C&B Investment problems

RDA

RDA

Well-Known Member
Full Member
Messages
942
Reaction score
192
Overnight is unusable, I use only fast burnout and ringless. The problem, it does not sat completely in the ring. To the point it sometimes is so soft I could not even remove it from the ring without braking it! Have not tried Microstar HS. I heard mix reviews about it.

I have used Fujivest II for years with a fast burnout. We let it set for twenty minutes minimum before placing in the furnace, and it works out great.

I also use it for at least 15 years. Very inexpensive and good when it is working.... I am one man lab, and always use timer, I also weigh it on the electronic scales, the bags are always have more than 90 grams by few grams. Have You switched to something else? I use 45SF alloy 45 gold 45 palladium. But I also use it for all other C&B use. Like gold crowns and custom abutments.
If you are still use UCLA what investment do you use. The problem with FugivestII when I use it for my custom abatements is micro fins and babbles close to base/platgorm of abatement, and the gold would overflow to the platform, especially if it is closer than 1mm to it. I do make sure the platform is wax free. I clean it with GC Resin monomer and alcohol. Nevertheless I still get gold on the platform. Very annoying! I use broken arm casting machine. I make sure I don't over tight it also. I blame the investment at this point.

For cast custom abutments, what cleared up this fins and overcast for me was, venting the wax up at the base close to the interface, and also placing the ring in a pressure pot. The casting comes out very clean with a full cast to the base with this method.
 
C

charles007

Well-Known Member
Full Member
Messages
3,897
Reaction score
453
Microstar HS.... used it forever with many alloys, both ceramic and c&b without problem...
 
S

stanleyn

Member
Full Member
Messages
53
Reaction score
1
I have used Fujivest II for years with a fast burnout. We let it set for twenty minutes minimum before placing in the furnace, and it works out great.



For cast custom abutments, what cleared up this fins and overcast for me was, venting the wax up at the base close to the interface, and also placing the ring in a pressure pot. The casting comes out very clean with a full cast to the base with this method.
Thanks. I started to bench set for 20min. but now I increased it to 27min.to make it stronger. Still sometimes it's not working. Hate to walk away after 15 years.
I also put went sprues close to the interface of the abutment.
You also mentioned, You place the ring in the pressure pot? I don't have one, where would you get it, and is it worth it? or just easier to replace investment in your opinion?
 
P

Presswood

Member
Full Member
Messages
17
Reaction score
5
They still make beauty cast... isn't that from the 60s.

Maybe the 60's; it was the first investment Whip Mix made.
I've been using it since mid 70's & still about half of my work is FGC's ,cast with Beauty cast!
For pressing & high temp. Metal casting,
Microstar rules.
 
A

adl

Active Member
Full Member
Messages
454
Reaction score
66
I use AP investment for everything. Quick and overnight burn outs emax and whatever little casting I do anymore. It works really well and the price is right as well
 
RDA

RDA

Well-Known Member
Full Member
Messages
942
Reaction score
192
Thanks. I started to bench set for 20min. but now I increased it to 27min.to make it stronger. Still sometimes it's not working. Hate to walk away after 15 years.
I also put went sprues close to the interface of the abutment.
You also mentioned, You place the ring in the pressure pot? I don't have one, where would you get it, and is it worth it? or just easier to replace investment in your opinion?

I use a Lang Invest Press, and run it up to 80psi for all of my castings. http://www.langdental.com/dental-products/small-equipment/investprestm.html

For spruing of the cast to abutments, I sprue them towards the top of the abutment at an angle and the run a 20 gauge vent from the base area to the bottom of the ring. The Fujivest II can be very soft to extract from the rings, especially under the twenty minute mark. I also lube up my rings and bases with PAM cooking spray before investing. This has helped with removal from the ring former. These problems have only happened to me on the 60 gram rings. If you are experiencing it on larger rings, you may have a bad batch of Fujivest II , or bad liquid.
 
JMN

JMN

Christian Member
Full Member
Messages
12,205
Reaction score
1,884
I use a Lang Invest Press, and run it up to 80psi for all of my castings. http://www.langdental.com/dental-products/small-equipment/investprestm.html

For spruing of the cast to abutments, I sprue them towards the top of the abutment at an angle and the run a 20 gauge vent from the base area to the bottom of the ring. The Fujivest II can be very soft to extract from the rings, especially under the twenty minute mark. I also lube up my rings and bases with PAM cooking spray before investing. This has helped with removal from the ring former. These problems have only happened to me on the 60 gram rings. If you are experiencing it on larger rings, you may have a bad batch of Fujivest II , or bad liquid.
Yep, we had issues with slow setting when it was very cold outside too. We ran a brush with vaseline on the ring and base for the same removal reason, wish we'd thought of the spray Pam idea.
 
