[TheForge] Forge welding

[Bruce Freeman]

"James,

I'm not sure about that.  I know that manufacturers do issue MSDS's
that do  not contain complete lists of ingredients.  I don't know
whether that's legal, but it is done.

I found the following on the "FAQ" tab on the webpage,
http://www.20muleteamlaundry.com/about

"How much Borax is in 20 Mule Team?
"20 Mule Team® Borax is comprised of 99.5% pure borax, a naturally
occurring mineral composed of sodium, boron, oxygen, and water. (The
scientific name for borax is sodium tetraborate decahydrate.) The
remaining 0.5% is composed of trace minerals."

Note that it doesn't say whether those trace minerals are naturally
present or added by them.

According to Wikipedia, Morton Salt was made free-flowing by an
addition of a chemical.  "Originally, the company had added magnesium
carbonate as an absorbing agent to ensure that its table salt poured
freely; calcium silicate is now used instead for the same purpose."
If one of those chemicals is used in borax, its effect would probably
be nil.

It is entirely possible that a higher-melting chemical is present in
20 Mule Team Borax.  And I certainly can't challenge experience.  I
often note that long-time practitioners of an art (especially
blacksmithing) often know a lot about the practical aspects of their
art.  When they attempt to explain their observations from a
theoretical perspective, they often spout nonsense.  But that does not
in the least affect the truth of their practices.

One more thing:  Chemists routinely dry chemicals at temperatures of
about 110*C or so (about 230*F).  Usually this drives off all the
water.  Bound water may be a different story, but that MSDS lists the
melting point as 144*F (62*C), so I expect this will work for borax.
(By contrast, the melting point of anhydrous borax is listed by
Wikipedia as 743*C = 1370*F.)  In my experience, borax foams when
applied to hot metal -- no doubt because it's driving off the water.
Less than a red heat fails to melt the borax over the metal, probably
partly due to the high melting point of the remaining anhydrous borax.
 So, what I suggest is to dry your 20-Mule Team borax in an oven at
maybe 230*F for an hour, then cool it in a closed container (like a
cocoa tin) to keep water out.  This avoids the need to grind the
glassy mess you get from melting it at high temperatures.  I have not
tried this myself and am basing my recommendation on experience with
many other chemicals.  (I am a chemist.)

On Wed, Jul 27, 2011 at 1:47 AM, James Binnion <jbin at well.com> wrote:
>
> Chuck I don't doubt there is some discernible difference between high purity anhydrous sodium borate and laundry additive grade sodium borate decahydrate as a flux.  But my understanding is if they add an ingredient to a product it must be in the MSDS. Did they at one time add an anti caking additive,  possibly, but every MD SDS I have seen for it lists just sodium borate decahydrate
>
>
> On Jul 26, 2011, at 8:54 PM, Chuck Robinson wrote:
>
>> Since the borax is not USP grade I doubt it is chemically pure but the
>> impurities are also not listed in the MSDS sheet, as long as they are
>> not dangerous, toxic or carcinogenic.
>> I'm not an expert on the subject.
>> Chuck
>
> James Binnion
> jbin at well.com
>
>
>
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-- 
Bruce
NJ