Muriatic acid for cleaning rusty car parts.

A few years ago, I discovered Muriatic acid works extremely well for cleaning RUSTY engine parts.

Quick notes on usage.

Follow the directions on the bottle.

Wear eye protection and rubber gloves.

Work outdoors with proper ventilation.

DO NOT USE ON ALUMINUM PARTS. They will dissolve before your eyes.

Use a piece of steel wire as a handle for dipping the parts into an acid bath. I use mechanics wire.

Here's the product I use. Acid Magic is the User Friendly acid for cleaning.



Rusty part before cleaning. This part of an EGR tube assembly.



Dipping the parts in the acid solution. The chemical reaction will start to bubble away the rust like a seltzer tablet in water.



The acid solution will change color as it removes the rust and cleans the parts.

Just be patient and let it do its work.



Newly cleaned parts. Be sure to rinse the newly cleaned parts in water and spray with Fluid Film (or similar) to prevent rust from returning.

 

Also know that Phosphoric Acid will chemically change rust from iron-oxide to iron-phosphate. The result is a great primer. (Rust will come back without further protection (i.e. paint)). Phosphoric acid is the principle ingredient in Naval Jelly.
I can usually find it called "Ospho" at most any hardware store.


It is an acid so same precautions that @CS_AR named, apply.
It is also an ingredient in Cola!

 

Oxalic acid (i.e. wood bleach) is also a good choice to remove rust if the part is painted or plated. It will remove the rust only and won't dissolve or discolor paint, plating or substrate. It doesn't work as fast as muriatic acid (i.e., hydrochloric acid), but it is less caustic and safer to use. You do have to submerge the part in the acid and leave it for hours or a day at a time to get things to work. See link below for examples of how it works:

https://www.jalopyjournal.com/forum/threads/tech-using-oxalic-acid-to-remove-rust.248198/

https://bmxmuseum.com/forums/viewtopic.php?id=351132

With muriatic/hydrochloric acid, with enough time you will end up dissolving a portion of the part as well as the rust.

 

Good to know. Thanks for sharing. With any aggressive chemical cleaning process, you need to periodically check it and remove it as soon as the reaction process starts to fizzle out. You can only clean something to a point without the process biting in and doing damage.

I've found the Acid Magic product is not as aggressive (e.g. no immediate burns if you accidentally get some on your skin) as compared to plain old Muriatic acid. But it is a little slower than the industrial Muriatic strength acid that comes in the quart bottle at the hardware store.

It one of those things that I discovered as a way to speed up a time-consuming process. I paint the cleaned parts with VHT header pain and bake them according to directions. It's good to see parts that you cleaned and painted 5 years later that still look good.

 

Evaporust works great and is a lot less "dangerous"

 

Thanks for sharing. I like seeing some alternatives to tackle different problems. I stumbled into this video about different rust removal products. Check it out.

I have a tendency to go for "Fast and Furious" cleaning products. Being able to "dip it and forget" for a few hours while it cleans keeps you from having to constantly monitor results. I didn't expect to see Krud Kutter perform so well.

https://www.youtube.com/watch?v=6-MC_ZEXQbw

 

Project Farm is every mans hero!

 

Yes indeed and cool. I'm ready to graduate from Chris Fix.

 

Looks like i'm ordering some krud cutter and muriatic acid (If you get a car frame/body "dipped" I'm pretty sure that's what they hot tank it in)

 

Be careful with it and don't damage you or your part. With extreme power comes extreme responsibility.

 

Can I use this acid to free rusted bolts on my bumper? I have some on the farm I can use.

 

I would use some penetrating oil. Muriatic acid or any kind of acid will rust again almost while you watch when exposed to air. It's great for dipping when I can recoat it with an oil to pickle it before rust returns.

 

I used this stuff on some metal garage door fittings and it worked well. Non toxic, non acidic, eassy clean up and lasts a long time.

https://www.homedepot.com/p/Blaster-1-Gal-Metal-Rescue-Rust-Remover-Bath-128-MR/312780997

 

has anybody heard of or used This product from MasterCoat?
is it close to this muriatic acid or something totally different?

Mastercoat Metal Prep & Rust Remover - Dissolve Rust FAST! (nomorerust.com)

 

I've used Blaster Rust Remover Bath with good results. It's non toxic and reuseable until it turns black. It's from the same company that makes PB Blaster. Good for soaking rusty parts. It also removes paint if there is rust under it that hasn't poked through yet.

Evap O Rust is similar.

Muriatic acid is also the active ingrediant in "Naval Jelly."