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Slightly OT: How to store or dispose of muriatic acid?

awake

Titanium
Joined
Jan 24, 2006
Location
Angier, North Carolina
I have searched and searched through the General New and General forums, thinking surely this question has been answered before, but all I have found is warnings not to store it inside. Actually, that's why I was searching -- I remember seeing a gazillion posts on here warning of the dangers of storing muriatic acid inside the shop, as "even a sealed container" can leak fumes and cause all sorts of rust nightmares.

Unfortunately, I find myself needing to use a small amount of muriatic acid ... and the smallest amount I can buy is 1 gallon. I will use about 1 pint at most, so what do I do with the rest? I surely do not want rust problems!!

The obvious answer seems to be: store it outside -- but I'm concerned about two things. First, how far outside is "safe" for the house? And second, I'm concerned about children investigating or it getting knocked over.

Any suggestions??
 
Yup, give it to a concrete guy or a mason.

You're correct. Muratic acid fumes have a way of escaping even a tightly sealed container and causing endless rust. You have to keep it out of doors away from metal. If you have to store it put it in a plastic shed or storage enclosure and give the fumes a concrete block to nibble on. The cement in concrete will neutralize muratic acid fumes to calcium chloride; itself a very corrrosice salt but the calcium in the cement does blot up the fumes.

Alternatively set up out of doors downwind from structures and anything metal. Pour the acid into a plastic bucket. Using a wood stick gradually stir in powered laundry detergent until it quits foaming. Select a powdered laundry detergent that is predominantly soda (sodium carbonate) plus degergents, sequestering agents, perfume, etc. The soda reacts with the acid to form table salt and CO2. The fully neutraized miratic acid is essentially saltwater. You can pour it down the sink. No EPA disposal necessary.

Acid once used as a pickle has metal salts in it. You can neutralize it but the metal salts remain. You really should EPA dispose it but small quantities? Let your conscience be your guide.
 
Related question

Okay, sounds like option 1 is to find someone to take it (best option, since I hate to waste it); backup option is to neutralize it. For the latter, what precautions do I need to take? I assume this will generate some heat?

A related question: the reason I need the muriatic acid is to make some cupric chloride to etch PC boards. This is way cheaper than ferric chloride, and can be renewed again and again. So far, so good. But then there is the question of storage: Does anyone know if cupric chloride will cause the same rusting problems as muriatic acid?
 
Umm, how ya gonna dispose of the CuCl solution when you are done with it?
And don't say, pouring it down the drain.....

Suggestion: If you are making the boards from hand-fabricated artwork (acetate
and taped lines) consider using some version of a circuit board software that
gives out gerber files (gerber files, G codes, same thing more or less....) and
then emailing the files to a board house.

There are lots of board houses, you send 'em files, they ship ya boards. Soon.
Cheap. No chemicals need cross your threshold. Just a thought.

Jim
 
Here is the deal with Muratic acid. The gallon jug says, 40% Hydrochloric acid, 60% water right on the label. When you remove the cap it makes a lot of fumes and when you pour it from the jug to another container you get even more fumes. If you do this inside it will choke the heck out of you. The fumes will turn every piece of metal in the building ORANGE with rust.

Use the acid out side and be sure to stand on the up wind side. If it is a hot summer day the fumes will collect on your sweety body and you will get a mild acid burn. After you have used the acid put the cap on tight and store it under the work bench. Make darn sure the container never gets a hole in it and the cap stays on tight.

I have a gallon of Muratic acid it has been in my work shop for 15 years. I never remove the cap inside the building. It is great for cleaning rust off of parts and removing zinc coating on metal before welding. It will clean brass and copper like brand new in just a few seconds. Be sure to rinse well with water.

Sulfuric acid and Muratic acid are both used as drain cleaner. It works wonders on a urinal cleans it right out. For those that won't flush after taking a leak in the toilet Muratic acid will remove the calicium deposit left in the toilet.

Mix the acid with aluminum in a large glass jug. Pipe the gas through a rubber hose into a container of Lime. The Lime will remove unwanted other gasses like ammonia, ,moisture, etc. and you then have pure hydrogen gas. The gas can be used to make lighter than air balloons or a Hindenburg.

After high school I worked for a company that pumped 100% Hydrochloric Acid down into oil wells. Over a number of years rust would clog up the inside of the oil well casing = steel pipe. The acid would remove the rust and the oil would flow again. Schlumberger would drop well piecering guns into the well to make more holes in the casing to increase oil flow.
 
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I don't know about your area, but here homeowners have a hazardous waste station to bring darn near anything. See if there is program in your area, be it run by the state or county.
Tom
 
Pour it in the drive way and rinse it down with water??? Seems like everyone is making a big deal here. If you want to work hard you can mix it with lye and make salt water.

