Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

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  #1   Report Post  
Grant Erwin
 
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I've just cleaned a bunch of pieces of new black pipe by soaking them
in a hot TSP solution. They don't feel oily, and the lettering is gone,
but they are still vaguely black in color. I have read many times that
giving steel items a light etch in phosphoric acid will leave a thin
plating of iron phosphate which is a good strike coat for painting.
Since there are phosphate ions aplenty in TSP, might I have just
gotten the desirable iron phosphate coating without having to find a
bunch of phosphoric acid?

Second question: unfortunately, these parts aren't going to be painted,
they're going to be galvanized. The galvanizing shop is real leery of
items fabricated from black pipe because of the coating they get -
that's the reason for the TSP dip in the first place. I'm considering
a light etch in some dilute HCl (muriatic i.e. hydrochloric acid)
which should completely remove any doubt on the galvanizing shop's mind.
Question: can I neutralize HCl with TSP? I know that TSP in solution
is basic. I'm just wondering what happens when you mix TSP with HCl -
obviously, you'd get Na+ ions, H+ ions, PO3-- ions, and Cl- ions.
Sort of like a mix of phosphoric and hydrochloric acids, except for
the sodium. I can't figure it out, my college chem days are long over.

Final question: assuming #2 does NOT work, and further assuming it's
bad news to dump TSP into the sewer, is there any easy cheap way to
neutralize the TSP and make it less environmentally harmful? My
neighbor, no dummy, suggests using it as fertilizer. Does that make
any sense?

Grant Erwin
Kirkland, Washington

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Stan Stocker
 
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Grant Erwin wrote:

snip

Final question: assuming #2 does NOT work, and further assuming it's
bad news to dump TSP into the sewer, is there any easy cheap way to
neutralize the TSP and make it less environmentally harmful? My
neighbor, no dummy, suggests using it as fertilizer. Does that make
any sense?

Grant Erwin
Kirkland, Washington


Hi Grant,

I can't answer the first part of your post, far too long since I had
chemistry classes as well.

TSP alone is just fine as a fertilizer. It's the same stuff that used
to be in laundry detergents. It was banned in that application because
of the algae blooms it caused once the treated waste hit the rivers and
lakes. Remeber "Phosphate Free" stickers? It's just the "P" of the KNP
rating for fertilizer.

The only concern is what else is in the solution. I cook down the TSP
solution used for stripping old tools (likely lead based paint) and put
the sludge in a sealed can with kitty litter. It can then be turned in
at the local landfill just like old lead based paints, in the hazardous
waste disposal area for home owners. If the solution has a fair bit of
oil in it you may want to do the same thing, sort of hard to grow grass
over an oil spill :-(

Cheers,
Stan

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Ed Huntress
 
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"Grant Erwin" wrote in message
...

Final question: assuming #2 does NOT work, and further assuming it's
bad news to dump TSP into the sewer, is there any easy cheap way to
neutralize the TSP and make it less environmentally harmful? My
neighbor, no dummy, suggests using it as fertilizer. Does that make
any sense?



Disclaimer: I am a chemistry ignoramus.

That being said, the reason they took TSP out of laundry detergent is that
the phosphate is a fertilizer that caused some spectacular algae blooms in
wastewater treatment plants. The little bit you're going to add won't do
squat.

I toss a couple of tablespoons of the stuff into the washer, along with the
regular detergent, to wash my son's filthy sports uniforms. Now, if I could
only get back the enzymes that were in there until around 1970 or whatever,
we could be as clean as we were in 1968! g

Ed Huntress


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Ed Huntress
 
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"lane" lane_nospam@copperaccents_dot_com wrote in message
...


Ed
I know some of the dishwasher soap has enzymes in it, my wife swears by

it.
Wonder how it would work on clothes.
Lane



It's very caustic. However, you should see it get the sweat and grime out of
my baseball caps. Normally, I can hardly touch them with boiling lye. g

Suggestion for marital harmony: don't put your baseball caps in the
dishwasher while your wife if looking.

--
Ed Huntress
(remove "3" from email address for email reply)


  #5   Report Post  
lane
 
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"Ed Huntress" wrote in message
t...
"Grant Erwin" wrote in message
...

Final question: assuming #2 does NOT work, and further assuming it's
bad news to dump TSP into the sewer, is there any easy cheap way to
neutralize the TSP and make it less environmentally harmful? My
neighbor, no dummy, suggests using it as fertilizer. Does that make
any sense?



Disclaimer: I am a chemistry ignoramus.

That being said, the reason they took TSP out of laundry detergent is that
the phosphate is a fertilizer that caused some spectacular algae blooms in
wastewater treatment plants. The little bit you're going to add won't do
squat.

