Anyone who works with old car parts has experienced the need to remove rust from an iron or steel part. Abrasive blasting is one way to remove rust, but what if you don't happen to have a bead blaster, or if you don't want to change the surface texture of the part you're working with? A new class of liquid products provides an alternative using a chemical process known as chelation.
One such product is Evapo-Rust. I recently found it for sale at my local Harbor Freight store, though it can also be bought online and at other retail stores. I've had some luck using it with lightly rusted parts, so I thought I'd try it with a heavily rusted Kelsey-Hayes cast iron combination brake valve to see what it could do. Here's what the brake valve looked like before treatment:
Looks nasty, right? I put the valve in an extra large plastic drink cup and then added Evapo-Rust until the valve was completely submerged. After letting it soak for 24 hours I removed the valve and rinsed if off with warm water. Here's what it looks like after treatment:
Much nicer! I blocked off all of the ports because I didn't want the fluid to get inside the valve. It won't affect the internal rubber and brass parts, but if anything is rusty inside I'd rather clean that out manually. I'm pretty happy with the results!