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.
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.
Closeup of rusty parts.
Same parts, about 4 hours later. Note the bubbles around the parts - science is working!
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.
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!
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 -
And after 27 hours in the bath. Notice the decals did not get damaged or lift at all. Science is awesome!
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!
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. 
