View Full Version : Naval Jelly used on cast iron

Mark Beiser
09-21-2003, 12:18 AM
I ran into a stopping point on my brake system overhaul, that pesky parts aquisition thing, and decided to clean up my brake drums a bit.

The car lived in and around Pittsburgh, PA for 24 years, so there was QUITE a bit of rust on the drums.
After wire brushing most of the rust off by hand and with power tools, I used some naval jelly to get the remaining rust out of the pores of the cast iron.
After rinsing them off and letting them dry, I started brushing off the white powdery stuff that formed on the surface.
As I was brushing, I noticed that the surface of the cast iron had a dark gunmetal gray to it that looked quite nice. It wasn't uniform in darkness, so I did another treatment with the naval jelly for a few min. After rinsing, drying and brushing the metal again, the color came out very uniform.
It looks almost like the rough surfaces on cast iron cookware.
The machined surfaces didn't have as much of a color change, but they did grey a little.

I realize the color change is due to iron phosphate in the surface of the iron due to the chemical reaction with the acid in the naval jelly.
It is my understanding that the iron phosephate stabalizes the surface of the iron against oxidation. I could be way off on this though. Its been a long time since I studied chemistry, and never studied metalurgy.

The question is, how resistant to oxidation will it be?

I am painting the brake drums on this car, but if the use of naval jelly on cast iron parts has the effect of making them rust resistant, I'll be needing to find a supply of naval jelly in larger containers than what auto parts stores sell. images/icons/smile.gif

09-23-2003, 04:40 PM
Hey Mark, It's been along time since I've used the stuff but I belive it takes it down to absolute bare metal. I don't feel that would last long before rust returns. I got this off search
on Naval Jelly--Google

Known and trusted for decades, Naval Jelly dissolves and removes rust from heavily rusted items without sanding or scraping. Just brush it on, watch it dissolve the rust and rinse off. For long-lasting results follow up with a protective coating of rust preventer or prime and paint the surface.

Hope this helps

Dave Russell
09-30-2003, 08:38 PM
Well live & learn. I always thought that naval jelley was made from navel oranges.

10-26-2003, 03:12 PM
I'm no expert but I've done a few restorations and have been told by sager men than me that you should never use navel jelly on suspension or brake parts because it changes metal structure and weakens it.

11-02-2003, 02:32 AM
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Dave Russell:
Well live & learn. I always thought that naval jelley was made from navel oranges.

I thought it was belly button jam images/icons/tongue.gif

11-02-2003, 09:08 PM
DON'T EVER LET THAT STUFF THAT BUILDS UP BETWEEN YOUR TOES TOUCH METAL EITHER!!!!! graemlins/lol.gif graemlins/blush.gif graemlins/blush.gif graemlins/blush.gif graemlins/blush.gif graemlins/blush.gif graemlins/blush.gif graemlins/jester.gif

[ 11-02-2003: Message edited by: jv ]</p>