Rust removal

From
Transformation: Rust removal
ReusabilityNon-Reversible
Materials: Vinegars, Salts, Steels
Parts: Bins

Introduction

Rust remover is usually applied to objects that are difficult to sand blast, machine, or otherwise clean abrasively or mechanically.

Challenges

I tried Evaporust and did not like it. It seemed to leave a dark color to the treated steel which was not desireble. Don't know if I was using it wrong, but I was specifically testing several methods, and eliminated Evaporust because of this.

Approaches

Get some white vinegar from the supermarket and some water softener salt (pure salt, in the yellow bag; koshering salt is fine, too, but more expensive). Find a plastic container to hold all yer rusty stuff. Fill it with the vinegar, and add enough salt so that it won't all dissolve after two days. I use softener salt, and I like a layer of "beads" left on the bottom. OK, now you are ready to drop your degreased parts in.

This is critical: they must be COMPLETELY submerged. If not, they will corrode at the air-liquid interface. And fast.

Make sure there are no aluminum parts (like ID plates) mixed in, or they will, um, disappear. (Don't ask.)

Now, keeping them completely submerged, ignore them for 3 days. It's OK to kick the bucket (!) every time you walk by, but make sure everything stays submerged.

After 3 days, take the parts out and rinse in hot, clear water. Do not be alarmed by the rust all rinsing off. Dry off, and IMMEDIATELY spray with WD-40. (WD stands for water displacement... really.)

After you clean up (save the salt/vinegar solution... it's still good), wipe off the WD-40, and spray with LPS-3, or the rust preventative of your choice. Do not expect WD-40 to do the job.

I have tested this method with parts that were machined clean and measured carefully. There was no measurable impact on clean steel after 3 days. Rust, however, is removed with the wipe of a thumb at the end of the process.

References