My Dad and I recently tried using muriatic acid (also known as hydrochloric acid) as a cheap and very effective rust remover. I thought i would share the results for those people that may not know about it.
We thought we would try it on the under the bed crossmembers for my '56. the pieces were covered in surface rust and pitting.
I found muriatic acid at my local Sears hardware store ($4.99 a gallon). The jug said it was 31% concentration. I also picked up a 10 foot vinyl house gutter at Home depot.
We mixed it 8 : 1 Eight quarts water to 1 quart acid.
trimmed the gutter to length and lined it with plastic so it wouldn't leak.
most pieces soaked at least 6-8 hours or more. Im sure if the concentration was greater, it would work faster, but we were concerned about fumes, toxicity , etc.

after pulling the piece out, we neutralized the acid in a 5 gallon bucket that had water and baking soda (used a whole small box of baking soda in the water ), and then rinsed off with water.

the results were very good. completely took off all the rust and brought it to clean bare metal. IT WILL NOT TAKE OFF ANY PAINT. a couple pieces had some leftover old paint in spots and it didnt take that off. It would be best to hit those places with a grinder first.

here is a link to some pictures:

http://public.fotki.com/heck91426/

 

Looks good. I never used it on larger items.

Don't laugh too hard, but toilet bowl cleaner is like 10% and will work also. Just drop old rusty parts (small ones) in a jar full of it and let them sit for a couple of days.

 

That's some good stuff, I used it on a few parts also. Ventilation is key with that stuff, very toxic. Make sure to use a plastic container or you will have serious issues. I like the results and your idea of a baking soda bath is a good one.

 

My older brother and I cleaned the inside of a motorcycle gas tank with muratic acid. We used it straight from the bottle. It removed everything. To the point that when we washed it out with water there were instant rust blooms. The tank was then coated with some hardening tank liner goo. It's still in one piece today, 20 years later.

 

I use it all the time - buy it at a swim pool supply house - $4.00 for a two gallon pack. I use it full strength and check my pieces every 20 minutes or so. Works like a charm.

I scrubbed my firewall and the top of my cab with it - full strength. Didn't remove any rust, but did do a great job of cleaning it.

The water jacket on the engine in my boat was clogged with rust from running in salt water - soaked the engine for a week in about a three to one mix. Rust all gone, and everything else clean as a whistle.

One thing, I work outside and there are no kids or pets around. I use plastic gloves, but it does not seem to burn you if you splash yourself. When your acid gets dirty you can dump it on your lawn - it is a fertilizer. Just don't put to much in one place, it will burn your grass just like to strong a fertilizer will.

 

I've tried it but I prefer electrolysis. Be sure you completely neutralize the acid on the metal afterward or it will rust again...

Vern

 

vinegar is also a good overnight cleaner,,,,,,,,

 

To each his own I guess. But I personally have not used acid since 1973.....

 

We use to use muratic quite a bit in my geology club/ department as an undergraduate. It works wonders when we were cleaning up certain types of mineral samples. I do recommend using gloves though, the stuff does get a bit "warm" on bare skin even when diluted. Also as mentioned already, use it where you have ventilation, that stuff will knock you flat fast.

Luckily the stuff is cheap and works well on just about any part you can dip it in or brush it on.

 

Sodium bisulfite (swimming pool Ph DOWN dry powder) is a far safer product to use than muriatic. Mix a cup to 5 gal of warm water. Do not use any acidic cleaner on machined parts or you'll surely destroy them. We use bisulfite pickle solution to remove flux and oxidation after soldering precious metal jewelry. Once in a while I have a tiny wire drill break below the surface while drilling a blind hole in a piece of jewelry, I just put the piece in some pickle solution for a couple hours and the drill remnant dissolves away.
When mixing acid, ALWAYS add the acid to the water, not the other way around! Wear rubber gloves and face shield at minimum, even a dilute acid solution can blind you in a matter of moments! Keep a container of baking soda solution at hand at all times to immediately neutralize any splashes on yourself. NEVER EVER combine muriatic acid with any product containing ammonia, the reaction of the two will produce a deadly gas. If you must use a mineral acid, I'd recommend using Sulfuric acid (battery acid) instead. Still very corrosive, but less likely to be deadly.
PS: I have never heard of HCl being a fertilizer!

 

acid! ah yes-you know what they say about the 60s..if you can remember it you wernt there.

 

muratic acid works well. but can cause instant rust blooms when removed form the acid. even walmart sells it 3.00 for a 2 pack. even most supermarkets sell the stuff.

 

Muriatic acid sometimes used to clean grout off tops of unglazed tile. Once had an installer use it on a kitchen tiled floor; the fumes really messed up the finishes on other metals in the kitchen, so if you do use it keep that in mind.

 

I've got gallons of this at home, but mom freaks about me using it for anything other than pool water.... electrolysis is the only method I've done. -4speed

 

That is why most of us don't live with our mothers - maybe our children's mothers - but they are more apt to let us do as we wish.