I toss a couple of tablespoons of the stuff into the washer, along with

the
regular detergent, to wash my son's filthy sports uniforms. Now, if I

could
only get back the enzymes that were in there until around 1970 or

whatever,
we could be as clean as we were in 1968! g

Ed Huntress


Ed
I know some of the dishwasher soap has enzymes in it, my wife swears by it.
Wonder how it would work on clothes.
Lane




  #6   Report Post  
Harold & Susan Vordos
 
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"Grant Erwin" wrote in message
...
I've just cleaned a bunch of pieces of new black pipe by soaking them
in a hot TSP solution. They don't feel oily, and the lettering is gone,
but they are still vaguely black in color. I have read many times that
giving steel items a light etch in phosphoric acid will leave a thin
plating of iron phosphate which is a good strike coat for painting.
Since there are phosphate ions aplenty in TSP, might I have just
gotten the desirable iron phosphate coating without having to find a
bunch of phosphoric acid?

Second question: unfortunately, these parts aren't going to be painted,
they're going to be galvanized. The galvanizing shop is real leery of
items fabricated from black pipe because of the coating they get -
that's the reason for the TSP dip in the first place. I'm considering
a light etch in some dilute HCl (muriatic i.e. hydrochloric acid)
which should completely remove any doubt on the galvanizing shop's mind.
Question: can I neutralize HCl with TSP? I know that TSP in solution
is basic. I'm just wondering what happens when you mix TSP with HCl -
obviously, you'd get Na+ ions, H+ ions, PO3-- ions, and Cl- ions.
Sort of like a mix of phosphoric and hydrochloric acids, except for
the sodium. I can't figure it out, my college chem days are long over.

Final question: assuming #2 does NOT work, and further assuming it's
bad news to dump TSP into the sewer, is there any easy cheap way to
neutralize the TSP and make it less environmentally harmful? My
neighbor, no dummy, suggests using it as fertilizer. Does that make
any sense?

Grant Erwin
Kirkland, Washington


I"m no chemistry wizard, but my years of precious metal refining taught me a
few things about hydrochloric acid and metals. I think I'd use a dilute
solution of hydrochloric to clean the steel parts you want to galvanize,
then neutralize the parts with sodium hydroxide (lye). That will prevent
the instantaneous rusting you would otherwise get. I used to run a small
ball mill. So long as I kept the interior basic (9 pH or higher), there was
no rusting.

If I'm not mistaken, when you take parts to be galvanized, they are
subjected to an acid wash prior to receiving the zinc dip.

Harold


  #7   Report Post  
jim rozen
 
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In article , Ed Huntress says...

Suggestion for marital harmony: don't put your baseball caps in the
dishwasher while your wife is looking.


And if you put motorbike transmissions in the oven, be
sure to use those Reynolds "roast-in" bags to keep the
90 wt fumes from escaping.

Jim

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  #8   Report Post  
jim rozen
 
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In article , Harold & Susan Vordos says...

I"m no chemistry wizard, but my years of precious metal refining taught me a
few things about hydrochloric acid and metals. I think I'd use a dilute
solution of hydrochloric to clean the steel parts you want to galvanize,
then neutralize the parts with sodium hydroxide (lye). That will prevent
the instantaneous rusting you would otherwise get. I used to run a small
ball mill. So long as I kept the interior basic (9 pH or higher), there was
no rusting.


I think this is pretty good advice. The base will neutralize
any acidity. The TSP is not really a base, IIRC it's like
most detergents, being a large molecule that is polar at
one end, and non-polar at the other end. So the polar
end grabs onto the water, and the non-polar end grabs
the oil or grease.

I also suspect that simply rinsing the parts well, and
using a mild base like baking soda will be enough, so
he would not have to deal with caustic NaOH solutions.

Jim

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Harold & Susan Vordos
 
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"jim rozen" wrote in message
...
In article , Harold & Susan Vordos says...


I also suspect that simply rinsing the parts well, and
using a mild base like baking soda will be enough, so
he would not have to deal with caustic NaOH solutions.

Jim


I'm afraid I'd have to strongly agree, Jim.

One of the negative experiences I had when refining was to get a drop of
nitric acid directly in one eye. Immediately the surface of my eye peeled
off. I had done something EXTREMELY stupid in that I had gone from the
machine shop, where I always wore safety glasses, to the lab, where I
removed them (??) while I tended to a large beaker of silver, to which I
added some acid. One drop, and only one drop, popped out of the beaker,
right into my left eye.

When an ophthalmologist looked at my eye, he told me how "lucky" I was. I
was told that the human body can quickly neutralize acid, which prevented
the acid from doing permanent injury to my eye. On the other hand, he said
that had the drop been lye instead, I would have been blinded because the
lye continues to destroy tissue. We can't neutralize base solutions nearly
as well.

I endorse the baking soda, and would encourage anyone facing this situation
to use it in place of lye.

