What is the best rust remover soak?

spdway1

spdway1

Well-known member
What is the best rust remover soak? I do not want to sandblast.
The parts have some heavy scaling. Thank you.
 
I've used 2 or 3% vinegar out of the bottle on nuts, bolts, cast iron sediment bulb and am quite surprised at the good results. I let it soak a day or so depending on the rust build-up. I've used EVAPORUST, it worked but I did see some metal was removed. Oh, I've read one part molasses and 10 parts water also works slowly. It's the same chemical reaction of EVAPORUST. Watch YOU-TUBE channel. LRF
 
I usually do the previous two posts in order.

Electrolysis removes/reverts the rust - but leaves an "optimal" surface for "re-rusting."

Every chemical bond which was red rust before is now "black rust" which, if you're fast you can paint immediately to "seal it in." But each of those bonds is now waiting to re-form red rust even under that paint.

Using "Prep & Etch" converts each of those bonds into something else - which can be painted AT YOUR LEISURE - up to a point. It provides another integral layer of protection to the bare chemical bonds.

I had a small Worthington steam pump which I put through the electrolytic bath. Nice because electrolysis removes grease, paint, EVERYTHING but the ferrous metal. I then quickly followed with Prep&Etch. The pump then sat for two years before I got back to it to paint it with engine enamel. No change in that time - a dull grey coating.

Right now I have a Model A wheel which has been through the process. It's sitting in my garage since about May - maybe just a smidge of rust now.

It appears that "Prep N Etch" is now discontinued, replaced with another product by Klean Strip, which looks the same, acts the same, but is aimed at conditioning concrete for painting. https://kleanstrip.com/cleaning-and-paint-prep/concrete-metal-prep/

For my electrolytic bath I used a weak solution of lye - available at many hardware stores as "Crystal Drain Cleaner." This is 100 percent sodium hydroxide. Don't use "Drano" as it is heavy in sodium hydroxide, but also contains aluminum dust - which "heats" under the chemical action - a heat you don't want and might get burned from.

My lye solution I mix to the point where - with the power off - I can reach into the bath with my bare hand without injury or sensation. One's hand gets MARVELOUSLY clean in the bath.

For the charge I use a Sears Craftsman Battery charger 0-8 amps. Amps I try to run under the "trip point" of the meter. On either 6v or 12v - whatever it takes.

And the bath operates mainly "line of sight" - so rotate your parts daily. Expect 3-4 days to complete a part. Longer is better.

Joe K
 
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That concrete formula you mention Joe is phosphoric acid. Ask any engineer that specializes in concrete construction. They use that because sulfuric acid creates the fumes and the workers cleaning the concrete dislike that.
 
Spdway,

Go down to your local Ace Hardware or similar and pick up a container of Wood Bleach. (Oxalic Acid)
It comes in powder form.

Mix it with water and let your part soak in that for a couple of days. Works very well. I've been using it for years on rusted parts.
Also if you have old spark plugs that are rusty and the porcelain is stained soak them in it too. Takes all the rust off and makes the porcelain look like new.
 
Gene F said:
That concrete formula you mention Joe is phosphoric acid. Ask any engineer that specializes in concrete construction. They use that because sulfuric acid creates the fumes and the workers cleaning the concrete dislike that.
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More on Phosphoric Acid/Prep & Etch/Concrete & Metal Prep.

https://www.jalopyjournal.com/forum/threads/rust-removal-using-phosphoric-acid-help.637951/

There are some "fumes" from the use of Prep & Etch. I might even characterize them as "nasty." But ventilation helps as does a quick rinse with warm water.

Joe K
 
A cheap rust remover muriatic Acid, been using it to clean sheet metal for 20 years. can get it at most hardware stores for around $10 a gallon. get a plastic tub or some like container and add in till water turns a little color. Just be careful and use your PPE gloves and eye protection. Soak for day or more depending on how deep the rust is, was off with clean water. While your at the hardware store pick up a box of powder mix TSP put this in a spray bottle and spray down your clean metal ,this will keep it from flash rusting. "see picture" Just take care when using an acid it will burn.
 