S

stanleyn

Member
Full Member
Messages
53
Reaction score
1
Yep, we had issues with slow setting when it was very cold outside too. We ran a brush with vaseline on the ring and base for the same removal reason, wish we'd thought of the spray Pam idea.
Thank you very mach for time You guys spent to help me. I appreciate it. I use 90grams bags. And, no, when I use two or more bags ring I don't have problems.I also use generous amount of Vaseline.
Lang Invest Press is somewhat costly, more than $600. I am not sure if it worth to invest more then $600 in it, or just replace the investment. Do you use it for E-Max also to reduce the reaction layer? I use Ivoclaire investment for my E-Max it is costly, but works well. The pressing fits very well under the microscope, however, I do have reaction layer, and I even so I use Zubler furnace I can't read off the reaction layer. May be Invest Press could help with this.
 
JMN

JMN

Christian Member
Full Member
Messages
12,205
Reaction score
1,884
Thank you very mach for time You guys spent to help me. I appreciate it. I use 90grams bags. And, no, when I use two or more bags ring I don't have problems.I also use generous amount of Vaseline.
Lang Invest Press is somewhat costly, more than $600. I am not sure if it worth to invest more then $600 in it, or just replace the investment. Do you use it for E-Max also to reduce the reaction layer? I use Ivoclaire investment for my E-Max it is costly, but works well. The pressing fits very well under the microscope, however, I do have reaction layer, and I even so I use Zubler furnace I can't read off the reaction layer. May be Invest Press could help with this.
We did small rings with 90g bags for Full Gold, max 3 FCG per ring to keep from throwing too much metal at once. Otherwise we usually did a 90g bag and a 60g bag in a larger 150g ring. max 8-9 copings avg 6-8. The UCLAs did just fine in either for us.

OH! We used slightly more liquid in winter than in summer. In winter we added 1ml more, roughly in the proportion required. We went to doing this year round and in about '10 had the investment taking longer to set, seeming more liquid than normal and went back to the 'recommended' amounts.

Before you throw yourself into a whirling headache of learning the tweaks and personality of a new material, try a new bottle of liquid from a different lot #. Done it a time or two and found it was one lot or shipment that had issues. GC may or may not have been at fault, hard to tell what temp the shipping truck insides get to.

If you get an answer, please let us know. Hope you do.
 
JKraver

JKraver

Well-Known Member
Full Member
Messages
3,422
Reaction score
451
Could refrigerate liquid.
 
K

KIM

Well-Known Member
Full Member
Messages
507
Reaction score
157
Very good point JMN. This is absolutely the time of year when labs suddenly see issues with their investment and it is largely due to seasonal temperature and humidity fluctuations which will require slight adjustments to ratios and handling...
 
S

stanleyn

Member
Full Member
Messages
53
Reaction score
1
I use a Lang Invest Press, and run it up to 80psi for all of my castings. http://www.langdental.com/dental-products/small-equipment/investprestm.html

For spruing of the cast to abutments, I sprue them towards the top of the abutment at an angle and the run a 20 gauge vent from the base area to the bottom of the ring. The Fujivest II can be very soft to extract from the rings, especially under the twenty minute mark. I also lube up my rings and bases with PAM cooking spray before investing. This has helped with removal from the ring former. These problems have only happened to me on the 60 gram rings. If you are experiencing it on larger rings, you may have a bad batch of Fujivest II , or bad liquid.
I am tempting to buy this $600 pressure pot...
 
S

stanleyn

Member
Full Member
Messages
53
Reaction score
1
Or you could use a regular pressure pot and just have it under 30lbs pressure... just sayin...
I don't do cooking in my family. What is "regular" pressure pot? And how would I use it?
 
JKraver

JKraver

Well-Known Member
Full Member
Messages
3,422
Reaction score
451
Its not 80lbs, but it will make them denser than ambient air pressure.
 
JKraver

JKraver

Well-Known Member
Full Member
Messages
3,422
Reaction score
451
Thanks man!.....Just ordered...$60 no brainer...
Make sure you didn't get the hydraulic kind you need pneumatic. If its the small manual one you have to fill it with water to work. Added water to investment is bad news.
 
JKraver

JKraver

Well-Known Member
Full Member
Messages
3,422
Reaction score
451
You can also use it to make models a little denser, 22-27 can get pretty small and can use all the help they can get.
 
doug

doug

Well-Known Member
Full Member
Messages
2,657
Reaction score
375
We've used a pressure pot (Lang) for years and it does a really nice job. Remember that if you are the kind of person who uses hollow sprues the pressure will cause them to fill with investment and you will be screwed.
 

Similar threads

Top Bottom