Oh, yeah. Just as I was promised, the eye healed up with no lasting
effects, although I've often wondered if that's the reason my arms are too
short now. :-)

Harold


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jim rozen
 
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In article , Harold & Susan Vordos says...

One of the negative experiences I had when refining was to get a drop of
nitric acid directly in one eye. Immediately the surface of my eye peeled
off.


AAAAAAghhhh!!!

I'm sure glad I already ate. This story is was only
*slightly* less less horrifying than Roy's fire
extinguisher tale.

Because I see folks work with chemicals all the time
at work, and see how they do so under fume hoods, and
with goggles and whatnot all the time, I tend to have
about one reaction when I hear about things like this,
to pass out on the floor.

I had done something EXTREMELY stupid in that I had gone from the
machine shop, where I always wore safety glasses, to the lab, where I
removed them (??) while I tended to a large beaker of silver, to which I
added some acid. One drop, and only one drop, popped out of the beaker,
right into my left eye.


Yep, a lot of this stuff is pure habit. I see the researchers
do stuff with machinery, using no eye protection at all - and
they're the same folks who won't work under a hood unless the
sash is pulled most of the way down, and they've got eye
protection on all the time.

Jim

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Me Mine
 
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I am a chemist so I will try to clear up a few comments here. (Though I
know little about treating metal for galvanizing.) First TSP is not a
soap with a polar end and a non-polar end. It is just tri-sodium
phosphate, Na3PO4. This is the basic form of phosphoric acid, H3PO4. So
TSP is a base and can consume three equivalents of HCL, which would
produce H3PO4 and 3NaCl. This resulting solution would be quite acidic.
The key to neutralizing the HCl would be to use excess TSP so the
solution always remains somewhat basic. Sodium hydroxide, NaOH, will do
the same thing, but it is more basic and dangerous than the TSP. In any
case expect the solution to give off heat as you neutralize the acid.
So add the acid slowly to the base, while stirring the basic solution.
This should minimize any heat build-up.

Good-luck,

John

In article , jim rozen
wrote:

In article , Harold & Susan Vordos says...

I"m no chemistry wizard, but my years of precious metal refining taught me a
few things about hydrochloric acid and metals. I think I'd use a dilute
solution of hydrochloric to clean the steel parts you want to galvanize,
then neutralize the parts with sodium hydroxide (lye). That will prevent
the instantaneous rusting you would otherwise get. I used to run a small
ball mill. So long as I kept the interior basic (9 pH or higher), there was
no rusting.


I think this is pretty good advice. The base will neutralize
any acidity. The TSP is not really a base, IIRC it's like
most detergents, being a large molecule that is polar at
one end, and non-polar at the other end. So the polar
end grabs onto the water, and the non-polar end grabs
the oil or grease.

I also suspect that simply rinsing the parts well, and
using a mild base like baking soda will be enough, so
he would not have to deal with caustic NaOH solutions.

Jim

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Ed Huntress
 
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"Me Mine" wrote in message
...
I am a chemist so I will try to clear up a few comments here. (Though I
know little about treating metal for galvanizing.)


YO, John!....

This is a little like asking a doctor for medical advice over lunch, but...

When we use HCL to clean rusted steel, or to strip the galvanizing off of
electrical steel tubing, how should we neutralize it to prevent further
(accelerated) rusting? We've heard that dipping it in a lye solution will
leave NaCl in the pores of the cleaned metal and will lead to further
rusting, but we (I) wouldn't know the facts if our (my) life depended on it.

What's the story? Thanks, doc...

Ed Huntress


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jim rozen
 
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In article , Me Mine says...

I am a chemist so I will try to clear up a few comments here. (Though I
know little about treating metal for galvanizing.) First TSP is not a
soap with a polar end and a non-polar end.


Well that clears that up.

I guess as a crank turner I'm not that good a chemist!
Sorry for the confusion, guess I should have payed
more attention in class way back when. My last chemistry
class was in 1977.

But I suppose TSP was the same then as it is now...

Jim

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Gary Coffman
 
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On Fri, 31 Oct 2003 10:33:47 -0800, Grant Erwin wrote:
Question: can I neutralize HCl with TSP? I know that TSP in solution
is basic. I'm just wondering what happens when you mix TSP with HCl -
obviously, you'd get Na+ ions, H+ ions, PO3-- ions, and Cl- ions.
Sort of like a mix of phosphoric and hydrochloric acids, except for
the sodium. I can't figure it out, my college chem days are long over.


What you get is salt, NaCl. This salt residue will hide in every pore,
crack, and crevice of the part, promoting corrosion. You get the same
thing if you try to neutralize with lye or baking soda. So do *not* try
to neutralize the HCl. Just rinse the part off with plenty of hot water
(chlorides are soluble in hot water). The hotter the water, the better,
because solubility increases with temperature, and the hot water will
evaporate off the part faster, so the part doesn't stay wet long.

