Re: A source of cheap precision cast iron plate
William Duffield, on the Cohansey
>Do you have an Enco part # for this thingy?
I have a couple of concerns regarding cutting up iron castings for this purpose. LIke wood, metal castings have internal stresses, due to such factors as variable thickness of different parts of the castings, and differential cooling rates. Cutting these castings up into smaller pieces can release these internal stresses, causing the pieces of the castings to move, and messing up the precision of the surfaces. You may have to regrind them after cutting them up, if you want a flat surface.
The cast iron side wings are webbed on the underside, for strength and to reduce weight. They are full thickness only around the perimeter. This allows holes to be drilled through the side and bolts, nuts and washers used to attach them to the cast iron main table and to attach rails, etc., to them. If you cut one up, the pieces will be far from flat on the bottom, probably no flatter than an inverted #8 sole.
When I suggested cutting up your table saw a couple months ago, my tongue was in my cheek, for just these reasons. Sorry if my warped sense of humor misled anyone. OTOH, if you find a busted #8 sole at the flea market, it might be a cheaper place to start to get to a cast iron sharpening plate. In either case, you will have to figure out something to bed your casting in to give you a flat base, maybe plaster of paris or putty or gorilla glue in a wooden tray?