Cracks in the investment

[KentPWalton]

How long are you burning the rings out before you put them in the press? We burn out 200g rings for 1hr 15 mins and have no problems. COLD AlOx plunger and ingot. Open the oven, then use a pair of big tweezers to drop the ingot and plunger in the ring right before we put them in the furnace, then start the program. Shouldn't have any problems. You have to make sure the plungers are completely clean. Glass bead them off first then use Alumina Oxide to clean them really good. If you have any questions, call your Ivoclar rep and request the instructions from them and read over them twice before you proceed any further. Millions of R & D money spent on figuring out this product, so follow their protocol. It's really easy once you get all the steps down. Happy Pressing!

 

[ps2thtec]

No. Cracks have appeared a few seconds after entering and closed with the EP3000 press program. I heard a tick after about 20 seconds.

So, you're hearing cracks or seeing cracks?

The only scraping needed on the press ring is the nub from the leveling cap. Then put in the burnout. Risk of changing the vertical of the ring.

 

[KentPWalton]

So, you're hearing cracks or seeing cracks?

The only scraping needed on the press ring is the nub from the leveling cap. Then put in the burnout. Risk of changing the vertical of the ring.

I agree. You don't need to scrape it down a ton. Just enough to get rid of the "nub" and make sure it's level for the plunger to go in properly. If it's at the wrong angle, the plunger and press and break/crack the ring or press out the side of the ring. I only know this from experience.

 

[NathanNever]

Before I heard them, then when finished the program I've seen. I followed the instructions precisely, with the test kit that was given to me by the rep.: No problem. Cracks have appeared with the new package of PressVEST speed (trial set of 2 bags).

 

[KentPWalton]

The cracks are from the first post? I don't see a problem with them. They will not effect your pressed units. They will hairline crack like that from time to time. We have some just like that first picture you posted and haven't had problems with them. I don't know if I would worry about those small guys like that at all!

 

[NathanNever]

Indeed, the work came out well anyway. it's just strange that it repeats, two on two. Next week I have a new case, we see how it goes, of course are only limited cracks.

 

[KentPWalton]

Let me know how it turns out!

 

[NathanNever]

for sure. Thanks again. I'm new with e.max, are my first crowns, but I'm having fun as a kid, with the new game.

 

[EJADA]

If these hairline cracks are not effecting the units what is the worry?

DON'T WORRY, BE HAPPY. As the song goes.

These cracks are normal. I get them in my gold casting rings as they cool also. ( microstar HS)

 

[KentPWalton]

If these hairline cracks are not effecting the units what is the worry?

DON'T WORRY, BE HAPPY. As the song goes.

These cracks are normal. I get them in my gold casting rings as they cool also. ( microstar HS)

Same here. We're using the same investment. It's good stuff!

 

[user name]

In 20 seconds you havent reached the high temp, so the press hasnt started. I dont know what youre hearing, but its not the investment cracking. The cracks in your pic are typical with my results. I believe they (mine) result during cooling.

 

[KentPWalton]

In 20 seconds you havent reached the high temp, so the press hasnt started. I dont know what youre hearing, but its not the investment cracking. The cracks in your pic are typical with my results. I believe they (mine) result during cooling.

I agree. Ours happens when the table comes down with the ring and it starts to cool. At least that's what the directions say on Emax.

 

[NathanNever]

Let me know how it turns out!

everything went well! No crack, less reaction layer, also because I have lowered the temperature of burnout and also the temperature of pressing.

 

[kiter73]

I have those cracks and than when i divesting i can see the ingot material pressed in the cracks .They go away with sandblasting but leave discoloration shade difference on the crown.Do i have temp too high.Tell the truth i did not scrape the last couple ring and i still new to the emax.Still playing with the settings and temp.