too cool and headed for mispresses.

 

[Rugardave]

Reaction Layer

We use Microstar HS. Set hold time for 5 min. The shorter the hold time the thinner the layer. We press at anything between 1706 and 1710 F. Layer should blast off during the first devest. If it doesn't use the Acid for 10 min. in sonic and always use fresh. It's good for the first 20 acid cycles.

 

[disturbed]

Does a lower temp effect translucency?

it's sooooo slight Jason.

 

[Markyboy]

If you're getting the orange peel effect, you've got WAY to much reaction layer (RL). Drop off your press temp 5 degrees. Then monitor and adjust 1 degree after that. You want a very slight RL.
If there's no RL you're almost too cool and headed for mispresses.

My furnace was cold pressing at 945 and at 950 was getting the orange peal effect. Try and reducing the pressing time, I reduced from 10min to 8min and am getting a better result. I believe some are even pressing as little as 2min. I may reduce even more.... until I get a bad press.

It takes a while to dial it in, I am not there yet but getting closer.

 

[ps2thtec]

eVestic pixie dust

So I just divested a 200g after using this product I found at Lab Day.
It's suppose to eliminate any need for acid and alox blast.

The reaction layer was about 90% gone with just the first glass bead step.

Mixed tiny scoop with liquid mix and powder, investing as usual.

Should be a real time saver. I'll update after a few more.
Anybody else try this product?

 

[paulg100]

"The reaction layer was about 90% gone with just the first glass bead step."

mm, thats about the same as im getting without using that product i think.

 

[ps2thtec]

eVestic pixie dust Update

Well just divested a couple 100gm .
The pressings had a little reaction layer, more like some dust, not
like I have seen more regularly. There's always something and I
think some appears after the acid? For those that claim no layer
have you ever put in acid to see what you might find?

Hey Paul100, maybe 95% . Is this something only
non IVO ovens give off.
For .20 a ring it probably will save some time. Just thought the layer
Would be totally gone

 

[EJADA]

I think we should get some photos posted showing what we feel is acceptable reaction layers. I think I have some on my network I will post when I'm at the lab and not on IPad

 

[swfldental]

emax reaction layer

just lower burnout temp. we did this and there is very little layer. i also blast with oxide right off the bat. i took a old veneer and blasted it hard with oxide and it took a long time to damage it.