Cleaning mill scale with vinegar question??

[torker]

Hey guys!
I'm cleaning some mill scale with vinegar (duh) and I'm tired of the usual wait. I'm wondering...if you boil or heat the vinegar...would this speed up the process?
How bout what kind of dangerous gas would I then produce that would kill me in minutes?
Would "hot" vinegar work better on the somtimes stubborn spots you sometimes get?
Thanks!
Russ

[Forrest Addy]

Vinegar is a pretty weak acid. It will work as a mill scale pickle but it takes a while, like an aeon I suggest you use phosphoric acid as in Jasco Metal Prep and similar products. A 5 gallon pail and a 5 or 10 to 1 dilution of the metal prep is all you need for stuff no bigger than you head. Scale according to your work.

Stronger acids like muratic and sulfuric are quicked but there's the hazard and disposal problem and the fumes can generate rust like you can't believe.

Phosphoric acid can be neutralized with powdered laundry detergent and flushed. The constituent in the reneutralized phoric acid pickle are sodium phosphate, Iorn phosphate, iron oxide flakes. And traces of manganese and other phosphate salts all acceptcale to the effluent stream - at least they are around here. YMMV

[torker]

Thanks Forrest! Umm...what kind of acid is battery acid?
I have about 7 gallons of it that I have to get rid of. Maybe I could use that?

[rotate]

Thanks Forrest! Umm...what kind of acid is battery acid?
I have about 7 gallons of it that I have to get rid of. Maybe I could use that?

I hope you're being facetious. Battery acid is a strong sulfuric acid and it's nasty to handle. Be very careful when handling it. I have know a guy who has permanent scar on his face just because some it splashed.

I once had to dilute battery acid with water and even after 1 to 100 dilution it was still discolouring copper parts.

[torker]

Nope.. I wasn't being what you said I'm serious...why not dilute the battery acid and use it?
I realize you'd have to be pretty darn careful with it.
I have no idea where to get a 5 gallon pail of any kind of acid around here.
I really love the finish you get after using vinager to remove mill scale but it takes too long.
I have a 30X50 pole barn with open sides that I could keep a big plastic tub with some acid mix in it.
Ah...prolly not a good idea..
Russ

[derekm]

Nope.. I wasn't being what you said I'm serious...why not dilute the battery acid and use it?
I realize you'd have to be pretty darn careful with it.
I have no idea where to get a 5 gallon pail of any kind of acid around here.
I really love the finish you get after using vinager to remove mill scale but it takes too long.
I have a 30X50 pole barn with open sides that I could keep a big plastic tub with some acid mix in it.
Ah...prolly not a good idea..
Russ

Of course diluting the acid will work.. (grand mother suck eggs mode)
add acid to the water not the other way around. You dont get fumes off the very dilute acid. Only use concentrations that produce a gentle reaction. test it with a small quantity of dilute acid and a small piece of metal. Have a water hose nearby to flush any splashes off.
do you know the concentration of the battery acid?


Dont smoke near by when the metal is reacting ~ Hydrogen gas is produced we dont need a Torker # hindenburg (yes I know it was the AL~Fe2O3 reacting)

[PTSideshow]

http://www.derustit.com/

A little pricey but it doesn't have the drawbacks the others have.
I haven't tried it yet as I was just given the information the other day.

[Duffy]

Torker, battery, (AKA sulphuric,) acid does not produce noticeable fumes. Its concentration, depending on the state of charge of the batteries when you drained them, will be about 30%. Add the acid, SLOWLY with stirring, to twice as much water to give a fairly vigorous pickle solution. Suggest that you get a plastic 45 gal drum and cut it in half for a sturdy non-corroding "pickle barrel." Yes the acid will work faster if you heat it. Chemical reaction rate doubles for every 10 degrees C that the temperature increases. To dispose of the spent acid, go to your nearest garden center and buy a bag of ground limestone or marble chips, (they are the white rocks people like to use as a decorative touch.) Add SOME and leave it, stirring occasionally, until the foaming stops. You will be left with a sludge of calcium and iron sulphate, which is harmless but ugly. Put it where you cant see it.
Since you evidently live in a "chemical desert," you may HAVE to use a hydrochloric acid pickle, but the fumes ARE corrosive. Go to your local CTC or Home Hardware, (I KNOW that you dont have a Home depot, cranbrook is too small.) Buy a gallon of Muriatic Acid-it is in the paint section and is used for etching concrete floors before painting. It is about 30% concentration, so dilute it by adding one part acid to two parts water, (AGAIN slowly with stirring, AND hold your breath-the stuff makes you choke.) This will have to be neutralized after use because of the corrosive fumes. Use the "old limestone/marble routine" as before-the end result will be a SOLUTION of calcium and iron chloride, with very little sludge and it too is harmless. Both of these wastes will kill plant life, simply because of the salt content. If you have a big gravel driveway/turnaround, THAT is your "waste disposal site."
Here endeth the lesson!

[rowbare]

Nope.. I wasn't being what you said I'm serious...why not dilute the battery acid and use it?
I realize you'd have to be pretty darn careful with it.
I have no idea where to get a 5 gallon pail of any kind of acid around here.
I really love the finish you get after using vinager to remove mill scale but it takes too long.
I have a 30X50 pole barn with open sides that I could keep a big plastic tub with some acid mix in it.
Ah...prolly not a good idea..
Russ

Battery electrolyte is sulphuric acid.

Make sure you keep lots of baking soda around if you do use it. Use it to neutralize spills and old acid. Wear long rubber gauntlets and a face shield at all times. Have an eye wash station handy too... You can hardly be too careful with this.

bob