Cleaning metal with Muriatic Acid

[C96]

Muriatic Acid, has it lost its OOMPH!

This is a cut n paste from “Free Parking” as not sure where to post this.

Since I’m cleaning metal with it, I’m going to consider it as a tool… Lol

Many times I have used muriatic acid to clean rust from metal and it has worked very well. Recently I’ve noticed it just doesn’t seem to pack the punch as it once did.

Example, I have always used it to clean rust off the horseshoes (the game shoes) when they have been left outside for months. I would just put them in a plastic pan and cover them with muriatic acid and let sit for an hour or so. When I pull them out they look like new. Now when I do this, they don’t seem to fizz much and even after 3-4 hours of soaking they still are no way near clean of rust.

The product is new and just recently purchased, so it’s not old, or become degraded from sitting around.

Are there different qualities that vary from one manufacture to the next? If so, what to look for on the label to insure the best quality product?

 

[vasili]

do you have any photo of metal cleaned with muriatic acid
thank you

 

[FMC]

check the concentration, its not all the same

 

[bwringer]

"Muriatic Acid" is just ye olde fashionned name for plain old HCl,Hydrochloric acid.


I've always hated the imprecision of chemical names from the 17th century...


Anyway, it's certainly possible that the HCl you used in the past was a higher concentration than what you're using now. Just to choose at random, there are two different types of HCl listed under "Muriatic Acid" on the Lowe's web site -- the regular formula is 31.45% strength and the "Next" formula (advertised as "90% Less Fumes!") is 15.725%.

Well, yeah, you're going to have less fumes when you water it down -- not sure how adding water is some sort of product breakthrough...


In any case, it's not always a good idea to clean metal with acid. That's a separate debate, I guess. You're probably pretty safe with horseshoes used for throwing.

 

[ken w.]

I bought a gallon at Home Depot to remove the rust from a snow blower fuel tank. I had to dilute it with water. It was marked low fume. It worked pretty good. I noticed that when I went to dip a bench vise I was restoring that it seem to take forever to get the metal bare. Before I dipped it I wire wheeled it and degrease it. I dipped it single part at a time. It did not fizz very much.
It took 2 days in the bucket for it to come clean. Other times before when I used Muriatic Acid it seemed to work faster and bubble a lot more.It also had more fumes. I like the old formula better.

 

[jkwilson]

Around here Home Depot only carries the diluted stuff.

 

[fsae0607]

Get some from a pool store. It's usually higher concentration than the stuff you get at big box stores.

 

[C96]

I bought a gallon at Home Depot to remove the rust from a snow blower fuel tank. I had to dilute it with water. It was marked low fume. It worked pretty good. I noticed that when I went to dip a bench vise I was restoring that it seem to take forever to get the metal bare. Before I dipped it I wire wheeled it and degrease it. I dipped it single part at a time. It did not fizz very much.
It took 2 days in the bucket for it to come clean. Other times before when I used Muriatic Acid it seemed to work faster and bubble a lot more.It also had more fumes. I like the old formula better.

↑↑↑ This is exactly what I’m talking about. ↑↑↑

Around here Home Depot only carries the diluted stuff.

Get some from a pool store. It's usually higher concentration than the stuff you get at big box stores.

Never was a problem before using the HD or Lowes stuff, I guess things have changed.

Could it be the feds have made the manufactures tone it down for the general public and the good stuff only available for industry use?

 

[wrenchguy]

Get some from a pool store. It's usually higher concentration than the stuff you get at big box stores.

+1, use it full strength a couple hours, put a lid on it tight if needed, dump it, inspect it, do again if needed. don't forget it!!!!!

 

[shanny19]

Get some from a pool store. It's usually higher concentration than the stuff you get at big box stores.

Or a brickyard/masonry materials supplier. Real muriatic acid.

 

[C96]

Anyway, it's certainly possible that the HCl you used in the past was a higher concentration than what you're using now. Just to choose at random, there are two different types of HCl listed under "Muriatic Acid" on the Lowe's web site -- the regular formula is 31.45% strength and the "Next" formula (advertised as "90% Less Fumes!") is 15.725%.

