Platen Flattening

Things have been slow on the press restoration front. After some unexpected wrist surgery last fall, wearing a cast, PT, and readjustment took their own sweet time. Also, winter made working in an unheated space difficult, so the schedule slipped even further. After that, and some other distractions* (see below), I’m more or less back now, and the project is beginning to pick up again. I’d like to move it into my shop by early spring. The story so far:

I had found and engaged a recently retired sign painter to pinstripe the press, but this is as far as he got before he fell off a ladder and decided not to be a sign painter anymore. (I have another sign painter lined up for when we return to the pin-striping stage.)

During my downtime, I thought a lot about how the old, abused platen had always bothered me (due to the extensive surface pitting from rust during the pallet years). Platens rarely survive in pristine shape for 100 years; over time, the cast iron can warp, or low spots can be beaten into them with repeated over-impression. An uneven or damaged platen can necessitate extensive makeready and uneven impressions. This one even had teeth marks from steel perforation rule. 

After much dithering, I decided to machine the surface smooth. I will skip the entire “let’s import another NewStyle Gordon platen from the East Coast to see if it fits” project because, in the end, it didn’t. Well, it did fit on the pivot, but some other machine screw holes didn’t align, so it got set aside as a “use only as a last resort” spare.

So, plan C – flatten the platen:

This is my friend Don’s surface grinder. He bought it for $100 and rebuilt it (as he always does with tools). Don and his brother Steve instructed me on its care and feeding and necessarily assisted in the setup of this project.

Note the robust exhaust system to carry away carbide & metal dust (a necessary part of any grinding operation). The platen is mounted with D-tape to two pieces of (recently surfaced) steel furniture, which are held in place by a magnetic base secured to the bed. The wheel on the right raises and lowers the cutting head in increments of 0.001″, but you can adjust to 0.0005″ if you read between the Vernier lines. The middle wheel moves the table in and out to similar levels of accuracy – for a clean surface grind, each pass of the cutting head should move horizontally by less than 1/16″. The wheel on the left moves the ball-bearing table back and forth, ensuring lots of frenetic wheel turning. The grinding took four complete passes, each removing 0.001″ of material for an estimated total of 0.004″ removed. For purposes of comparison, typing paper is 0.003″ thick (to find out how I know this, you will have to read to the very end of this post). Some low spots were eliminated, and most of the rust pits were removed or minimized. Most of it is now effectively better than new.

Measuring the few remaining divots and rust pits – as one does. The surface is really flat, and the flaws are at the edges where nothing is ever printed. Now, I just need to cover it with a protective coat of paste wax and return it to the press. 

*PS: My Christmas present last year was an antique Hacker Plate Gauge.

We found it in an antique shop in Colorado Springs on the Saturday after Thanksgiving (and it qualifies as “antique” because it’s 100+ years old). I removed the somewhat abused dial indicator and took it to a business that specializes in repairing test equipment (BHD Test & Measurement in Broomfield, CO), left it to their tender mercies, and started restoring the wooden case. The dust was caked on, so I used a carbide scraper to clean it off. I polished the brass hinges and handles, repaired and glued some warped veneer, and lightly sanded & refinished the oak case.

The indicator was returned with a clean face, a new crystal, and a calibration report. After 100 years, it was only off by an average of 0.0006” – well within the tolerances of my letterpress measuring requirements (it couldn’t be brought into closer tolerance because the company that made it in 1919 doesn’t exist anymore). I’m now working with a paper conservator in an attempt to have the instruction sheet deacidified and cleaned up. How successful we will be remains to be seen, but I have enough photographs of it to reset the type (digitally) and produce a replica to reinstall in case.

By the way, this tool’s original use was to accurately measure the height of printing plates, type, and paper thickness.