On Mon, 12 May 2008 16:01:00 -0700, "Michael Koblic"
wrote:

I had to silver-solder two small components together today. To get a proper
solder flow I had to apply heat directly to the part of one component that
will later be visible. It ended up covered with black gunk. Is this what
they call firescale?

I tried removing it with steel wool with only partial success. In the end a
judicial application of 400 grit sandpaper did the trick without
obliterating the pattern underneath.

If this is firescale I understand Sparex (sodium bisulphate) is the thing to
clean it. Am I correct?

--
Michael Koblic,
Campbell River, BC


Sparex won't remove firescale. At least not any firescale I've had to
remove. A 50 % nitric acid/50% water solution will work though. Best
bet is to make sure you cover with flux the metal that is getting hot
enough to form firescale. Keep in mind that flux absorbs oxygen which
is why it helps prevent firescale and keeps the area to be soldered
free from oxidation. But flux only absorbs so much oxygen. It's best
to use enough heat to get the job done fast rather than use a small
flame.
ERS

I had to silver-solder two small components together today. To get a proper
solder flow I had to apply heat directly to the part of one component that
will later be visible. It ended up covered with black gunk. Is this what
they call firescale?

I tried removing it with steel wool with only partial success. In the end a
judicial application of 400 grit sandpaper did the trick without
obliterating the pattern underneath.

If this is firescale I understand Sparex (sodium bisulphate) is the thing to
clean it. Am I correct?

--
Michael Koblic,
Campbell River, BC

On Mon, 12 May 2008 16:01:00 -0700, "Michael Koblic"
wrote:

I had to silver-solder two small components together today. To get a proper
solder flow I had to apply heat directly to the part of one component that
will later be visible. It ended up covered with black gunk. Is this what
they call firescale?

I tried removing it with steel wool with only partial success. In the end a
judicial application of 400 grit sandpaper did the trick without
obliterating the pattern underneath.

If this is firescale I understand Sparex (sodium bisulphate) is the thing to
clean it. Am I correct?


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".) 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 ??

"Brian Lawson" wrote in message
...
On Mon, 12 May 2008 16:01:00 -0700, "Michael Koblic"
wrote:

ps...whatcha makin ??

This one is a miniature sundial

On May 12, 7:01*pm, "Michael Koblic" wrote:
I had to silver-solder two small components together today. To get a proper
solder flow I had to apply heat directly to the part of one component that
will later be visible. It ended up covered with black gunk. Is this what
they call firescale?

I tried removing it with steel wool with only partial success. In the end a
judicial application of 400 grit sandpaper did the trick without
obliterating the pattern underneath.

If this is firescale I understand Sparex (sodium bisulphate) is the thing to
clean it. Am I correct?

--
Michael Koblic,
Campbell River, BC

Next time cover everything with white (borax) flux to keep the air
off, but now try soaking the piece overnight in water and seeing if
any of the crud loosens.

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 ??

Hey Joe,

I'm no authority, but the suggestion was that the muriatic is "best"
for copper and brass, rather than just best all-round. Besides,
around here the sulphuric acid is a little less common at the local
stores than the muriatic, and to me slightly less corrosive generally.

Temperature only affects pickle time as far as I know, but heating an
acid causes undesirable vapours.

XXXXXXXXXXXXXXXXX

On Tue, 13 May 2008 09:29:45 -0400, 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 ??

FWIW,

Now days many of us who are building copper boilers for live steam use a
phosphor-copper rod. It melts at a slightly lower temp than traditional
"silver brase" has a wider range of temp between "solidus" and "liquidus",
runs like water when you want it to and most important requires no flux, the
phosphor makes it self fluxing so no "pickle" is required between re-works.
But this is only good for copper-copper work and one thing to beware of
though it not to get it too hot, you burn the phosphor out and yer screwed.

It goes by many names, at my welding shop it's a UniWeld product called
UNI-1000

--.- Dave (who's staring at the 4 foot long 8 inch diam copper piece for
the 2-10-2's boiler.)

"Brian Lawson" wrote in message
...
On Mon, 12 May 2008 16:01:00 -0700, "Michael Koblic"
wrote:

I had to silver-solder two small components together today. To get a
proper
solder flow I had to apply heat directly to the part of one component that
will later be visible. It ended up covered with black gunk. Is this what
they call firescale?

I tried removing it with steel wool with only partial success. In the end
a
judicial application of 400 grit sandpaper did the trick without
obliterating the pattern underneath.

If this is firescale I understand Sparex (sodium bisulphate) is the thing
to
clean it. Am I correct?


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".) 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 ??

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.

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 ??


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"Joe" wrote in message
...
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?


You may want to check with the manufacturers of your silver brazing alloy.
Here in the UK, model engineers (and professionals AFAIK) have mostly
abandoned sulphuric and hydrochloric pickling as unnecessarily dangerous.

The standard EasyFlo 2 flux used here can be removed with hot water and that
is what the suppliers (Johnson Matthey) recommend.

Many modellers here use citric acid solution. Resonably readily available
and harmless - leave the work in it for a few hours and it will do as good a
job as sulphric or hydrochloric without the risks.

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==----
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Newsgroups
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