![]() |
|
|
#2 (permalink) |
|
Senior Member
Join Date: Sep 2007
Posts: 339
Rep Power: 4 ![]() |
Make sure your using the proper investment ratio for copings - and following the manufacturers instructions. That is where I would start first. If your good on that, then it HAS to be between when the wax up's are sprued & removed off the die. Do you invest immediately after you sprue them? Are you spruing them ON the die? I would. Are you being careful when removing the wax-up off the die?
|
|
|
|
|
|
#3 (permalink) |
|
Junior Member
Join Date: Jan 2010
Posts: 3
Rep Power: 0 ![]() |
I'm sorry if I didn't explain my issue more clearly. The copings fit fine after the castings are done. Our problem arises once they are waxed over and pressed in the pressing oven. It is then that some of the copings develop a slight rock.
We have wondered if the metal could be too thin and warping during pressing from the pressure. Any ideas? Is there an ideal thickness for the metal? We try to keep it no thinner than 3/10. |
|
|
|
|
|
#4 (permalink) |
|
Senior Member
Join Date: Mar 2009
Location: Northern California
Posts: 128
Rep Power: 2 ![]() |
are you using Pulse-press-to-metal?
when i experience something similar, it's because an area is too thin and has "bulged" I simply relieve the metal and 99% that takes care of it. I'm using JP-1, and try to keep metal .2-.3mm. hope that helps carol |
|
|
|
|
|
#6 (permalink) |
|
Senior Member
Join Date: Sep 2007
Posts: 339
Rep Power: 4 ![]() |
I follow you now - your doing press-to-metal. Something you may want to be absolutely certain that you are doing is when your waxing, to wax a short "tang" or "fish hook" or "T-bar" on the lingual side of the coping to prevent the copings from shifting in the investment while being pressed. There is alot of pressure coming down during the pressing process. These little stabilizers lock the coping in the investment and prevent any movement during processing.
As stated in an earlier post is making sure you are keeping true to the manufacturers recommendations on minimal metal thicknesses to prevent bulging or deformation. Generally, higher gold content alloys have to be a little thicker than semi-precious ones. |
|
|
|
![]() |
| Bookmarks |
| Thread Tools | |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Emax pressed over white gold greening | neila | All Porcelain-Press | 2 | 10-20-2009 11:18 PM |
| Micro-CT Evaluation of the Marginal Fit of Different In-Ceram Alumina Copings | Travis | Dental News | 0 | 08-27-2009 06:33 AM |
| 10 copings $.99 on ebay so far | DMC | To buy, for sale | 0 | 08-12-2009 03:29 PM |
| Casting plastic implant copings issue | Pronto | Implants | 12 | 02-27-2009 09:49 AM |
| Crown fell and gum pain when pressed | Travis | Dental News | 0 | 05-10-2008 06:40 AM |