Be very careful using Muriatic acid. Muriatic acid is the generic name for Hydrochloric acid. Hydrogen embrittlement is a major problem during Hydrochloric acid pickling of mild steel. This embrittlement occurs when atomic hydrogen produced by the introduction of the acid diffuses into the lattices of the metal and strains it. This results in brittleness at the molecular level with no advanced indications such as visible pitting. I wouldn't suggest using it on anything more than a couple of minutes, and never on springs or structural elements. Also steel pickled with Hydrochloric acid tends to re-rust fairly quickly and needs to be treated with phosphoric acid afterwards to prevent this.

I use 3 types of acid to de-rust parts:

Citric Acid, which is a weak acid that is a little stronger than the acetic acid found in vinegar. It is used commercially to clean stainless steel and if left a while it will remove rust. I use this acid on critical structural parts bolts and springs, it will just take longer than the other acids. I get it in powder form and mix the concentrations as needed.

Phosphoric Acid, which is the weakest of the strong acids. I use this acid for most other parts because its relatively quick acting.

Hydrochloric (Muriatic) Acid, I only use Hydrochloric acid in very special instances (like if I'm being very impatient and I want instant results).

Happy de-rusting

Jughead, for the parts that you showed my prefered method would be to nylox brush them then a little phosphoric acid followed by a Rub 'n Buff/Calyx mixture to make them look like new.

 

Anyone ever try Rust Bullet? I'm thinking of using it on my frame.

It's suppose to coat over rusty metal, and be better then POR15.

http://www.rustbullet.com/

 

I sprayed my frame with it and top coated it with satin black... seems good. Def. looks good on the suspension parts I left natural

 

So I left the pieces in a little longer than I originally planned. This was after about 36 hours. All the rust is gone and you can see on the pipe how pitted it is. Both pieces look much better and don't feel like the syrface has been "etched".

On the tubeing you can see where part of the tub wasn't under the solution...it's still rusty. I did that purposefully for comparison.


After 12 hours:




After 36hours:

 

Hm...Len what kind of brush did you use after you took them out? andh ow does the metal feel after rust is removed?

P.S. I have some rust under my distrub cover if I apply that stuff you think it might remove the chrome too or just rust?

 

Didn't use any brush, just ran under water to clear. Surface isn't 100% smooth, but isn't rough or raised like after a vinegar bath.

Don't know how it'd work on chrome. Maybe checkout the website to see if they have any pics of chrome work.

 

Hm...This product + that rub n' buff stuff is giving me ideas

 

Sorry for the double post, but I was reading thier website and I found this:

O P E R A T I N G T E M P E R A T U R E:
Ideal operating product temperature range is 70 degrees F to 120 degrees F for performance efficiency. This means if you can de-rust an object at 70 degrees in one hour, it could take up to five hours to do the same object at 45 degrees temperature range possibly.




Maybe if you apply it in an oven it will work alot fast with better results

 

Just a thought but why not use a Croke Pot and put the stuff in there that way you can set the temp and leave it. . I fly RC Airplanes and have used this method with anti freeze for cleaning really gunked up model airplane motors.

 

Muriatic acid is just weak hydrochloric acid and I have used hydrocloric acid alot for removing rust and it only takes a few minutes.
I would go with the muriatic. That stuff doesn't work fast enough or do a good job.

 

Guess I'm gonna have to try some muriatic acid. Wish you guys woulda said something earlier.

Where in HomeDepot might I find some muriatic acid?

Is that the same stuff used to "etch" concrete floor before painting?

Kept in the paint dept?

(Thanks Gator)

 

Yep

 

But acid products will damage chrome, and paint

 

Pool supply section. It's what I use in the pool to adjust the PH.

Be very careful with this stuff. Use rubber gloves and goggles and don't breath the fumes. Also use plastic or glass containers it will eat through a metal can.

 

That stuff is pretty good.

 

Nothing beats Coca-Cola for getting rust off parts

 

Never tried coke. Wouldn't it peeter out after a few hours?

 

I've used Coke/Pepsi any cola really for getting battery corrosion off the battery posts, but never tried it for rust.