# Melting Dish



## Long Shot (May 10, 2015)

So in a previous post earlier this week I mentioned that I over glazed my new melting dish with Borax. It was my first go at this and although I had read (from one of Harlold's contributions) that not a lot was needed I guess I didn't know what "a lot" was - I wanted to get the dish fully seasoned and realized after doing this and before melting my powder that I had probably used too much. This became readily apparent when the cooled button would not release, i.e. held firm by the solidified flux. I also have several very small globules frozen in the matrix at this time. The question is - what do I do about this or more specifically, is there anything that can be done to lessen the flux level and recover the globules? The dish is new and I hope I can save it.

Thanks for any input.

Jeff B


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## jason_recliner (May 10, 2015)

I write not from experience, but I recall reading recently probably an old post about this. Borax melts before gold does, so if I remember correctly, you can just remelt your gold. As soon as you remove the torch your bead will almost immediately resolidify. Pluck it out with tweezers before the borax sets. 
Extrapolating form that, you could probably just reheat your borax to below gold melting temperature.

My silica dishes arrived on Friday. I bought spares. I'm not ready to use them yet. My greatest fears are not getting enough heat from my propane torch in the first place, or blowing my tiny powders out of the dish with the flame.


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## Long Shot (May 10, 2015)

Thanks Jason, I should have bought a couple more as well. I have a Oxy-Acet rig so no problem with the melt and set the torch a little rich as advised. I too would be worried about the velocity and adequacy of the propane torch, good luck.


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## Lou (May 10, 2015)

Heat it up hot and sprinkle just a light dusting of dry soda ash on the whole of it. Allow it to melt in and it will thin the glaze. Wear eye and skin protection, flux and molten glass are unforgiving.


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## Anonymous (May 10, 2015)

There is another option- dilute Sulphuric acid dissolves Borax and I've heard that some people use it to clean crucibles (not graphite ones of course)


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## Lou (May 10, 2015)

Just use the soda ash, mk?


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## Geo (May 10, 2015)

What Lou said and more heat. If you add too much borax to begin with, melt the borax and just pour the excess out before melting the metal. If you melt the borax and it puddles in the bottom of the dish, it's too much. It's hard to get the borax too hot with a torch. I have melted a small spot on a dish I bought from lazersteve once with an oxy/acet torch but it wasn't easy. I had to use the maximum fuel the regulator could put out. I do things like that to test durability.


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## Anonymous (May 10, 2015)

Lou said:


> Just use the soda ash, mk?



Apologies mate I wasn't trying to usurp your advice 8) 8) 

Remind to read the post above my reply next time haha


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## philddreamer (May 10, 2015)

Jeff B, do you have a mold were you can pour the molten gold?

Since you have an oxy/acet torch, re-melt; add a bit of soda ash as recommended above; pour the gold and the excess borax into the mold. 
The dish is hot, continue to apply heat after the pour, thus getting rid of any excess borax; like killing two birds with one stone! 8) 

Make sure no borax runs down the side of the dish.

Take care!

Phil


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## Long Shot (May 10, 2015)

Thanks to all of you for the decent advice. I am glad that it is a relatively simple fix and I am in no hurry to recover the "globules". I did try to heat er' up and pour off the excess borax before I made my melt but it didn't want to flow, I'm thinking because the dish was new and it had a bonding moment, for lack of a better term. My next move is to activate my home built Au stripping cell (built with the good advice of ya'll) and deal with my plated stuff. If I was to apply the soda ash to the dish just before I applied the next batch of clean Au drops (obviously allowing it to cool beforehand) would that serve the dual purpose of recovering the globule materiel stuck in it with the new material? I am thinking so but am just wondering if I am on the right track.

Lou- I have read many of your posts and you are obviously very well versed and I appreciate you taking the time to assist me, especially being a noob - it must get dry. The same to you Geo - watched your videos here and on YouTube and have taken heed to your advice on more occasions than you know. It would not be possible for many of us to do these incredible things without the guidance and education of all of you wise people provide, by this I mean all of you. Thank you again.


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## FrugalRefiner (May 10, 2015)

Long Shot said:


> Thanks to all of you for the decent advice. I am glad that it is a relatively simple fix and I am in no hurry to recover the "globules". I did try to heat er' up and pour off the excess borax before I made my melt but it didn't want to flow, I'm thinking because the dish was new and it had a bonding moment, for lack of a better term. My next move is to activate my home built Au stripping cell (built with the good advice of ya'll) and deal with my plated stuff. If I was to apply the soda ash to the dish just before I applied the next batch of clean Au drops (obviously allowing it to cool beforehand) would that serve the dual purpose of recovering the globule materiel stuck in it with the new material? I am thinking so but am just wondering if I am on the right track.


