Chemistry Is Your Friend - Simple Rust Removal For Chrome
 

Hey all,
I've been restifying BMX bikes as of late, and decided to take some pics of the process I use to remove rust from old chrome bolts and other assorted chrome parts. The technique I use is very simple - make a bath of Citric Acid Powder and water, and soak the parts. The ratio is 8oz. of CAP for every gallon of water. It's environmentally friendly, non-toxic, and super easy to do! Here's some pics and a quick writeup. Enjoy!

Step one - gather your rusty parts, and the citric acid powder. You might need a lot of this stuff, depending on how much you need to clean. :) I got my citric acid powder at a store that sells wine and beer making supplies, along with canning and bottling equipment. So, if you have a store near you that sells supplies for home brewers and such, chances are they will have it in stock.

http://i256.photobucket.com/albums/h...psbaeaa30f.jpg

You can make the bath as large or small as you need, as long as you keep the ratio the same. This pan uses less than a gallon of water, so I used less than 8oz. of CAP.

http://i256.photobucket.com/albums/h...ps6b3f50fb.jpg

Closeup of rusty parts.

http://i256.photobucket.com/albums/h...ps74c60f12.jpg

Same parts, about 4 hours later. Note the bubbles around the parts - science is working!

http://i256.photobucket.com/albums/h...psdc39bde9.jpg

I removed this washer after about 7 hours in the bath. Note the clean side - I merely wiped the rust off with a shop rag.

http://i256.photobucket.com/albums/h...ps92f3cdc0.jpg

Here's how everything looked at the end. I just had to wipe the parts off with a Scotchbrite pad and rinse in cold water to remove the acid. Amazing!

http://i256.photobucket.com/albums/h...ps3f4df469.jpg

http://i256.photobucket.com/albums/h...psbf022ef2.jpg

Now, this will work on seriously rusty stuff too - you just have to let the parts soak longer. Here's a 1983 Murray frameset - some of the chrome was compromised already, as this bike sat in a damp garage for almost 30 years. Here's the before shots -

http://i256.photobucket.com/albums/h...psc8c762e4.jpg

http://i256.photobucket.com/albums/h...psce0c124f.jpg

http://i256.photobucket.com/albums/h...ps0d940c8d.jpg

And after 27 hours in the bath. Notice the decals did not get damaged or lift at all. Science is awesome!

http://i256.photobucket.com/albums/h...ps3e9ed0fd.jpg

Once the items are removed and rinsed, you may want to protect the chrome finish to help prevent it from re-rusting. I went over the frameset with Turtle Wax Chrome polish because I ride it everywhere.

Another good way to protect them is to wipe the parts down with a rag soaked with WD40. Some of the other things will not re-rust as long as they're out of the elements - those small bolts still look fine after several days, and I did nothing to protect them. I've also tried this experiment on bare metal (like a kickstand and a seat clamp) and it removed all the rust, but it showed some surface rust not long after. I wiped that off with 0000 steel wool and it didn't come back. Hope this info can help you guys!

Great write up. I got some tools this will work well on, thanks

Steve,

Looks great!

How are the parts protected from re-rusting quickly?

Definitely! One of the things I tossed in that little pan was a rusty Husky socket I found walking through a parking lot. It came out great.

Doh! I should have added that info, eh? ;) With the frameset, I went over it with Turtle Wax Chrome polish because I do ride it - I'm not a collector that lets the bikes sit on display somewhere.

Another good way to protect them is to wipe the parts down with a rag soaked with WD40. Some of the other things will not re-rust as long as they're out of the elements - those bolts still look fine, and I didn't put anything on them. I've also tried this experiment on bare metal (like a kickstand and seat clamp) and it removed all the rust, but like you said, it showed some surface rust not long after. I wiped it off with 0000 steel wool and it didn't come back. I'll edit my first post above to reflect this info I forgot. :) Thanx Bill!

Very cool stuff, I'll have to remember this. Where do you pick up CAP?

I got it at Corrado's market in Clifton - they sell wine and beer making supplies there, along with canning and bottling equipment. They use it for adjusting the pH levels in wine and beer, and cheese making. It's also used as a flavor enhancer for baking. So, if you have a store near you that sells supplies for home brewers and such, chances are they will have it.

I believe you can get similar results with simple white vinegar. Vinegar is acetic acid

True enough - I've read some restorers will use vinegar on bike frames. But, vinegar is stinky. :) This stuff is practically odor free, which is another bonus.

Similar but not quite as good. Takes longer and won't be as aggressive.

Kind of like the old wive's tale about using Coca-Cola. Yes, it has a small amount of phosphoric acid in it that will eat rust but nowhere near enough to do some heavier cleaning.

Not according to what I have seen. Its pretty aggressive. Someone over on NastyZ used it on some pretty heavily rusted rotors and they came out pretty nice. Vinegar has a fairly high acid content.

http://www.nastyz28.com/forum/showth...hlight=vinegar

Hmm. Maybe I just had old or weak white vinegar? I'll have to give it another shot.

Taco Bell fire sauce will clean stuff up too