Subject: Re: Help: Sulfuric Acid/Revisited

From: [email-masked] (Jonathan M. Elson)
Date: 23 Sep 1996 18:54:39 GMT

Chester A. Roberts, Jr. ([email-masked]) wrote:

: A while back I asked for help on how/where tpurchase sfuric
: acid as recommended by Hiraoka in his silver soldguide-
: lines.  I received a number of replies including: swimming pool
: chemical "Sodium Bisulfate" which is used to lower pool ph.
:    Problem #1:  I bought the chemical, but there is no descript-
: ion of how to achieve a 10% acid solution.  I guessed and used
: 6.4 ounces (volume) with water to make a half gallon.  A theo-
: retical 10% of 64 ounces.  Caused some bubbles but didn't seem
: to do much to the metal.  I suspect this solution may be very
: very weak....
:    Problem #2: I also found an auto supply that sells battery
: acid.  Trouble is they don't list the strength of the acid.  The
: precautions on the box are pretty severe...I suspect that the
: acid may be way over 10% solution.
:    SOOOOOO..... If you actually know how to make a 10% solution
: using swimming pool conditioner (sodium bisulfate) OR how to make
: a 10% solution using battery acid, please let me know.
:    PLEASE no guessing...but if you do know I'd sure appreciate
: your advice!

I think batterty acid is 30% by weight (anyone: please correct me if
I'm wrong) - so if you dilute 1 part battery acid with 2 parts water,
(by volume) you will get very close to 10% by weight.  If you dilute 
1 part acid with 2 parts water by weight, you'll get even closer.

---

From: [email-masked] (Chester A. Roberts, Jr.)
Date: 22 Sep 1996 18:40:43 GMT

A while back I asked for help on how/where tpurchase sfuric
acid as recommended by Hiraoka in his silver soldguide-
lines.  I received a number of replies including: swimming pool
chemical "Sodium Bisulfate" which is used to lower pool ph.
   Problem #1:  I bought the chemical, but there is no descript-
ion of how to achieve a 10% acid solution.  I guessed and used
6.4 ounces (volume) with water to make a half gallon.  A theo-
retical 10% of 64 ounces.  Caused some bubbles but didn't seem
to do much to the metal.  I suspect this solution may be very
very weak....
   Problem #2: I also found an auto supply that sells battery
acid.  Trouble is they don't list the strength of the acid.  The
precautions on the box are pretty severe...I suspect that the
acid may be way over 10% solution.
   SOOOOOO..... If you actually know how to make a 10% solution
using swimming pool conditioner (sodium bisulfate) OR how to make
a 10% solution using battery acid, please let me know.
   PLEASE no guessing...but if you do know I'd sure appreciate
your advice!
   Regards, Chet Roberts
P.S. We've had heavy rain...phone line connections are pretty
noisey...please forgive any gibberish....

---

From: Bill Richmond <[email-masked]>
Date: Tue, 24 Sep 1996 10:02:07 -0700

> chemical "Sodium Bisulfate" which is used to lower pool ph.

    Sodium bisulfate is not sulfuric acid; rather it is sulfuric acid 
that has been half neutralized.  It is very weak, and not good for the 
agressive cleaning required.

> acid.  Trouble is they don't list the strength of the acid. 

	They should be able to tell you the specific gravity of the acid, 
>from  which the concentration can be calculated. (I think that this is 
about 20% acid, but I am not sure.) I can check this and post it later.
					Bill Richmond

---

From: Andrew Werby <[email-masked]>
Date: 24 Sep 1996 17:43:03 GMT

[email-masked] (Chester A. Roberts, Jr.) wrote:
>lines. 

[I don't see why you need to mess with sulphuric acid- just clean the 
steel along the intended joint mechanically, with a file, grinder, 
sandpaper, etc.]

 I received a number of replies including: swimming pool
>chemical "Sodium Bisulfate" which is used to lower pool ph.

[This doesn't make sulphuric acid. It is used as a pickle for 
non-ferrous metals, but is not recommended for steel. Being more 
reactive, steel oxidizes quickly in acid- this doesn't do it any good.]

Andrew Werby - United Artworks

http://users.lanminds.com/~drewid

---

From: [email-masked] (Tim Carter)
Date: Wed, 25 Sep 1996 07:19:09 Local

In article <[email-masked]> [email-masked] (Chester A. Roberts, Jr.) writes:
>From: [email-masked] (Chester A. Roberts, Jr.)
>Subject: Help: Sulfuric Acid/Revisited
>Date: 22 Sep 1996 18:40:43 GMT

<snip>Problem #2: I also found an auto supply that sells battery
>acid may be way over 10% solution.

Yes, it is. SG Should be around 1.2, about 30%.
 
