Cast Partial Framework

[MrB]

Hello everyone! I tried to cast a framework for partial denture the other day using castable resin in investment. And the result was far from perfect. Can you, please, take a look at it and tell me what I did wrong? I attached pictures of it in the link. Thank you!

 

[MrB]

Photos

 

[erzdaemon]

You could double check the IFU's of the Resin, IIRC they may need special investment material and/or parameters.

Which Resin is it?

 

[MrB]

I used Siraya Tech Purple Cast for printing.

And investment is Bego Ballavest SH + Begosol HE.

 

[erzdaemon]

Castable - Cast Resin User Manual

Check out Siraya Tech Blue Castable Resin User Manual for post-processing steps and burnout schedule.

siraya.tech

extract what i think is important ( mostly quick cleaning and drying and the used investment material ):

The shelf life of the resin is 2 years.

Even if it can be stored for such a long time, we still recommend that you use it in half a year.

4. Cleaning

• Use a painter brush (or any brush made with hair) remove excess resins on the printed part with Use 95% concentrated Ethanol (preferred) or IPA to clean. Some form of methnol should work but make sure it does not contain acetone.
• After 2-3 minutes of cleaning action, remove alcohol with a hair dryer or air blower. For complex part with lots cavities, it may be a good idea to clean/dry multiple times.
• Dry as quickly as one can once the print is cleaned with compressed air
• Surface should be matte, if you see shiny spots, repeat cleaning on those spots.
• AVOID USING WASH AND CURE ALL IN ONE MACHINE

5. Post Curing

• Make sure print is completely dry before proceeding.
• It is important to fully cure Cast to ensure clean burnout.
• It is also important to ensure print does not absorb moisure as it may also affect burnout results
• We recommend putting print in glycerine to speed up curing without getting water on the print.
• Curing time varies with light fixture but most likely to be over 10 minutes and longer.
• AVOID USING WASH AND CURE ALL IN ONE MACHINE
• Fully Cured Print Should feel hard and a bit brittle

6. Investment and burn out recommendation

Our users have reported successes with Plasticast® investment by Ransom & Randolph
https://www.ransom-randolph.com/plasticast
Recommendend Burn out schedule can be found here:
https://www.ransom-randolph.com/_files/ugd/cc5f22_902ad781b4e74bf3b3d55bff34f7fe6c.pdf

Some user may have hard time finding Plasticast, here is an alternative found in UK and recommended by VOG
https://www.srs-ltd.co.uk/products/investment-powder/classic

 

[RPD Josh]

Photos

I have been doing partials for many years now, starting with hand waxed and cast, print to cast, and now slm printing them. I believe your going to have to make most aspects of that frame design more thick. When casting the frames they must have enough room for the liquid metal to flow through to make it to the tips of clasps and lowest portion of major connector. Keep in mind you must design it to be able to be cast it and not necessarily the exact thickness you would like the final product to be and account for the finishing and polishing as well. You might want to add a couple additional sprues towards the portion furthest from the button (area where the liquid metal enters from casting machine) to help the flow of metal reach those furthest points before it cools not allowing it to reach all those areas. Any questions feel free to reach out and ask for me at GPS Digital RPD