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I have a 5 gallon bucket of water and muriatic acid mixture that I've had under my work bench for many years. I use it mostly to remove the plating off of nuts, bolts and washers that I want to paint or weld on. Removes the plating in a matter of less than a minute in most cases.
It does work well as a rust remover. However it will eat metal down to nothing if you leave it in there too long.

Found this out the hard way while removing rust from an old style pipe wrench that was my great uncles. Sadly when I did remember it was soaking it was too far gone.
 
I used various homebrew recipes before finding EvapoRust. Used it for a while but have now switched to Rust911. $80/gal but still way cheaper than ER given 15:1 dilution. For me it works faster/better and last longer than ER.
 
Oldbluoval said:
MW
How do you dispose of muratic acid??!!
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https://en.wikipedia.org/wiki/Hydrochloric_acid#References

Gaseous HCl was called marine acid air. The name muriatic acid has the same origin (muriatic means "pertaining to brine or salt", hence muriate means hydrochloride), and this name is still sometimes used.[1][9] The name hydrochloric acid was coined by the French chemist Joseph Louis Gay-Lussac in 1814.[10]
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IIRC, trade muriatic acid is similar to the Hydrochloric Acid of your High School Chemistry Class, but a lesser "dilution" adapted to direct application to masonry.

Mix with any "base" material. Lime works pretty good and is cheap.

When no longer bubbling, (i.e. "neutral) you pour it on your lawn.

(The point of putting lime on your lawn is to neutralize "acid rain" and promote a healthier growing environment.)

Joe K
 
I have used Rust 911 for many years with very good results. It comes in concentrated form and is biodegradable. Much cheaper than Evaporust. I buy it online direct from the manufacturer.

Chris W.
 
Electrolysis is best in my opinion. Buy a cheap voltage controller on Amazon. No chemicals to deals with. Set up and let er rip. Like someone said earlier, be prepared to dry and oil it immediately upon removal or go right to paint.

Don’t use electrolysis on stainless or chrome.

I always run mine outside. No reason for indoor risks of fire while the unit is running and unattended.

Biggest I have is a 100 gal tank, I’ve done engine blocks, trans cases, etc. it gets all the nooks and crannies cleaned. As the liquid warms, it also removes grease and old paint that has rust under it which other store bought rust removers don’t do.

Good luck.
 
Biggest I have is a 100 gal tank, I’ve done engine blocks, trans cases, etc. it gets all the nooks and crannies cleaned. As the liquid warms, it also removes grease and old paint that has rust under it which other store bought rust removers don’t do.
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I have done a Model A engine block. I have heard warnings that electrolysis can "loosen" the bond of babbitt in the engine block. I can't say I saw a sensible loosening, but the babbitt appeared "dull" in appearance, much like the cast iron machined surfaces tend to look. That engine was headed for a re-babbitting anyway.

This summer's project was a couple of Model A wheels, heavily rusted (paint all gone) A bit rough but paint will fill in the pits somewhat. For this I built a wooden box about 2' square and 12" deep, and lined it with a sheet of 6 mil plastic. Folding the interior corners of the plastic brought to mind my military experience of "hospital corners" - in reverse. "Line of sight" on those wheels. They were flipped at least four times per wheel.

Electrolysis WILL loosen rusted together pieces. My most heavily rusted together parts ALWAYS head into the bath first for a couple of days prior to PB Blaster, heat, or armstrong loosening.

Electrolysis did a nice job on the interior pumps and parts of the Monitor Civil War battleship. Larger parts of which have been recovered and are now being conserved.

https://sanctuaries.noaa.gov/news/aug16/restoring-the-turret-of-the-uss-monitor.html

Joe K
 
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There are a few opinions about what's the best, but I would recommend Evapo-Rust. According to the manufacturer you can reuse it, but I guess that's up to you ;)
 
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