Remember that when you melt, if there are base metal impurities, some of them will oxidize in the heat of the flame, and those oxides tend to be absorbed into the borax. Pure gold will melt leaving only a slight pink or purple tint to the borax. Other metals will create other colors. Soda ash is a reducing agent. It will cause many metal oxides to be reduced to their metallic form. When you clean a dish with soda ash, you must assume that any metal recovered is likely contaminated by base metals, and will need to be re refined. If you're melting your next batch of clean gold, you don't want to contaminate it be reducing base metals into the melt.

If you just need to thin the flux, add a bit of fluorspar.

Dave


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## Long Shot (May 10, 2015)

Interesting you say that Dave. There is an indication of "blackness" in the bottom of the dish. Not sure if that is base metal or just from the fact I was running my torch rich. It appeared after the second melt to get the gold liquid and pour into a cold water beaker. The button looked good, had a deep pipe, and has the luster of what I would expect to be pretty pure gold given the indications of change from double refining and wash cycles. That said, it was my first attempt and the raw material was very dirty. I would like to start afresh on the next go round without the possibility of base metal contamination to be sure. Excuse my ignorance, I will have to look up "fluorspar". As far as the few small globules of gold frozen in the borax, how would that effect that?


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## FrugalRefiner (May 11, 2015)

Fluorspar is a mineral, calcium fluoride (CaF2). It will thin borax flux, allowing the small globules to move around easier and combine into a larger glob. 

Both soda ash and fluorspar will attack your melting dish, shortening its life.

Dave


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## Long Shot (May 11, 2015)

Ok, seems like soda ash will be easier for me to acquire. I will use it sparingly to preserve the dish. Thanks again.


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## rickbb (May 12, 2015)

When I Google calcium fluoride the first thing that pops up is pills on Amazon that supposedly are a treatment for cold sores and hemorrhoids, of all things. Some strange "cell salts" homeopathic therapy.

The next is for places selling it by the ton. 

Would the pills crushed up be a viable source for us hobbyist/backyard guys to use who only need very small amounts?


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## philddreamer (May 12, 2015)

I bought my flourspar from Action Mining Services in Sandy, Oregon.

Phil


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## Long Shot (May 12, 2015)

Rick - might be worth a try, probably a lot of filler material though.

Phil - thanks. I would like to buy a lot of things out of the States, from LazerSteve for example, however, as a Canadian, we get hosed in many creative ways! The exchange is one thing (about 25% now) and our government likes to collect unreasonable duties, then there is unreasonable brokerage and then there is the ever increasing shipping. By the time a $30 US item gets to my door it costs me about $90 CND. Canadians would do a lot more business with Americans on small scales if the above weren't the case.


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## FrugalRefiner (May 12, 2015)

Fluorspar, also known as fluorite, is a natural mineral. If you can find a rock shop, gem and mineral shop, rock show, etc. somewhere, look for fluorite. It's sold as a collectible mineral. You should be able to find some inexpensive (low collector value) pieces for a buck or two. Ask if they have any that are all banged up or any pieces that have chipped off. Clear material is better, as the various colors come from different impurities.

Dave


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## Geo (May 12, 2015)

Any good, high grade optical glass is most likely fluorspar. Fluorite is used in cameras, scopes, binoculars, magnifying glass or any expensive lens. You can buy it on Ebay or crush your own.


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## butcher (May 13, 2015)

Check your local rock shop.
https://www.google.com/?gws_rd=ssl#q=flourspar+
https://www.google.com/search?q=fluorspar&biw=1280&bih=891&source=lnms&tbm=isch&sa=X&ei=PjxTVd_9JdGvogSXu4HoCg&ved=0CAYQ_AUoAQ


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## Lou (May 13, 2015)

Legend mining supplies


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## snail (May 13, 2015)

Try a ceramic supply company, one near me has flouospar and several other useful chemicals.
Dale


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## Long Shot (May 13, 2015)

Jeez, the value of this forum just grows every time I ask questions. I am not a geologist, chemist, etc.. What I can say is that about 25 miles north of me there are several abandoned fluorite mines from the turn of the century. Shouldn't be hard to pick up a specimen or two. Also, Geo - I have some lens from a projection TV, are these qualified?

One way or another this is great advice and I thank you all.


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## Geo (May 14, 2015)

Long Shot said:


> Jeez, the value of this forum just grows every time I ask questions. I am not a geologist, chemist, etc.. What I can say is that about 25 miles north of me there are several abandoned fluorite mines from the turn of the century. Shouldn't be hard to pick up a specimen or two. Also, Geo - I have some lens from a projection TV, are these qualified?
> 
> One way or another this is great advice and I thank you all.



I found that any lens that refracts red light is fluorite. If you can look at the lens at any angle and it looks red, it's fluorite. I think the magnifying lens in projection screen tv's is fluorite. At any rate, some silica glass in the mix, especially on a head assay, is a good thing.


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