chemical rust removal question

[Travis Williamson]

Im new to all this restoration stuff, so bare with me if this has been asked before.

Does anyone know of a inexpensive chemical to remove rust?

I would like to remove the rust from my coil springs and a few other odd shaped parts. Rather than wire brush them or blast them, I was kind of wanting to soak them in a 5 gallon bucket, which is why I need inex*****ve. This would save me a lot of time as I can be doing other stuff while soaking the parts.

Thanks
Travis

[Bryan L.]

Re: chemical rust removal question

either muriatic which is swimming pool acid or phosphoric acid which is in a product called Os-Pho will do the trick. The muriatic acid will be much cheaper, usually just a few dollars a gallon.

BL

[Michael H.]

Re: chemical rust removal question

Using any type of acid on springs it definitely not recommended. A process called hydrogen embrittlement occurs that will destroy the spring. If you've ever tried to clean an old spring ring hose clamp in anything, even as light as naval jelly, you quickly learn that it becomes brittle and will snap instead of expand when you try to reinstall. At the least, it would weaken the spring. Anyone that lives in an area of the country that uses road salt can varify the results of this chemical on coil and leaf springs.

It is possible to reverss the effects of this hydrogen embrittlement process but I only know it involves heating the spring to some certain temp.

[John O.]

Re: chemical rust removal question

Hi Travis

Sand blasting is a great way to remove the rust.I did it on my springs. But if you want a chemical to use, I saw in the Eastwood catalog this stuff that dissolves rust. It's call Eastwoods rust dissolver and it's acid free.They also sell a product called Rust Encapsulator. It neutralizes and primes in one step. If you don't have there catalog, go on line at www.eastwood.com to check it out.Their phone number is 1-800-345-1178

Good luck...John

[Mike McKown]

I've done a lot of rust removing with muratic acid

I've experienced what Michael says is true on brake springs for example. I've also found that if you're just removing light surface rust with all the grease removed, a bath in 30% muratic acid cut 10-1 with water for a couple hours will do wonders in removing rust wiothout any apparent ill effects. If you do decide to proceed at your own risk, have a similar size vat of water with a baking soda solution mixed to kill the acid. If it bubbles a little when you bring the part out of the acid and into the soda water, you're about right. Rinse well with water. Clean with Castrol Super Clean and a scotch-brite pad and you'll probably like the results.

Another caution: use the acid outdoors or at least cover if it is indoors. The fumes coming off the acid will spread through your garage and corrode anything it touches.

I deny any liability for the above. I'm not qualified to dispense this information and charge a fee. Proceed at your own risk but I do it.

[Gerard F.]

Try Jasco Metal Etch

It is mainly phosphoric acid, gentler then muriatic. Dilute per instructions on the container. You can also heat it up and it works better. I use it for plating prep.

Jerry Fuccillo
#42179

[Michael H.]

The "Acid Test"

Here's a test that may show just how seriously any form of acid affects steel, especially spring steel. Dig out an old spring ring hose clamp. (one that you don't need) Test by completely opening and closing the clamp several times with the proper tool. Now, clean it for about five minutes with an product that contains any of several different types of mild acid, including those mentioned above. IMPORTANT next step. Wear complete face protection and again try to open the clamp. In a few weeks you will probably find both pieces somewhere in your garage. Hydrogen imbrittlement come quickly and as far as I know, the only way to reverse the process is with some form of heat but I have no details or specifics. Must be some info on this somewhere on the internet.

[Michael H.]

Hydrogen Embrittlement Advisory

More important info on the effects of hydrogen embrittlement. The link below will partially explain what it is and what it does to metal. For safety reasons, it's critically important that no form of acid, even the so called "mild cleaners", ever be used on steering, brakes or suspension components, including nuts and bolts. It drastically affects the integrity of the component. Good reading for all.

http://www.corrosion-doctors.org/Forms/embrittlement.htm

t

[Daniel C.]

Re: chemical rust removal question

Check out this site www.ridrust.com I am using this stuff and its Great.

http://www.ridrust.com/

[Jean C.]

Re: Hydrogen Embrittlement Advisory

Thanks for the info Michael. As noted in the article, some forms of electroplating result in hydrogen embrittlement...a cause for concern in re: chromed suspension parts on street rods!

Best regards,
Charlie

[Travis Williamson]

Re: Hydrogen Embrittlement Advisory

Thanks everyone for your responses.

Im glad I asked, I didnt realize that soaking metal in acids had a hydrogen embrittlement side effect.

After all this discussion, Ill be safe about it and spend the extra time just have the parts blasted!

thanks

[Mike McKown]

I tapped onto this link this morning after you

posted.

Unfortunately for me, I have neither the technical background nor the technical vocabulary to decipher what it said.

Things I did pick out, acid doesn't like aluminum or stainless steel. It doesn't like spring steel. Welding, corrosion (what you're trying to remove) and others also leave this effect.

It also said, given time. the hydrogen escapes from the metal and the metal returns to it's natural state.

So what's up with this???????????????

I can tell you now, I should/could be in deep doo-doo after reading this link because I have two cars that have had most of the running gear(s) cleaned in muratic acid including the coil and leaf springs. Several years later however, everything seems to be okay.

I would agree that if you soak a coil spring under tension in acid, it will break. I've had it happen. Could you conceive the idea that if spring steel is not under tension, the hydrogen will escape and the metal would be okay?

I'm a little confused by this link and wish somebody with the proper chemistry background could respond. I'm just a DA hillbilly.

[Michael H.]

Re: I tapped onto this link this morning after you

Mike,

I agree, some of the info on that page didn't exactly pertain to our cars or the things we do to them. Basically, the higher the quality of the material, the more it's affected by this hydogen embrittlement thing. Seems like muffler hangers and bumper brackets are on the other end of the list and don't have near as much trouble with it.

It's true that, in time, most of the effects of hydrogen embrittlement cease and the basic physical makeup of the metal returns to near normal.
The bad part of it is, if hydrogen embrittlement occurs, most often small cracke develop in the material which will never heal. The cracking problem becomes much worse if the part is reinstalled and stressed, even lightly, before cured, especially in the case of springs or other parts that flex.

The link that I posted was probably a bad choice but it was one of the first I found on yahoo. I have (somewhere) a four or five page paper on this and when I find it, I'll send it to you. Pretty interesting stuff.

The aircraft industry has a lot of info on it also as much of the nose wheel gear on most of the commercial airliners is titanium. That's another one of the reasons they don't use salt on runways. (supposedly)

[John H.]

Re: I tapped onto this link this morning after you

OEM parts that are zinc-plated these days, like fasteners, are oven-annealed after plating to drive off the hydrogen that occurs as a result of the plating process. I remember an episode during a new-car launch in 1991 when the flanged heads of self-tapping gas/brake line clip screws started popping off about an hour after they were installed and began ricocheting off the floor all down the trim and final line and in final process; every time one let go it sounded like a small-bore rifle shot. Turned out that the fastener supplier had an internal process screwup on that lot of fasteners and they didn't get annealed - went from plating directly to packaging instead, and the internal stresses set up by torquing them caused the micro-cracks (from hydrogen embrittlement) to become complete fractures, turning the bolt heads into bullets when they broke. Had to change every one of them (about 20 per car) on about 400 cars. Just one more of the "delights" of a new-car launch.