On Thu, 27 Jul 2017 12:54:52 -0700 (PDT), Sonny
wrote:

Doing a little maintenance around the shop, decided to change the jointer blades. 6 to 8 months ago, I had 2 sets of blades sharpened and rolled them in the blue shop towels, for storage.

I discovered all the blades have developed rust spots. I suppose the towel's acid caused the rusting. The towels were stuck to the blades at the points of rust. There was no signs of any discoloring/blemishing on the outside of the wrappings, so I doubt the cause was from an exterior contaminate, migrating inward.

Scroll right for 2 more pics.
https://www.flickr.com/photos/438361...posted-public/

I have older sets of blades wrapped in regular paper towels and in brown paper bags... no rusting on these.

I had planer blades sharpened at the same time as the jointer blades. Planer blades were stored in their designated cases. No rust on these, so whatever caused the rusting didn't come from the sharpener.

It may not be acid in the towels, rather that they're absorbing water
from the air. I had this problem with a pistol case. It had a canvas
spine that absorbed water and rusted the stainless steel along the top
of the barrel and back of the grips. Rust on a $1500 gun sorta ****ed
me off.