Flash on castings

[Harleyrider]

A little help please, on the few pfm's we do lately we have really liked milling our frameworks out of Jensen wax. We are experiencing slight flashing on copings/frameworks that we have not had when using the dipping wax method. We have tried both slow and rapid burnout with same results, any tips?

 

[JMN]

Have you chaged debublizer/surfectant? Sometimes I'd get that with what think were the temp diffweences between the water, liquid, wax and debublizer mking the debublizer relativly thicker. I'd sometimes see it's color 'halo' during investing the first of the day and know to let it bench set a bit longer after spruing before invsting to let everything acclimate and let more of the debublizer dissipate/evaporate/whatever it does.

Edit: I think this was "Wax-it" debublizer,which smelled like windex to me.

Hope something in that ramble helped.

 

[JMN]

Another thought is the rills from the mill burr trapping/holding more surfectant per verticle mm than dipped as it has vastly more surface area from burr line depth vs burr line shallow between burr paths than the relativly smooth and straight dip coping.

Edit: Somebody please take that sentance out to the woods and put it out of its misery

 

[Bumfrey]

Have you tried putting them in a cold burnout furnace?



then turning it on......

 

[JMN]

Have you tried putting them in a cold burnout furnace?



then turning it on......

Wish I could hit funny and agree!

 

[Mike2]

My advice would be to lengthen the bench set by a min and make sure to allow 1 min outside of ring. In addition lay rings on the side to start, then stand up after first 15 mins. I had experienced this with resin patterns and the Jensen wax is very hard and dense. What you are experiencing is micro fractures from the rapid expansion of the wax prior to burning. My 2 cents, otherwise I am sure Terry or Ceasar at Jensen can elaborate more articulate than myself, that being the science behind the scenes.

 

[sndmn2]

Argen also suggests starting out with the ring on its side.