Resin Casting issues

[TheLabGuy]

Could be a couple factors as others have stated...cold casting, or resin wasn't burned out all the way (which could be due to spruing technique),or the resin is too thin. Therefore, you have a mystery on your hands. I'd increase the burnout temp and make sure molten metal is at proper temp before casting (whether it's casting arm or induction). Although, I'd personally suspect this won't solve your issue every time and that it's because it was printed too thin or the resin didn't get all the way out during the burnout phase. Keep us posted, we like mysteries here...

 

[JMN]

Another option is you are doing everything right and your thermocouple is losing accuracy.

Mine always got replaced yearly with the element as Prevetative Maintenance, stinks to be down for 2 days waiting for the oven mfg to get one from his supplier...

 

[Bumfrey]

My 2 cents from experience.

Investment too cold. Remove from furnace and cast asap, no messing about. I actually melt metal first, then pull ring out of furnace, reheat metal which is very fast and cast.
Pattern too thin. The cad may say 1mm or 0.8mm, but i have had cases when it comes out a little thinner than stated. Check it.

At that temp i think all the resin will be gone personally. <--- may well be wrong....

 

[Mike2]

I am no expert but everything points to cold cast. I would check accuracy of burnout oven as stated and we always laid rings sideways then turned upright 30 mins before casting. My 2 cents is on thermocouple.

 

[Bryce Hiller]

Casting SP copings today. Going to burnout longer and a little hotter. Will post results later. Thanks everybody!!

 

[Bryce Hiller]

Casting turned out great after increasing temp to 1650 and holding for 1.75 hours.

 

[BobCDT]

I would add a hand waxed or just dipped coping to the ring so you can start to eliminate variables. If the hand waxed unit casts complete and the printed unit fails it's probably the 3D print material. If they both fail, the metal and or ring are too cold.

 

[Affinity]

Milled wax takes a long time to fully burnout, I was having jagged margins on my pressings. Now I go above 900c then bring it back down to 840c for 2+ hours. If youre wondering, invest some of the wax and do your normal burnout process but take it out when you would cast and let it cool and cut it open.. but it sounds like youve got it figured out.

 

[GarryB]

Question for the group: We've started 3D printing all of our FCG and PFM substructures. The fit is great, but we've been getting a large number of miscasts with our copings. We're having everything printed at Argen and we use WhipMix Hi-Temp investment. cycle is up to 800 at 15 degree heat rise per minute, hold at 800 for 30 minutes, full heat rise to 1600 and hold for 1 hour.

Any ideas what we need to change? Thanks a bunch!

Just curious, if your sending your 3D designs to Argen, why not just get them to SLM? No investing, burning out, de vesting, trimming, possible mis casts. We use them for this reason.

 

[Bryce Hiller]

Just curious, if your sending your 3D designs to Argen, why not just get them to SLM? No investing, burning out, de vesting, trimming, possible mis casts. We use them for this reason.

That was a consideration. However, we have a 3D printer of our own on the way, so we wanted to get some of the "kinks" figured out before it got here.