Geo said:
Even though it's possible and some people do it that way, it is recommended that you glaze a melting dish to torch melt gold.
Correct - glazing a dish has always been recommended - as it should be - especially if you are doing small melts of just a "few" grams (as already explained/discussed) --- its just not "necessary"
Jon can correct me if I am wrong - but I don't think he made his comment "as a recommendation" - he was simply making a point that it is not "necessary" --- in other words doable --- to which - being how it came up I felt the need to post a more detailed explanation of the pros & cons to melting in a glazed or unglazed dish
Keep in mind - as I pointed out - "over" glazing a dish can/will present its own problems - something rarely mentioned - people are just told to glaze their dish
The point being - Jon was/is not wrong &/or posting mis-information in "pointing out" that it is not "necessary" to glaze your dish - in fact - IMO - Jon pointing out the fact that it is not necessary to glaze a dish opened this "fact" for discussion such that it provides members the opportunity to make a decision based on their circumstance
Let me put it this way --- why would I waste the half hour or so it takes me to "properly" glaze a dish in a situation where it is not necessary
Example; - say I have a ozt or more of karat scrap I want to melt to pour shot to go to AR (assuming of course I don't already have a glazed dish handy for the job) why would I waste a half hour of my time to do this melt - when it is not necessary
IMO - telling me I "
need" to glaze my dish - is in fact mis-information :!:
There is one more thing about using a unglazed dish that should be pointed out - if you are melting impure gold powders - the impurities tend to forum oxides (of the base metals) "
on the surface" of your molten gold - you don't always see them while the gold is molten - but they will be clearly evident when the gold cools --- because these oxides tend to be on the surface of the molten gold - & if you are using an unglazed dish - when you roll the gold in the dish - to pick up beads - &/or when you make the pour - the gold tends to roll out from under these oxides with the oxides hanging up on the rough surface &/or on the pour spout lip of the unglazed dish - the slower you roll the gold &/or slower the pour the more likely the gold is to roll/pour out from under the oxides - leaving the oxides hung up on the rough surface of the unglazed dish --- these oxides will show up as a streak as the gold rolls out from under it - if it's a bead of pure gold that hangs up on the rough surface of the unglazed dish - it will show up as a bead instead of a streak - which can then be picked back up by bring the larger pool of molten gold back around to it
What does that mean? --- it means when melting your powders (assuming your melt is big enough to work properly in an unglazed dish) you can use the dish to "somewhat" determine if your gold is actually clean or not by doing a "
slow" roll of the molten gold in the dish to see if oxides hang up on the rough surface
If so - & you are thinking ahead - you can have your water bucket for pouring shot already hand & you can decide to pour it to shot for going back to AR - rather then pouring it to a mold & ending up having to re-melt the mold pour to make shot for AR again
IMO - recommending glazing a dish should certainly stand as the "standard recommendation" --- but trying to discredit not glazing a dish as an option does not serve the purpose of this forum which is to provide information such that members can make informed decisions that best serve their circumstances
I hope between the fact that Jon brought the point to light & my efforts to explain the pros & cons has served that purpose
Kurt