Note that the metal will be *extremely* clean at this point, and will
flash rust if you don't immediately oil it or otherwise protect it from
contact with oxygen. That's why the galvanizing guys normally do
the HCl dip and rinse immediately before galvanizing.

Note too that you don't have to worry about the rinse water going
down the drain. You need to use lots of it, and it will dilute any HCl
it washes off the part to harmless levels.

Final question: assuming #2 does NOT work, and further assuming it's
bad news to dump TSP into the sewer, is there any easy cheap way to
neutralize the TSP and make it less environmentally harmful? My
neighbor, no dummy, suggests using it as fertilizer. Does that make
any sense?


Sure, it *is* fertilizer. If you only have a few gallons of the stuff, dumping
it down the sewer isn't a problem either. The environmental concern was
when *everyone* was doing it (laundry detergents with TSP), and the result
was algae blooms downstream of the sewage treatment plant. But a few
gallons is nothing.

For *these* chemicals, dilution is the solution to pollution. That's not true
for some chemicals, or industrial quantities of most chemicals, but it is
fine for disposing of the small amounts of acids and bases used around
the home shop.

Gary
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Dan Caster
 
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Grant and Ed,
You might want to check the label on the box to see just what you
have. TSP is not easily procured in New York State. Yes it says TSP
on the box, but the fine print where it lists the ingrediants says
Sodium Carbonate. Sodium Carbonate is cheaper when bought as Sodium
Carbonate.

Here in Washington State, the fine print says contains TSP and Sodium
Carbonate. At least that was what the box at Lowes said. I have not
checked at Home Depot and ACE.

Dan


  #16   Report Post  
Ed Huntress
 
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"Dan Caster" wrote in message
m...
Grant and Ed,
You might want to check the label on the box to see just what you
have. TSP is not easily procured in New York State. Yes it says TSP
on the box, but the fine print where it lists the ingrediants says
Sodium Carbonate. Sodium Carbonate is cheaper when bought as Sodium
Carbonate.


We have both products here in NJ, Dan. The stuff I have is straight TSP.

Ed Huntress


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Me Mine
 
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Gary has hit the galvanized nail on the head. Any standard
neutralization of HCl will produce NaCl. Consequently, Gary's is right
when advising thorough rinsing. I believe the culprit to accelerated
rusting is the chloride ion. The only way to avoid this is to use a
different acid, i.e. sulfuric acid, H2SO4. I don't know if this is good
for cleaning steel or if it would cause problems with the ensuing
galvanization.

John

In article , Gary Coffman
wrote:

On Fri, 31 Oct 2003 10:33:47 -0800, Grant Erwin
wrote:
Question: can I neutralize HCl with TSP? I know that TSP in solution
is basic. I'm just wondering what happens when you mix TSP with HCl -
obviously, you'd get Na+ ions, H+ ions, PO3-- ions, and Cl- ions.
Sort of like a mix of phosphoric and hydrochloric acids, except for
the sodium. I can't figure it out, my college chem days are long over.


What you get is salt, NaCl. This salt residue will hide in every pore,
crack, and crevice of the part, promoting corrosion. You get the same
thing if you try to neutralize with lye or baking soda. So do *not* try
to neutralize the HCl. Just rinse the part off with plenty of hot water
(chlorides are soluble in hot water). The hotter the water, the better,
because solubility increases with temperature, and the hot water will
evaporate off the part faster, so the part doesn't stay wet long.

Note that the metal will be *extremely* clean at this point, and will
flash rust if you don't immediately oil it or otherwise protect it from
contact with oxygen. That's why the galvanizing guys normally do
the HCl dip and rinse immediately before galvanizing.

Note too that you don't have to worry about the rinse water going
down the drain. You need to use lots of it, and it will dilute any HCl
it washes off the part to harmless levels.

Final question: assuming #2 does NOT work, and further assuming it's
bad news to dump TSP into the sewer, is there any easy cheap way to
neutralize the TSP and make it less environmentally harmful? My
neighbor, no dummy, suggests using it as fertilizer. Does that make
any sense?


Sure, it *is* fertilizer. If you only have a few gallons of the stuff, dumping
it down the sewer isn't a problem either. The environmental concern was
when *everyone* was doing it (laundry detergents with TSP), and the result
was algae blooms downstream of the sewage treatment plant. But a few
gallons is nothing.

For *these* chemicals, dilution is the solution to pollution. That's not true
for some chemicals, or industrial quantities of most chemicals, but it is
fine for disposing of the small amounts of acids and bases used around
the home shop.

Gary

  #18   Report Post  
jim rozen
 
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In article , Ed Huntress says...

We have both products here in NJ, Dan.


Yes, but the downside on this is, you
also have Secuacus! :^)

Jim

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  #19   Report Post  
Ed Huntress
 
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"jim rozen" wrote in message
...
In article , Ed Huntress

says...

