From: REMOVE_THISdwilkins@means.net (Don Wilkins)
Newsgroups: rec.crafts.metalworking
Subject: Re: Low melting alloys
Date: Sat, 06 Mar 1999 11:42:37 GMT

On Fri, 05 Mar 1999 19:02:47 -0500, nhull@mindspring.com (Nick Hull)
wrote:

>In article <375fa682.1227611445@news.atl.bellsouth.net>,
>ke4zv@bellsouth.net (Gary Coffman) wrote:
>
>> On 1 Mar 1999 11:33:45 GMT, dgoncz@aol.comYukSpam (DGoncz) wrote:
>> >I could melt a puddle of 158 F melting alloy into the cup... but
>> >bismuth and cadmium are toxic. I need to check and see if either is in
>> >the spec.
>>
>> I believe both are components of low melting point alloys. The key thing
>> here is the specific heats of the mixtures. They are almost certainly less
>> than good old water (which has an amazingly high specific heat). So it is
>> unlikely you can store much heat this way. You'd do better to just put hot
>> water in the jacket.
>>
>> There is a salt (glaubar or something like that) which has a very large
>> heat of fusion, and a melting point that's in the range of the possible for
>> a hot cup. This is used to store solar energy in some solar heating
>> applications. That might be a better bet than toxic (and expensive)
>> low temperature metal alloys.
>
>Glauber's salt does not last forever, it "wears out"


Glauber's salt is sodium sulfate decahydrate (10 molecules of water of
hydration)

Melting point 33 degrees C not too far off from the temperature of
p---. A tad cold for my coffee.

The only way it is going to "wear out" is by losing some water of
hydration which it does about 100 degrees C.