Borax ?

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bobgaz

Member
Joined
Apr 21, 2012
Messages
6
Here is a "newbie" question ..... Is the. borax used for curing my crucible Boric Acid and/or is it the soap powder?
Sorry for the probably dumb question.
Thanks
 
Wasn't there a slightly different kind of Borax that doesn't expand so much? I'm thinking maybe it was Geo that was talking about it and how it was easier to apply. Looking but not finding the post.
 
thats reagent grade borax.its bought at the chemical supply houses that other chemicals are sold. it has lower moisture and doesnt expand as badly. the super market brand works perfectly well. when applying the borax, apply to a hot, dry dish a pinch at a time around the top edge of the dish and push the melted borax to the middle with the torch flame. you only want to coat the inside of the dish and make it look wet. this is preparing the dish for a melt.
 
The reason it expands and tends to flutter about when heated is because the water of crystallization is being driven off. if you heat up your 20 mule-team borax to 450 degrees (f) for an hour or so in a shallow pan in an oven it should not expand. just keep it in a sealed jar after it comes out of the oven...
 
Geo said:
thats reagent grade borax.its bought at the chemical supply houses that other chemicals are sold. it has lower moisture and doesnt expand as badly.
That's not exactly right. What you're talking about isn't necessarily reagent grade (although I'm sure it could be)---it's either anhydrous borax, or borax glass. Both perform about the same, as they don't contain water. Borax glass has been melted, while anhydrous borax has simply had the water removed. Borax glass tends to be somewhat translucent, while anhydrous borax is white opaque, and on the hard side. Both are very tranquil when heated. They don't puff up, they simply get hot, then melt.

Harold
 
Harold_V said:
Geo said:
thats reagent grade borax.its bought at the chemical supply houses that other chemicals are sold. it has lower moisture and doesnt expand as badly.
That's not exactly right. What you're talking about isn't necessarily reagent grade (although I'm sure it could be)---it's either anhydrous borax, or borax glass. Both perform about the same, as they don't contain water. Borax glass has been melted, while anhydrous borax has simply had the water removed. Borax glass tends to be somewhat translucent, while anhydrous borax is white opaque, and on the hard side. Both are very tranquil when heated. They don't puff up, they simply get hot, then melt.

Harold

thanks Harold for the correction.
 
I've been meaning to ask this, so I will here as to not start another thread. I kno boric acid is added to borax sometimes. But can it be used straight?
 
boric acid is a part of borax. boric acid is formed by dissolving borax in hcl. i dont think that boric acid can be substituted for borax in any way.
 
I didnt think so. I tried it a few days ago on some silver and it is really sluggish and turns black, but the black may be from my filter paper. The lot was so small I had to burn it in the crucible. But I think that is typical to burn the paper.

Regardless I'll be acquiring some 20 mule tomoro.

Thanks for respondIng Geo, I'm going to bed now...
 
I have used boric acid as a flux for silver and gold with success. It is very hard on refactory materials so it will shorten the useful life of your melting dishes and crucibles.
 
Ok I'm a first timer I have some 20 m t borax Are you saying heat it to 450' then put the pins in is that it Or could someone spell it out for me. Or should I search for some other chemicals. Which process work with the least amount of risk. Thanks for your patience
 
Horrace said:
Ok I'm a first timer I have some 20 m t borax Are you saying heat it to 450' then put the pins in is that it Or could someone spell it out for me. Or should I search for some other chemicals. Which process work with the least amount of risk. Thanks for your patience


You should study the forum, and forget about borax, until you are ready for it. You will know what it is used for if you study the forum.

Jim
 
Horrace said:
Ok I'm a first timer I have some 20 m t borax Are you saying heat it to 450' then put the pins in is that it Or could someone spell it out for me. Or should I search for some other chemicals. Which process work with the least amount of risk. Thanks for your patience

Sadly, Horrace, I don't think that is what Publius was getting at. I believe he was discussing a way to prevent the borax from being flightier than a blonde bombshell stewardess from the 70's. Essentially, a refined way of having an easier melt. Other answers will roll in, but essentially, you should read Hoke first, you need an understanding of the chemicals first.
 
Horrace said:
Ok I'm a first timer I have some 20 m t borax Are you saying heat it to 450' then put the pins in is that it Or could someone spell it out for me. Or should I search for some other chemicals. Which process work with the least amount of risk. Thanks for your patience

this is used as flux for melting refined gold and silver. the borax glass absorbs a minute amount of impurities in the melt. normally used in conjunction with other fluxes when doing fire assays.it will not absorb large amounts of base metal.
 
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