We have both products here in NJ, Dan.


Yes, but the downside on this is, you
also have Secuacus! :^)


But one never has to go there, nor to West New York, nor even to Perth
Amboy. d8-)

As for dangerous chemicals, they're like Black-eyed Susans are in some other
parts of the country. You can just gather them by the side of the road.

Ed Huntress



  #20   Report Post  
jim rozen
 
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In article , Ed Huntress says...

But one never has to go there, nor to West New York, nor even to Perth
Amboy. d8-)


I remember there was a lady who was running a operation in
Perth Amboy, she had a contract to barge sewage sludge
out beyond the limit. They caught her crew pumping
the sludge onboard the barges, and at the same time pumping
it overboard right at the dock! She was famous.

As for dangerous chemicals, they're like Black-eyed Susans are in some other
parts of the country. You can just gather them by the side of the road.


LOL.

Jim

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Koz
 
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Now you folks have me confused. We do metal conveyors for the potato
industry. In days gone by, potatoes were peeled by soaking them in a
very strong solution of caustic lye. This would dissolve the skins onto
a slimy mess that could be washed off, leaving an effectively peeled
spud (similar was done on peaches also). The practice has mostly been
replaced by steam peelers due to waste disposal problems.

The point is, the carbon steel conveyors and frames of these systems
lasted FOREVER. Even when steam cleaned, neutralized, etc, they never
rusted. The caustic acts as a protectant of some sort and prevents
corrosion rathern than causing corrosion as stated (on mild steel). The
slimyness of the lye acted as a lubricant also so the wear was reduced.
A conveyor just upstream, or just downstream (after the wash) might
last a year but the conveyors in the lye...I never even remember
replacing one. Most plants still have these machines for back-up...just
washed and sitting. No rust still.

So what's the real story here? The statements seem to be conflicting
with real-world experience.

Koz

Me Mine wrote:

Gary has hit the galvanized nail on the head. Any standard
neutralization of HCl will produce NaCl. Consequently, Gary's is right
when advising thorough rinsing. I believe the culprit to accelerated
rusting is the chloride ion. The only way to avoid this is to use a
different acid, i.e. sulfuric acid, H2SO4. I don't know if this is good
for cleaning steel or if it would cause problems with the ensuing
galvanization.

John

In article , Gary Coffman
wrote:



On Fri, 31 Oct 2003 10:33:47 -0800, Grant Erwin
wrote:


Question: can I neutralize HCl with TSP? I know that TSP in solution
is basic. I'm just wondering what happens when you mix TSP with HCl -
obviously, you'd get Na+ ions, H+ ions, PO3-- ions, and Cl- ions.
Sort of like a mix of phosphoric and hydrochloric acids, except for
the sodium. I can't figure it out, my college chem days are long over.


What you get is salt, NaCl. This salt residue will hide in every pore,
crack, and crevice of the part, promoting corrosion. You get the same
thing if you try to neutralize with lye or baking soda. So do *not* try
to neutralize the HCl. Just rinse the part off with plenty of hot water
(chlorides are soluble in hot water). The hotter the water, the better,
because solubility increases with temperature, and the hot water will
evaporate off the part faster, so the part doesn't stay wet long.

Note that the metal will be *extremely* clean at this point, and will
flash rust if you don't immediately oil it or otherwise protect it from
contact with oxygen. That's why the galvanizing guys normally do
the HCl dip and rinse immediately before galvanizing.

Note too that you don't have to worry about the rinse water going
down the drain. You need to use lots of it, and it will dilute any HCl
it washes off the part to harmless levels.



Final question: assuming #2 does NOT work, and further assuming it's
bad news to dump TSP into the sewer, is there any easy cheap way to
neutralize the TSP and make it less environmentally harmful? My
neighbor, no dummy, suggests using it as fertilizer. Does that make
any sense?


Sure, it *is* fertilizer. If you only have a few gallons of the stuff, dumping
it down the sewer isn't a problem either. The environmental concern was
when *everyone* was doing it (laundry detergents with TSP), and the result
was algae blooms downstream of the sewage treatment plant. But a few
gallons is nothing.

For *these* chemicals, dilution is the solution to pollution. That's not true
for some chemicals, or industrial quantities of most chemicals, but it is
fine for disposing of the small amounts of acids and bases used around
the home shop.

Gary



  #22   Report Post  
Bob Engelhardt
 
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Koz wrote:
... The caustic acts as a protectant of some sort and prevents
corrosion rathern than causing corrosion as stated (on mild steel). ...


Actually, what was stated was that using a sodium caustic to neutralize
hydrochloric acid would leave salt which would lead to corrosion. Also,
just using HCl and rinsing it will leave a surface so clean that rust
will begin immediately.