Your right and that explains what I have experienced trying to clean this metal. Prior to this last purchase I must have been using the 31.45% that worked great.

I checked the label of this new purchase and the bottle says 14.50% WTF because this works like ****! Never again, was a total waste of time.

Thanks for the heads-up; you can bet I’ll look at the labels very close now that I know what to look for.

 

[abachman]

I get mine at the local True Value Hardware store and it is still full strength

 

[Alan Douglas]

I bought some recently and found the diluted "safe" stuff cost twice as much.

I'm a little puzzled about using it to remove rust however, since just the vapors from a sealed bottle will cause rust on any exposed steel in the area. I'm storing my leftover acid outdoors in a lean-to.

 

[fsae0607]

Yeah I notice a difference!

I'm at work right now and can't check the % concentration, but the muriatic acid I get from Lowe's/HD doesn't nearly fume as much as the stuff I get at the mom & pop pool store by my house! I really have to hold my breath when pouring it in my pool

 

[kazlx]

Less fumes means more water haha. There's no way to get around strong acid that doesn't fume as much. The pool supply places are pretty consistent. I'm sure the HD stuff *****.

 

[Dust Devil]

I use muriatic acid to clean aluminium that is melted/galled onto cylinder walls.

It is strong and taking a big whiff of it is not a good idea.

 

[C96]

I bought some recently and found the diluted "safe" stuff cost twice as much.

I'm a little puzzled about using it to remove rust however, since just the vapors from a sealed bottle will cause rust on any exposed steel in the area. I'm storing my leftover acid outdoors in a lean-to.

Yes Alan, it’s very corrosive, but cleans metal nicely. You must be very careful handling it and be in a well ventilated area, best outside. I’ve been using it over the years to clean rusted metal parts with great results. Basically no work needed, just let the parts soak and viola! Like new ready to paint or…

Just make sure not to forget about it, depending what you’re soaking, when you come back it might be completely dissolved!

I just accidentally picked-up the weaker stuff unknowingly and couldn’t understand why the parts weren’t getting clean. Now I know thanks to the members here on GJ. Didn’t realize the different varieties Muriatic Acid is available in.

Any of you using this please be very cautious when doing so.

 

[Alan Douglas]

I usually use electrolysis for rust removal. For instance this locomotive was just a shapeless lump of rust when I dug it up in the back yard, but I thought I saw the edges of four wheels so I tried cleaning it.

 

[Waggoner72]

I used muriatic acid the other day to clean the inside of a rusted motorcycle gas tank. Just the acid available at Home Depot, worked good.

Now a question for y'all, what do you use to neutralize it so the metal doesn't flash rust back since it's exposed?
Such as in my case where you can't paint it to prevent it. I was told let it soak in navel jelly, which I did, but it ended up flash rusting on me. Any ideas?

 

[abk241]

I used muriatic acid the other day to clean the inside of a rusted motorcycle gas tank. Just the acid available at Home Depot, worked good.

Now a question for y'all, what do you use to neutralize it so the metal doesn't flash rust back since it's exposed?
Such as in my case where you can't paint it to prevent it. I was told let it soak in navel jelly, which I did, but it ended up flash rusting on me. Any ideas?

There are a few products out there to coat the inside of mc tanks and are specifically made to prevent rust.
I can't recall the name of the one I used a long time ago - just ask at the parts counter of your mc dealer.

 

[Waggoner72]

There are a few products out there to coat the inside of mc tanks and are specifically made to prevent rust.

I can't recall the name of the one I used a long time ago - just ask at the parts counter of your mc dealer.

Yea I knew about those but was wondering if there was any household stuff or Home Depot products like the navel jelly.

 

[TonyCH]

Now a question for y'all, what do you use to neutralize it so the metal doesn't flash rust back since it's exposed?
Such as in my case where you can't paint it to prevent it. I was told let it soak in navel jelly, which I did, but it ended up flash rusting on me. Any ideas?

I've been told baking soda (Sodium bicarbonate, NaHCO3) will neutralize muriatic acid. I would think mixed with water would work best.