Look around: you won't find much information on the Web to tell you about how to use Naval Jelly to remove rust from motorcycle parts (as well as garden tools, lawnmowers—whatever). At least, that's what I discovered. Yet it is often recommended. I wanted to know:

• Is it safe to use Naval Jelly indoors?
• What should I do with water used to flush parts I've treated? Will its residue kill my pets (and if so, how quickly?) or damage my lawn? Is it safe to let rinse water into the sewer system?
• How should I treat or dispose of steel wool, brushes, and other tools used when cleaning a part with Naval Jelly?

Frustrated by my inability to find answers, I contacted Permatex, Inc—which sells a brand of the pink acidic gel—and was directed to the company's technical services department. I ended up speaking with a friendly and helpful chap in Solon, Ohio. Here's what I learned:

1. Yes, it is safe to use Naval Jelly indoors. I'd want a bit of ventilation to ensure I don't inhale its fumes directly, but I don't have to worry about causing an explosion when my furnace lights up. However, using it indoors creates a problem when it comes to flushing parts with water. The laundry tub is perhaps not the ideal solution for larger parts. Everything considered, I decided I should work outdoors whenever possible.
2. Naval Jelly washed off parts (and the crap it has removed) won't damage my lawn or kill my pets (my spouse and cats are rejoicing). Water pretty much neutralises Naval Jelly. According to a Material Safety Data Sheet (MSDS) that I downloaded from the Permatex website, Naval Jelly is mainly water to start with—roughly 50-60% water, in fact (it can be more than that depending on the manufacturer). Another 30-40% is phosphoric acid—the stuff that does the work on rust. Phosphoric acid is the relatively corrosive complex acid of the primary organic element phosphorus, which is extremely poisonous by itself. Yet phosphorus is also essential to all kinds of life. That's why phosphoric acid is used in fertilizers. Incidentally, it's also a flavouring agent in foods and a primary ingredient of carbonated soft drinks. Other ingredients found in Naval Jelly, such as sulphuric acid, are in small amounts—typically less than 1%—so when diluted with even more water the used Naval Jelly should be safe. I should just be careful while using Naval Jelly not to ingest or inhale any, or get it in my eyes or on exposed skin.
3. I should wear rubber gloves and eye protection when working with the stuff. Simply brush it on parts and let it sit for a while. I was told that afterwards I should rinse or wash steel wool, brushes, and other tools used to clean parts. I should continue to wear protective clothing until the work is completed, and then wash my hands in particular with soap and water.

That's it. Other fundamental information is covered by the manufacturer's instructions and MSDS. I'll read both again carefully before attacking any parts with Naval Jelly.

Visit www.permatex.com or contact the company's Technical Services at 1.866.564.8461 if you want additional information.

Other sources:
http://scifun.chem.wisc.edu/chemweek/H3PO4/H3PO4.html
http://pearl1.lanl.gov/periodic/elements/15.html

Of course, another rust removal option is to use electrolysis. I've read several good articles that offer safety instructions and complete do-it-yourself plans for electrolytic cleaning. Try:

http://www.rowand.net/shop/tech/electrolysis.htm
http://www.oldengine.org/members/billd/electrol.htm