Bob
  #23   Report Post  
George E. Cawthon
 
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Dan Caster wrote:

Grant and Ed,
You might want to check the label on the box to see just what you
have. TSP is not easily procured in New York State. Yes it says TSP
on the box, but the fine print where it lists the ingrediants says
Sodium Carbonate. Sodium Carbonate is cheaper when bought as Sodium
Carbonate.

Here in Washington State, the fine print says contains TSP and Sodium
Carbonate. At least that was what the box at Lowes said. I have not
checked at Home Depot and ACE.

Dan


I have difficulty believing anything else is in a box
labeled as Trisodium Phosphate! If it does, then it
violates laws related to labeling products. I have two
boxes, one old one fairly new that are labeled TSP and both
do not mention any other compound, nor would I expect them
too. Now if you have a product that is labeled as a
cleaner, or a cleaner with TSP, who knows what would be in
it. Recheck the label on the box. If it is labeled as TSP,
it better be TSP.

Anyway sodium carbonate is known commonly as washing soda.
There is no more relationship between sodium carbonate and
trisodium phosphate than there is between TSP and sodium
chloride.
  #24   Report Post  
Old Nick
 
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Default chemistry question

On 31 Oct 2003 17:15:12 -0800, jim rozen
wrote something
.......and in reply I say!:

That swampy smell sure do get around!

BTDT!

And now I am _GLAD_ I use REYNOLDS.

See! The cooking people CARE more than the tansmission people!

And if you put motorbike transmissions in the oven, be
sure to use those Reynolds "roast-in" bags to keep the
90 wt fumes from escaping.

Jim

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================================================= =


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  #25   Report Post  
Old Nick
 
Posts: n/a
Default chemistry question

On Fri, 31 Oct 2003 14:17:45 -0800, "Harold & Susan Vordos"
wrote something
.......and in reply I say!:


I"m no chemistry wizard, but my years of precious metal refining taught me a
few things about hydrochloric acid and metals. I think I'd use a dilute
solution of hydrochloric to clean the steel parts you want to galvanize,
then neutralize the parts with sodium hydroxide (lye).


Producing a salt solution on the metal = rust????

************************************************** ****************************************
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  #26   Report Post  
Grant Erwin
 
Posts: n/a
Default chemistry question

It's really easy to buy fake TSP in Washington too, but if you look
carefully you can get TSP. Which I always do. - GWE

George E. Cawthon wrote:

Dan Caster wrote:

Grant and Ed,
You might want to check the label on the box to see just what you
have. TSP is not easily procured in New York State. Yes it says TSP
on the box, but the fine print where it lists the ingrediants says
Sodium Carbonate. Sodium Carbonate is cheaper when bought as Sodium
Carbonate.

Here in Washington State, the fine print says contains TSP and Sodium
Carbonate. At least that was what the box at Lowes said. I have not
checked at Home Depot and ACE.

Dan



I have difficulty believing anything else is in a box
labeled as Trisodium Phosphate! If it does, then it
violates laws related to labeling products. I have two
boxes, one old one fairly new that are labeled TSP and both
do not mention any other compound, nor would I expect them
too. Now if you have a product that is labeled as a
cleaner, or a cleaner with TSP, who knows what would be in
it. Recheck the label on the box. If it is labeled as TSP,
it better be TSP.

Anyway sodium carbonate is known commonly as washing soda.
There is no more relationship between sodium carbonate and
trisodium phosphate than there is between TSP and sodium
chloride.


  #27   Report Post  
Harold & Susan Vordos
 
Posts: n/a
Default chemistry question


"Old Nick" wrote in message
...
On Fri, 31 Oct 2003 14:17:45 -0800, "Harold & Susan Vordos"
wrote something
......and in reply I say!:


I"m no chemistry wizard, but my years of precious metal refining taught

me a
few things about hydrochloric acid and metals. I think I'd use a

dilute
solution of hydrochloric to clean the steel parts you want to galvanize,
then neutralize the parts with sodium hydroxide (lye).


Producing a salt solution on the metal = rust????

I keep hearing that same response, but how much salt would be in question?
One would have rinsed the parts in clear water, then in a solution of sodium
hydroxide. When the items in question are introduced to the lye solution
the amount of HCL remaining on the parts should be down to next to nothing,
and would most likely already have been neutralized by the iron itself.
If you've not put any steel in HCL, perhaps you should do so to understand
the speed at which it reacts, especially if heated.

Please read the post by Koz, which is in keeping with my personal
experiences as well. I have no argument with the theory of salt being a
by-product, but one might consider the reality of the situation at hand. In
this instance, the part(s) would be protected by the residual lye. It would
be highly unlikely that any salt would have been formed.

Harold



  #28   Report Post  
Dan Caster
 
Posts: n/a
Default chemistry question

Grant where have you found the real TSP?

