Thursday, August 14, 2008

Wax on, wax off.

This being a print shop, we've got a whole lot of metal to take care of. Most machines of letterpress vintage are largely cast iron. As there are some surfaces that cannot be painted (or at least kept that way,) this means fighting rust is a constant issue. Once a surface is cleaned of rust, which is a separate topic in itself, it needs to be protected from further rust. A coat of wax does a good job of this.

At first I tried this wax, as it is probably the most easily found at the hardware or grocery store. It works fine for most surfaces, but not so well for things that paper touches, such as cutter tables. This is because it has a waxy butterscotch sort of color to it, which can rub off visibly on white paper. This issue led me to the Butcher's wax. It is clear, possibly because it was originally intended for waxing maple bowling alley surfaces. It also smells nice, in a piney-turpentine way.

Though our shop is air conditioned, it's humid enough around here in the summer that the table of our Challenge cutter will get a powdery rust coating overnight. (The ideal solution would be a Polar cutter with a stainless steel work surface, but that's a way off.) Even after the rust is wiped off, the wax still inevitably gets some amount of rust mixed into it as it is applied. Eventually the wax builds up and starts to leave slight rusty marks on the back of the paper as it slides around the paper table. So far my solution has been to periodically strip the wax off as much as possible and start over, but it's pretty putzy. Still trying to find a better solution but it works for now.

Wax is also useful for the beds and platens of platen presses. These are machined cast iron and so are prone to quick rusting. It seems that the tympan and packing on the platen can trap a bit of moisture against the platen, so when it is changed and the platen exposed, it's an opportune time to wax it for good measure. On the Heidelberg windmill, this is one of the few spots prone to rust, as pretty much everything else is painted black or nickel-plated.

Oil is another good rust preventative - luckily for us, almost everything that isn't constantly wiped down will have a film of oil on it. These machines predate things like sealed bearings or delrin bushings. They like to have plenty of oil. Our task is to keep them well oiled, while keeping the parts that touch paper - expensive, bright white paper - perfectly clean. Which will be a topic for another time...

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