chemistry question

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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Grant Erwin wrote:
<snip>

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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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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the
could
whatever,
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
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it.
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)
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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
================================================= please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com =================================================
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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!

****************************************************************************************** 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
!! <") _/ ) ( ) _//- \__/
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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
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We have both products here in NJ, Dan. The stuff I have is straight TSP.
Ed Huntress
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Yes, but the downside on this is, you also have Secuacus! :^)
Jim
================================================= please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com =================================================
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Ed Huntress says...

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
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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.

LOL.
Jim
================================================= please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com =================================================
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Dan Caster wrote:

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.
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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:

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Grant where have you found the real TSP?
Dan

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Home Depot. In the paint department. - GWE
Dan Caster wrote:

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On Sat, 01 Nov 2003 22:44:48 GMT, "George E. Cawthon"
<SNIP>

I have a tub of Red Devil brand cleaner labeled TSP/90. The "TSP/90" is printed in a bold font about 3/4" tall. Above that, in a much smaller and lighter font, it says "phosphate free". The ingredients are "sodium metasilicate". The instructions for use say it is "a trisodium phosphate substitute".
Any that spends 30 seconds reading the label would know that this is not real TSP, but I could see where someone in a hurry could mistake it for the real thing.
R, Tom Q.
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Tom Quackenbush wrote:

True. But TSP/90 sounds like 90% TSP, so I would think this is a near case of labeling fraud.
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I have difficulty with it too, but it happens. You used to be able to buy pure Calgon at the super market, but all the boxes I have looked at for some years say Sodium Carbonate and Calgon.
As you say Sodium Carbonate is washing soda, and as such it is milder than TSP but used for many of the same things.
Dan

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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
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