Dan


Grant Erwin wrote in message

It's really easy to buy fake TSP in Washington too, but if you look
carefully you can get TSP. Which I always do. - GWE

  #29   Report Post  
Grant Erwin
 
Posts: n/a
Default chemistry question

Home Depot. In the paint department. - GWE

Dan Caster wrote:
Grant where have you found the real TSP?

Dan


Grant Erwin wrote in message


It's really easy to buy fake TSP in Washington too, but if you look
carefully you can get TSP. Which I always do. - GWE


  #30   Report Post  
Gary Coffman
 
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Default chemistry question

On Sat, 01 Nov 2003 11:29:23 -0800, Koz wrote:
The caustic acts as a protectant of some sort and prevents
corrosion rathern than causing corrosion as stated (on mild steel).


What we said was that using caustic soda, or baking soda, or any
other alkali metal base to *neutralize* HCl remaining on the steel
from an acid dip produces a salt (in this case NaCl, table salt).
Unless the water is very hot, some of that salt residue will settle
in any pores, cracks, threads, or other feature of the part. *That*
will promote corrosion of the steel.

Obviously, if there is no HCl present, for example your potato
conveyor, adding caustic to the water does not produce salt,
and thus doesn't leave a residue on the steel which promotes
corrosion.

In combination with the starch in the potatos, caustic *should*
produce a carbonate scale on the metal which will in fact offer
some protection from rusting. But scale is what the original
poster is trying to remove, he wants bright metal ready for
galvanizing. So caustic is not advised.

Gary


  #31   Report Post  
John
 
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Default chemistry question

Doesn't the plating shop have a reverse current bath they use for cleaning
parts just before the plating bath?

John



  #32   Report Post  
Eastburn
 
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Default chemistry question

I suspect the plating process won't worry if the part is wet with
a little HCL on it - I suspect there is HCL in the plating and if not,
the zinc will become zinc chloride in short time. And then the Hydrogen
bubbles off in gas form.

Martin
--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder
  #33   Report Post  
Koz
 
Posts: n/a
Default chemistry question

Dang...long day and the HCL thing didn't sink in. Spud plants usually
neutralize with sulphuric or similar during clean-up. BTW, no starch
build-up to be seen on these units. Funny to see em brand new and
painted by the fabricator...paint lasts about 15 minutes

Koz

Gary Coffman wrote:

On Sat, 01 Nov 2003 11:29:23 -0800, Koz wrote:


The caustic acts as a protectant of some sort and prevents
corrosion rathern than causing corrosion as stated (on mild steel).



What we said was that using caustic soda, or baking soda, or any
other alkali metal base to *neutralize* HCl remaining on the steel
from an acid dip produces a salt (in this case NaCl, table salt).
Unless the water is very hot, some of that salt residue will settle
in any pores, cracks, threads, or other feature of the part. *That*
will promote corrosion of the steel.

Obviously, if there is no HCl present, for example your potato
conveyor, adding caustic to the water does not produce salt,
and thus doesn't leave a residue on the steel which promotes
corrosion.

In combination with the starch in the potatos, caustic *should*
produce a carbonate scale on the metal which will in fact offer
some protection from rusting. But scale is what the original
poster is trying to remove, he wants bright metal ready for
galvanizing. So caustic is not advised.

Gary




  #34   Report Post  
Gary Coffman
 
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On Sun, 02 Nov 2003 07:32:26 GMT, Eastburn wrote:
I suspect the plating process won't worry if the part is wet with
a little HCL on it -


I suspect dipping anything wet into molten zinc would get a bit
exciting. We are talking about parts that will be hot dip galvanized,
not plated.

Gary
  #35   Report Post  
Bob Engelhardt
 
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Default chemistry question

Harold & Susan Vordos wrote:
... If you've not put any steel in HCL, perhaps you should do so ...
... my personal experiences as well.
... consider the reality of the situation at hand. ... It would
be highly unlikely that any salt would have been formed.


My PERSONAL EXPERIENCE is this: I found a charge-driving nail gun at
the dump. Nice, but badly rusted. I took it all apart and put it in
HCl. I then neutralized with lye (or maybe TSP). I rinsed really well,
oiled it, and reassembled. I couple of days later I noticed quite a bit
of rust. "Dang!", I thought, "I guess that I didn't neutralize well
enough." I repeated the entire process and was _really_ careful about
neutralizing. It rusted again, badly.

Bob


  #36   Report Post  
Harold & Susan Vordos
 
Posts: n/a
Default chemistry question


"Bob Engelhardt" wrote in message
...
Harold & Susan Vordos wrote:
... If you've not put any steel in HCL, perhaps you should do so ...
... my personal experiences as well.
... consider the reality of the situation at hand. ... It would
be highly unlikely that any salt would have been formed.


