The casting flame setting? The oxygen propane setting? Broken arm turns? Positing of wax patterns in casting ring? The burn out high temp? Heat soaking period? Heat potential of casting torch? Many questions.
i had holes too in the crowns / pontics until i stoped overheating the alloys with the torch and release them at the right time when casting .... hope this helps
i had holes too in the crowns / pontics until i stoped overheating the alloys with the torch and release them at the right time when casting .... hope this helps
When i started to see the alloys cylinders getting very red just before they lose their cylindrical shape i get out my ring from the oven and put it on centrifuge while keeping the flame at a safe distance from the alloys not to over heat them while i am taking my ring from oven , by that time the alloys start to lose shape and kinda look waving from the torch pressure , that the right time to ensure all of the alloys lost shape and in some cases of metal companies they unite all together , from there a few more seconds and i release..beofre that , my mistake was that i was waiting too much with torch until alloys were like liquid , then i was burning my alloys and all troubles came after that , thanks to the friends on this site i solved that .