Martin H. Eastburn wrote:
It would sound that the sulfur acids are used for organic fluxes and
oils.

HCl is useful to 'clean' copper metals since it strips a layer off in
a chloride
and floats off leaving a bare and clean surface. e.g. clean a penny.
(and old one).

The chemical reaction is hot by itself. It also creates 'movement' in
the reaction and thus heats locally.

DON'T DO THIS UNLESS YOU WANT TO HAVE AN OVERFLOW...
A HCl or FeCl bath when nearly depleted - is depleted and heated
by adding aluminum. Fire and sparks and gas release. Hot
reaction.
I asked my chemistry teacher about this reaction after sticking a pencil
with an aluminium sleeve retaining the eraser into FeCl etching solution
and noting the violent reaction. She said it was the same type of
reaction as thermite but with chlorine instead of oxygen swapping from
iron to aluminium.

Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Joe wrote:
On Mon, 12 May 2008 20:02:12 -0400, Brian Lawson
wrote:


Hey Michael,

Short answer is yes. But it depends a lot on exactly what it is you
are doing, but the following is a guide line and used when building
model locomotive boilers of copper, after all the joints are done.

"To help clean the piece after soldering, it is quenched in "pickle",
a moderately strong sulfuric acid bath, or a pretty concentrated
solution of sodium bisulfate. Hydrochloric (muriatic) acid is better
for copper and brass. (Platter's call it "bright dip".)

Question: Why do they recommend sulfuric or sodium bisulfate first, if
muriatic is the preferred pickle? I'm not trying to be difficult,
mostly just curious as to what other materials model loco builders
might use for boilers.

Also, does the pickle work fine at room temperature?

Joe



Use two
containers, one for the pickle, the other for rinse water. Pickle will
eat holes in cotton and other vegetable fibers, and it can splash when
a hot piece is dropped into it. Wear an apron. Don't pick up a piece
in the pickle with iron tongs. Some dissolved copper will plate onto
the silver because of the galvanic action. Copper tongs are standard;
stainless steel might work. A hook of copper wire might suffice, and
don't hesitate to use your bare hands/ fingers if you have no broken
skin. "

I don't advise the latter, just in case!! Acid burns can easily go
right to the bone, as with lye also.

Take care. Brian Lawson,
Bothwell, Ontario.
ps...whatcha makin ??


----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet
News==----
http://www.pronews.com The #1 Newsgroup Service in the World! 100,000
Newsgroups
---= - Total Privacy via Encryption =---