My PERSONAL EXPERIENCE is this: I found a charge-driving nail gun at
the dump. Nice, but badly rusted. I took it all apart and put it in
HCl. I then neutralized with lye (or maybe TSP). I rinsed really well,
oiled it, and reassembled. I couple of days later I noticed quite a bit
of rust. "Dang!", I thought, "I guess that I didn't neutralize well
enough." I repeated the entire process and was _really_ careful about
neutralizing. It rusted again, badly.

Bob


Hard to argue with that, Bob. I know from experience that HCL cleaned
steel is quick to rust, in fact it does so as you're rinsing. I may have
to rethink my position.

Harold


  #37   Report Post  
Brian Lawson
 
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Default Rust was chemistry question

Hey Bob,

Maybe that's why it was in the dump! I've got some stuff, in
particular a cheapish brand of center drills, that rust anytime after
their first use, while sitting in a nice Kennedy box with all sorts of
other items that are not rusting. Can't stop it. And it's a rust
almost like satin anodizing, more like a light coating or a stain
than something heavy. I think it's just the steel make-up. It's more
like an "oxidation" than a "rust". Maybe from the heat of cutting?

Anyway, we're going to see about rust come this Tuesday, when my
unprotected machines arrive in the semi-trailer truck, where they've
been sitting since early June. They were supposed to only be there
for a month of warm and dry weather, but it's taken 3-1/2 months for
the builder to complete my new "shed". I'll be unloading in the fall
here. Drizzly rain this morning, and light fog for a few hours early
everyday now. Oh goodie! Wish me luck!

Take care.

Brian Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
On Sun, 02 Nov 2003 07:48:27 -0500, Bob Engelhardt
wrote:

Harold & Susan Vordos wrote:
... If you've not put any steel in HCL, perhaps you should do so ...
... my personal experiences as well.
... consider the reality of the situation at hand. ... It would
be highly unlikely that any salt would have been formed.


My PERSONAL EXPERIENCE is this: I found a charge-driving nail gun at
the dump. Nice, but badly rusted. I took it all apart and put it in
HCl. I then neutralized with lye (or maybe TSP). I rinsed really well,
oiled it, and reassembled. I couple of days later I noticed quite a bit
of rust. "Dang!", I thought, "I guess that I didn't neutralize well
enough." I repeated the entire process and was _really_ careful about
neutralizing. It rusted again, badly.

Bob


  #38   Report Post  
jim rozen
 
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Default chemistry question

In article , Gary Coffman says...

What we said was that using caustic soda, or baking soda, or any
other alkali metal base to *neutralize* HCl remaining on the steel
from an acid dip produces a salt (in this case NaCl, table salt).


I think the standard, visceral demonstration for this is
the one typically done in a beginning chemistry class.
The instructor demonstrates some NaOH solution, how it
will be terribly causting and then the same with some
concentrated hydrochloric acid, again a piece of metal
or whatnot dropped in the beaker,

Then you mix the correct proportions and the result is
then imbibied in front of the audience. Salt water,
see?

Almost as good as the milk carton full of oxy hydrogen
mix from electrosis of water...

Jim

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  #39   Report Post  
Old Nick
 
Posts: n/a
Default chemistry question

On Sat, 1 Nov 2003 18:17:53 -0800, "Harold & Susan Vordos"
wrote something
.......and in reply I say!:

I keep hearing that same response, but how much salt would be in question?
One would have rinsed the parts in clear water, then in a solution of sodium
hydroxide. When the items in question are introduced to the lye solution
the amount of HCL remaining on the parts should be down to next to nothing,
and would most likely already have been neutralized by the iron itself.


But if you have removed the HCl to the point where the salt will not
matter, what is the point of "neutralising" it with the lye?

Smart-sounding question, but genuine. I have always used simple
rinsing and then oil (WD40 or whatever) if needed rather than NaCl,
because of the salt argument.

_Does_ the lye protect the steel in any way?

If you've not put any steel in HCL, perhaps you should do so to understand
the speed at which it reacts, especially if heated.


I have done it. Yes it rusts anyway if left.


Please read the post by Koz, which is in keeping with my personal
experiences as well. I have no argument with the theory of salt being a
by-product, but one might consider the reality of the situation at hand.


Actually burying the steel in lye, as those conveyors apparently are,
is quite different from having dipped them for a short while and then
left them out to air.

In
this instance, the part(s) would be protected by the residual lye. It would
be highly unlikely that any salt would have been formed.



************************************************** ****************************************
Until I do the other one,this one means nothing
Nick White --- HEAD:Hertz Music

remove ns from my header address to reply via email

!!
")
_/ )
( )
_//- \__/
  #40   Report Post  
Ted Edwards
 
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Default Rust was chemistry question

Brian Lawson wrote:

here. Drizzly rain this morning, and light fog for a few hours early
everyday now. Oh goodie! Wish me luck!


Get a spray can of CRC 3-36 NOT WD-40 and give the machines a light
spray before taking them out of the truck. Good luck.

Ted

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