Rust removal with muriatic acid

[Stan in Oly, WA]

I made some handles, door stops, hinges, and other miscellaneous hardware out of mild steel for the doors of a shed last year, but a different problem prevented me from being able to install them. Sitting in my unheated garage they got rusty over the winter. Doing a different project I noticed that muriatic acid was an effective rust remover, although it made the metal immediately susceptible to surface rust afterwards. If I use muriatic acid to clean the rust off the metal, and then immediately neutralize it with an alkaline rinse, after drying will the surface be ready for primer and paint at that point or do I have to do more?

Stan

 

[Geo-TH,In]

Acid will remove rust. So will chlorine bleach. Rinse it off and you'll and watch the rust appear.

However I would buy a rust converter that turns metal black, converting Iron oxide back to Iron.

So you can do the acid first, followed up with a rust converter.

 

[Steve A W]

Here's a product that this youtuber likes.
I've not tried it but have seen him use it.
Road King

 

[BobReeves]

Looks to be basically the same stuff as EvapoRust, I use the 20% off coupons and get it at harbor Freight. Not sure if this stuff is cheaper or not.

 

[showcrop]

muriatic is faster but it leaves you with a problem. That is why everyone recommends the phosphoric acid rust converters. Read about them under paint and body work. You can read about it there for days.

 

[tomturkey]

Must for Rust is a brand name of phosphoic acid that converts the rust and preps for painting. It tends to leave a white residue but just scuff it off with a scotch pad and then prime and paint. gobble

 

[urbancase]

showcrop is right, I do engine blocks for rebuilds on my tractors and I strip the blocks and dip for 24 hours in phosphoric acid. it is the better way for metal.

 

[Bruce(OR)]

Baking soda neutralizes muriatic acid. I still have a 5 gallon bucket of it out there somewhere. You could use the acid to eliminate a good deal of rust, then the soda rinse followed by phopho rust converter. That should get you as close as you might get with minimal physical labor into paint prep.

 

[Jeff in ND]

Milking machine cleaner. Mix of Phosphoric acid and some soap. Cleans rust and grease at the same time! I've used "Stone-Solv" from Fleet Farm. Keep a eye on what you are dipping it will eventually dissolve the metal after the rust is gone. Best to dilute it if the rust is not heavy.

 

[Stan in Oly, WA]

Jeff in ND; Does this look like what you're talking about, or close enough?

Thanks, Stan
Possible alternative locally available

 

[Jeff in ND]

I bet it is the same stuff with different brand name:

https://www.fleetfarm.com/detail/milkhouse-brand-milkstone-remover-acid-rinse/0000000094523?bc=11798|11799|11815|11816&brandCrumb=3588819739&bn=milkhouse-brand

Note the logo on the bottom of the jug in the two !

For some larger item, mix with water in a tub. I've used it straight in a pickle jar on bolts, etc that I can't find a replacement for and need to clean up the old one.

Wear rubber gloves and goggles and don't get any acid on a cut/sore on your hand or it will take FOREVER to heal up.

 

[showcrop]

(quoted from post at 10:23:48 08/28/18) Jeff in ND; Does this look like what you're talking about, or close enough?

Thanks, Stan
Possible alternative locally available

Stan, The "other information" for the product tells you that it is phosphoric acid based, so it is what you want. The chemical manufacturer that I work for makes an equivalent product that I have used for rust conversion.

 

[Stan in Oly, WA]

Thanks.

 

[Stan in Oly, WA]

Jeff in ND; Thanks. I'll try that.

Stan