I'm pretty sure you can get the acid at the hardware store in a 1qt. bottle.
 
Common muriatic acid is about 10% max hydrochloric acid, not 40%.

Concentrated hydrochloric acid is usually kept at a concentration of less than 40% unless there's some compelling reason to go to a higher concentration. Even a 25% solution of hydrochloric will make common commercial muriatic look like lemon juice in comparison.
 
Common muriatic acid is about 10% max hydrochloric acid, not 40%.


Check the MSDS here:

http://www.hasapool.com/msds/110.pdf

The bottle I have on the shelf is also marked 31.45%.

Concentrated hydrochloric acid is usually kept at a concentration of less than 40% unless there's some compelling reason to go to a higher concentration. Even a 25% solution of hydrochloric will make common commercial muriatic look like lemon juice in comparison.

AFAIK, you can't get hydrochloric acid in a concentration over ~35% or so because that is the saturation point for HCl in water.

HCl is a gas, hydrogen chloride. "Hydrochloric Acid" refers to a solution of HCl in water.
 
We had an old lawyer's type metal bookcase at the toolmaker's shop in Williamsburg. that's a metal,or wood,cabinet about 12"x14"x3',it has a glass door that slides down from the top.

We kept quart bottles of muriatic,sufuric,and nitric acid in there. Somehos I had no corrosion problems in the shop. The cabinet itself showed some corrosion,but we used it for 20 years.

When I was a teenager,we had a bare bones garage.I noticed the chrome plated wrenches rusting. kept wiping them off. One day,I noticed the 1 pint,never opened plastic CUBE of muriatic acid across the room. I poured it out ,the rusting stopped.
 
I used to keep my gallon of muriatic acid next to my other metal gallon containers. Noticed they were rusting, and shortly after that read about people having trouble with it even in a 'closed' container. So I bought a white plastic 5 gallon bucket and lid from Home Depot and put the gallon jug in it and moved it outside. I figure the 5 gallon bucket keeps the sun from deteriorating the plastic jug, and keeps nosey people away from it.

Scott
 
Umm, how ya gonna dispose of the CuCl solution when you are done with it?
And don't say, pouring it down the drain.....

Suggestion: If you are making the boards from hand-fabricated artwork (acetate
and taped lines) consider using some version of a circuit board software that
gives out gerber files (gerber files, G codes, same thing more or less....) and
then emailing the files to a board house.

There are lots of board houses, you send 'em files, they ship ya boards. Soon.
Cheap. No chemicals need cross your threshold. Just a thought.

Jim

Jim, the basic answer is that I don't plan to be done with it for quite a long time. :)

The two things that attracted me to using CuCl is that 1) it is cheap, and 2) it is renewable. With FeCl, which I've used before, it is pretty much one use and you're done. With the CuCl, you can bubble air through it and "renew" it. Given the rate at which I make PC boards (I'm on my 4th in the last 25 years :)), I expect I might not ever have to dispose of the CuCl. In any case, if and when I need to dispose of it, I most certainly will not pour it down the drain!!

I am indeed using software (Kicad) to generate the artwork, and it can generate Gerber files -- but "cheap" is a relative term. For the size board that I need (roughly 3" x 5"), the cheapest price I can find for a board service is around $80 for one board. Sure, if I buy 100 boards they're only a few bucks each ... but I only need one board. My total cost to make this board is around $10, and this is strictly for hobby purposes, and I'd rather save the bigger expeditures for buying tooling, and ... well, you get the idea!

BTW, the first board I ever made, 25+ years ago, was indeed hand-fabricated artwork ... and I mean HAND fabricated, as in using a resist-ink pen -- at the time I didn't know that taped lines and such even existed. To my great surprise, it worked, though in retrospect it probably shouldn't have. It was an interface board to connect a video digitizer to an Apple II+. :)
 
We had an old lawyer's type metal bookcase at the toolmaker's shop in Williamsburg. that's a metal,or wood,cabinet about 12"x14"x3',it has a glass door that slides down from the top.

We kept quart bottles of muriatic,sufuric,and nitric acid in there. Somehos I had no corrosion problems in the shop. The cabinet itself showed some corrosion,but we used it for 20 years.

When I was a teenager,we had a bare bones garage.I noticed the chrome plated wrenches rusting. kept wiping them off. One day,I noticed the 1 pint,never opened plastic CUBE of muriatic acid across the room. I poured it out ,the rusting stopped.

I'm intrigued with the possibility that it might be possible to store it "safely" (as in without rusting out the garage) after all. In addition to gwilson, has anyone else successfully stored muriatic acid long-term inside a shop without rust problems?

applescotty, using a 5-gal bucket is a good idea that I might adopt. How far outside (how far away from buildings) have you stored it?
 








 
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