Technical Rust remover

Most rust removers, at the ones I've used, are phosphoric acid based. I had good luck with KrudKutters rust remover and bought it in gallon jugs to save on price over just buying it in the spray bottles. Now it seems they don't offer it in gallon jugs. My son is a dairy farmer and he used all kinds of chemicals to clean his milking equipment. One is milk stone remover and acid rinse. It's mostly phosphoric acid, more acid than most other rust removers so it has a little more bite than the weaker rust removers. I bought it at the local farm supply store for $20 a gallon, less than half the price at other places.

I soaked two really rusty parts of the sidemount brackets for my '37 Buick and the parts came out rust free. I had to soak them for about two days, rinsed them water and ran a cup brush on m angle grinder to finish cleaning them off but they came out really clean.

 

Interesting. I had a jug of evaporust that I was doing small parts with using a plastic container from the Dollar Tree. Put the part in the plastic pan, pour the rust remover in, let it sit, pull the part out and do the cleanup and Then using a funnel with a filter pour it into a clean jug to store until the next time.

 

I've been using a gallon of Krudkutter rust buster doing the same thing for a long time but eventually lost a little everytime I used it. It was time to buy more but couldn't find in the gallon jug anymore.

 

I have had great luck with plain old citric acid. It does wear out after a while after much use. Do not forget to neutralize the acid after the dip is done.

Edit: Make sure whatever container you use to store it, keep the factory label pasted to it. Think of the movie Scarface...

 

Plain white vinegar works great (in minutes/hours not days), is really cheap, you can get it at the grocery store, and is environmentally friendly.

 

I've tried vinegar, didn't do much on the rusty parts. Some in other posts mention muriatic acid, I wouldn't allow that stuff in my shop. Used it once to clean some copper bars and the next day any bare piece of steel within ten feet of my work are had a layer of rust on it. It's also pretty strong. I like phosphoric acid because it's somewhat mile and leave a phosphate coating that holds of rust for a long time.

 

I agree with Hellfish, I have had good results with white vinegar. I use it mainly for small parts.

 

I leary about using any type of acid for derusting. You really have to keep an eye on it so it doesn't get away from you. I like Evaporust (though it is expensive). It works by a process called Chellation which is not injurious to the base metal. For large jobs, I like Rust-911, which works like Evaporust, but not quite as well, but is a bit cheaper because it is a concentrate.

 

Blasting cabinet?

 

Blasting cabinet would be another way to go but I used a 8"x12" plastic container on my bench. I hate blasting. Like most I don't have a blast cabinet. When I do blast something I don't outside and it's a pain. I hate blasting, this is a lot easier, at least for me. Plus the phosphoric acid leaves a phosphate coating that holds off rust.

 

The trouble is anything that works well is deemed not environmentally friendly by the do gooders,and removed from the shelves. I use a “pacer” brand acid wash , it also keeps bare metal good for a long time , even in our coastal environment.

 

if you want something more eco-friendly, I remember a thread or threads here on the HAMB regarding the use of molasses for rust removal. I did a search on 'molasses' in thread titles and come up with quite a few.

 

From what I've read you need to find sulfur molasses, you need to go to a feed store. It also smells pretty bad.

There are many options, I'm just presenting one I have found to work really well and is relatively cheap and easy to use.

 

Double check your paint products when using Phosphoric acid, many epoxy primers have warnings against its use.

Interesting video here, make sure to read the comments some good stuff in there.

 

For those of you who do not want to spend 20 minutes watching the video, what he comes up with is something that doesn't work even close to well-used Evaporust (it's almost black, fer cripes sake).

 

I didn't mean to be a bit wipe. But for the cost of chemicals and the hassle with trying chemicals it seems the price of a cabinet and abrasives would pay for itself if you had a lot of parts to clean up. Lippy

 

Excuse the mess around it. Heating oil tank was free. My father had a couple laying in scrap pile. Gloves and gun I had. A few bucks for angle iron, plexiglass, weatherstripping, pipe, casters, expanded metal for grate, 2 halogen lights, and sheet metal for sump. Works great and roomy!

 

Black strap molasses works good, 1 gallon to 5 gallons water.

If you just need something small to clean small parts then a 5 gallon bucket with black strap molasses and water and your in business.

Places like tractor supply, etc carry black strap in liquid form sold by the gallon.

Molasses isn't harmful to metal and won't eat it like acids will. I've talked to farmers etc that said they've left parts soaking for months with no effect whatsoever to the metal.

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This is incorrect. Molasses is an acid, and will eat into the base metal, particularly cast iron. One of the older threads on here had a post showing this, including pictures. The pictures made quite an impression on me and I remember them well, but thanks to our friends at "PhotoBucket" they're long gone (the text is still there). Molasses has it's place and works well in most cases; just be careful checking it's progress. especially with cast iron.

 

white vinegar works great on nuts , bolts , small brackets...etc..just take a week...i could buy a gallon a couple of years back at the dollar store,,,no more at that price...

 

1952 henry, I do like the size of that blast cabinet that you assembled. Neat O.

 

There's no acid in molasses that's gonna eat metal. They feed it to horses for cryin' out loud! I just finished dunking my buddies two rusty '51 Chevy doors in a tank of it and they came out spotless. Several years ago I dunked my entire roadster body and it removed 90 years of rust. Didn't bother any paint or rubber. Here's my old post..........
https://www.jalopyjournal.com/forum/threads/rust-removal-the-miracle-of-molasses.557996/

 

Everything is acid, base or neutral (rare)....so what is this?

 

Phosphoric acid in soda water. Along with other chemicals.

 

I have used oxalic acid. It's slow. Maybe someone can educate me on the cons of it.

 

I've stated it here before: any acid will work to remove rust. Stronger acids will do it faster. It's the basic chemical reaction, because acid has H+ ions in solution. Rust is Iron oxide, and the H+ ions react with the oxide, forming H2O and making the acid weaker. The Iron ions (Fe3+) go into the acid/water solution. That's why older used acid gets weaker, the available H+ ions are less in number.

 

Krud Kutter to spray on, EvapoRust, to soak in.

 

I'm working on a V8 60, and before I did anything with the block, I wanted to try the electrolysis process. I dismantled the water pumps and mixed up the washing soda solution and immersed them for less than an hour. I need a better DC supply, but I'm happy with the result.


The engine was rebuilt 40 years ago and never run, but shed stored as a short block. I believe it has been set up for a boat, so the water jacket was a mess. I made some rubber head gaskets and filled it with Evaporust. There was some improvement, but since the flash rust in the valley and crankcase was so extensive, I thought I should immerse it completely. That led to the electrolysis experiment. The photos make it look better than it is.

 

I put two model T doors in a 10 to 1 molasses water mix in summer down under , for a month, one came out mint ,well they were both rust free. But one was very religious, holey, but rust free.