Voids in Emax Press (ep 3000)

[Smilesrus]

recently started having "Voids" in Emax press .....Only Molar crowns, and only in my EP 3000 oven.. I have 2 ep 500s and 3 pro press 100s .. they press everything perfectly so I don't think it is a spruing issue... Anyone else have problems like this with the EP 3000 ??? Of course Ivoclar says it's "spruing" I disagree, but am willing to try anything to get rid of the problem !!

 

[Brett Hansen CDT]

What do you mean by "voids?" We use an EP500 and occasionally I will get small pits, which we are able to fill in with glaze. With or press, I have found that it is very important that the height of the sprue and waxed crown do not exceed 15mm over the top of the ring former.

 

[Smilesrus]

these are Monster Voids.. not small pits.. those I can handle and expect on occasion. very unusual...I increased the burnout time slightly since it is only happening in 200 gram rings .. thinking perhaps it was related to incomplete burnout or "cool" spots in the ring.. hasn't helped ... we are diligent in our spruing and since it doesn't happen in the other 5 presses I think it is a ep3000 issue...

 

[Brett Hansen CDT]

Yeah, I have never encountered that problem.

 

[ZOOMAN]

Temperature or pressure, maybe a press motor problem. I would try temperature 1st.

 

[TheLabGuy]

I wonder if the void isn't investment impregnated into the e.max but once you sandblast it shows up as a void because the investment gets sandblasted away, leaving the void. Why I suggest this, is because I've seen once in a great while where a piece of investment was on the side wall before I placed the ingot and plunger into it after burning out. Just a thought.

 

[ZOOMAN]

Lab Guy, It's possible but then I would worry about the base and also possibly the plungers. emax is more liquid (less viscous) then other ceramics. you would think it flows easier. I think there is a problem with the furnace.

 

[NicelyMKV]

EP 3000 is easy to calibrate if its like the EP 5000. May need to try that.

 

[CatamountRob]

Some photos might be helpful.

 

[charles007]

Ship back to Ivoclar and ask for a free loaner....problem solved.

 

[NicelyMKV]

charles, I was informed recently that after ivoclar did some research on the amount of equipment out on loan they changed their policy. I think i was told the EP5000 was over 600 a month to rent while your machine was being repaired. Apparently when they did the math there was quite a lot of money out on loan. May want to ask them about it.

 

[BobCDT]

Did you check the vacume?
If the voids are spherical than it's probably air trapped in the mold. If the voids are random odd shapes it may be investment. I don't think it's investment because you have narrowed it down to a single press.

 

[Smilesrus]

Thanks for the input ... Had my Ivoclar guy in today.. we set up a "new" program in the Ep3000 with 5 min longer HOLD time... We all pretty much agree that it is a Temp issue .. Not contamination, or vacuum.. If this works , I'll post

 

[charles007]

Thanks for the input ... Had my Ivoclar guy in today.. we set up a "new" program in the Ep3000 with 5 min longer HOLD time... We all pretty much agree that it is a Temp issue .. Not contamination, or vacuum.. If this works , I'll post

If there's nothing wrong with your oven, why would your rep extend the hold time by 5 minutes. When you calibrate, it should work like a charm....
I would send back and ask your rep to drop off his oven......
The way it is now, your going to need to change everytime you install new updates, and maybe when you calibrate again ?
Maybe I'm wrong !! Are you guys with Ivoclar ovens CHANGING the preset setting ? Its been almost 3 years with just calibrating and having 100% success in presssing emax......

Please speak up if others are playing around with these Ivoclar ovens !!!!!!

 

[Smilesrus]

we calibrate regularly (no choice with the Ep3000, as you may know) ... we set up an "individual" program with the increased time,, only for 200 gram rings, HT ingots and Molar crowns .... seems to have cleared up the issue.....