1442 CARD READER/PUNCH RESTORATION
I received the grit and did a test slurry. I discovered several things from the test. First, medium grit (1/4 millimeter) is way too coarse to match the original ceramic grit, but fine grit, about a tenth of a millimeter diameter, is a great match. Second, mixing the grit with the glue first produces unsatisfactory results.
My second try was much more successful. I used fine grit, put a thin layer of adhesive on the wheel and poured the grit atop it. I tamped it down slightly with my finger and then cured the adhesive with UV light. I have a couple of small sections that are too bare, but most of the wheel surface is already good. Later I will try to fill in the sections without raising the surface too much.
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repair in process - bottom wheel, left side original, right is repair |
I also have a high spot near the join with the original ceramic. I will carefully grind it down and if too much grit is lost, dig it even lower and add adhesive plus grit to relevel. I feel good about this process and should be able to finesse this into suitable condition.
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Wheel damage before I filled and began restoration |
Sunday morning saw the completion of the wheel. I smoothed and filled in the top surface, have enough grit to ensure a great grip on the punched card stock as it is moved through the punch station. I decided to add some grit to the sides of the wheel, since cosmetically the clear adhesive in the repaired section was noticeable. I didn't fuss with exact fit or appearance, so that the sides are a bit more patchy, but overall the wheel is ready for re-installation, once I flow off any remaining lost grit especially near bearings and turning surfaces.
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Wheel ready for final cleaning and then installation |
The part is cleaned and reassembly is starting as of Sunday night. I have a table set up with the parts and relevant parts and maint manuals, so that I can fit it all together. Monday's the day.
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