Removing Corrosion from Magnesium Plates

I’m not sure you can save any of the plates that have been corrupted.

This is what the engravers SHOULD do to help preserve the plates:

Recommended (to the industry) in Letterpress Platemaking, Wallis and Cannon, 1969. “As a protection against corrosion, magnesium engravings should be dipped in a solution of chromic acid, plaster of Paris, and water. The treatment causes a mild etching action and therefore the plate must be free of all oils (flush with alcohol) before immersing, which is only for 5-30 sec. After immersion, the plate should have a uniform brassy appearance.”

Or, put petroleum jelly on the surface areas to prevent oxidation.

Or, use copper or zinc engravings instead. They are far better a printing surface than magnesium but, of course, not as inexpensive. Then again, you get what you pay for.

Gerald
http://BielerPress.blogspot.com

try using a pink rubber eraser. Just “erase” the corrosion, then clean your cut as you normally would. Use the same method for lead type.

try using a pink rubber eraser. Just “erase” the corrosion, then clean your cut as you normally would. Use the same method for lead type.

Pink eraser! That’s awesome!
I have used a large block of charcoal. Charcoal is a very fine abrasive and if you rub the flat side of the charcoal block on the surface of the cut, the oxidation wears away. Be careful to rub evenly, so you dont round off fine serifs or make the cut uneven.

i found once the corrosion has “eaten” into the actual printing surface there is nothing you can do to save it. to prevent this from happening your die needs to be stored away from all air or moisture.
i bought myself a foodsaver on ebay and now once a job is done i spray the die lightly with wd40 and vacuum seal them until i need them again.