>how to make a 10% solution using battery acid, please let me know.

>noisey...please forgive any gibberish....

Get yourself a hydrometer, Chet, and dilute battery acid to an SG of 1.066 for 
a concentration of 10%.

Remember to add acid to water, never, never the other way round, stir 
continuously, wear goggles and keep a supply of fresh water handy in case of 
accidents.

regards

tim

"My opinions are my own and other usual disclaimers."

---

From: [email-masked] (Robert Nichols)
Date: Wed, 25 Sep 1996 18:02:21 GMT

In article <[email-masked]>,
Tim Carter <[email-masked]> wrote:
:
:Get yourself a hydrometer, Chet, and dilute battery acid to an SG of
:1.066 for a concentration of 10%.
:
:Remember to add acid to water, never, never the other way round, stir 
:continuously, wear goggles and keep a supply of fresh water handy in
:case of accidents.

That "acid into water" bit is important only when working with the
concentrated acid.  Concentrated sulphuric acid has a very high affinity
for water, and the binding reaction is highly exothermic.  If you try to
add water to the acid, the water will boil and spatter the acid all over
you.  Once the acid has acquired a specific amount of water (six
molecules of H2O for each of H2SO4, if memory serves me), you now have
_dilute_ sulphuric acid, which does not generate heat when you add
additional water.

Battery acid is *way* dilute in this context.  (Hint: When a battery
needs water, do you first remove the acid from the battery, or do you
just pour water into the acid in the battery.)

With sulphuric acid especially, you have to make the distinction between
concentrated and dilute.  When you're in school, you learn that
sulphuric acid reacts strongly with steel but has little effect on lead.
Then you graduate and move into industry, where you discover that
*concentrated* H2SO4 is shipped in steel tank cars, but must be kept
away from lead, which dissolves in it rapidly.  ("Concentrated sulphuric
acid" is not even an acid, chemically.  It can't separate into ions
until it is mixed with water.)

-- 
Bob Nichols         [email-masked]
Finger [email-masked] for PGP public key.
PGP public key 1024/9A9C7955
Key fingerprint = 2F E5 82 F8 5D 06 A2 59  20 65 44 68 87 EC A7 D7

---

From: John & Theresa Egan <[email-masked]>
Date: Thu, 26 Sep 1996 13:25:33 -0700

> : A while back I asked for help on how/where tpurchase sfuric    
  .....Clip......

> 1 part acid with 2 parts water by weight, you'll get even closer.......................................................................

Chester,

A good hydrometer with numeric graduations can measure the specific 
gravity of your dilute acid and its % concentration can then be 
calculated by comparing the specific gravity of pure water (specific 
gravity = 1.000) and concentrated (100%) sulfuric acid (specific gravity 
= 2.52 ...I think). 

specific gravity of 10% acid = 90% of 1.000 + 10% of 2.52 = 1.15

Check the value of the specific gravity for conc.H2SO4 but otherwise the 
method should allow you to measure and adjust the concentration of your 
acid by adding acid or water. DON'T use (100%) concentrated acid!!!!! 
Even then only pour the acid into the water slowly while stirring.  

The same method for sodium bisulfate is more difficult due to the 
difference between the atomic weights of sodium and hydrogen.

(As above: Anyone, please correct me if I am wrong!)

John

---

From: [email-masked] (Mike Fallopian)
Date: 26 Sep 1996 16:02:28 GMT

In article <[email-masked]>, [email-masked] says...
>> 1 part acid with 2 parts water by weight, you'll get even 
closer.......................................................................
>specific gravity of 10% acid = 90% of 1.000 + 10% of 2.52 = 1.15

Just checked the CRC... the specific gravity of a 10% (weight) solution of 
sulfuric acid in water is 1.068.

Jeff

---

From: John & Theresa Egan <[email-masked]>
Date: Thu, 26 Sep 1996 22:43:39 -0700

> sulfuric acid in water is 1.068.

Jeff,

Thank you, I stand corrected. I screwed up the GMW for H2SO4.

John

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From: Jim Cook <[email-masked]>
Date: Wed, 25 Sep 1996 18:54:50 -0400

> noisey...please forgive any gibberish....

If you check out the September 1977 issue of Live Steam I think you will
find the answer to your question on page 37. The article is called "Find
the right solution for Acid Strengths" by Donald W. Exner.

In that article the author has graphed the amount of acid that is
combined with a given amount of water to reach a required solution. He
has two curves. The first is for new acid that has a specific gravity of
1.280. The other curve is for old acid with a specific gravity of 1.150.

-- 
Jim Cook   	|email:Home:[email-masked]
Agawam		|      Work:[email-masked]
		|Home Page: http://www.the-spa.com/jim.cook/