I'm not so sure, Paul... *PICS*
WoodburnBob
>...about the generalizability of "lapping = convexity". It's possible that you and I are merely members of a race of men for whom that's true in certain circumstances...using certain methods and techniques...and in our present uncertain state of development. I don't completely discount the idea that you or I might someday emerge from a cocoon and fly off with the others.
[Paul Womack thinks he hijacked the earlier thread on my infill rehab. Actually, this issue of "lapping" is an always seductive topic for me. Thus, I've hijacked his hijack into a new thread so that if anything truly profound comes out of the fog it won't get missed.]
There was a ton of "Pond" posts on this topic in years past characterized by much testimonial and no consensus. Even here and now, various WC members routinely describe or imply the "flattening" either of plane soles or of cutter face/backs by, in effect, lapping. I often wonder if 1) they are somehow simply gifted, or 2) they never bother to put a good straightedge inspection to their work. Either way they seem happy with the outcome.
Just last night I needed to true up a water stone. In effect, I lapped the stone against an EZE-lap diamond plate. In less than 2 minutes I could wring them together so tightly Hercules himself wouldn't separate them by pulling. I lapped the sole of the Spiers plate flat...I thought...on the cast iron lapping plate. I lapped it smoother with a 123 block wrapped with abrasive paper. What I can't seem to do successfully is use what amounts to the "Scary Sharp" method to get things flat.
In one of my more masturbatory experiments a couple years ago, I lapped 3 plane soles together in the tradition method of "originating" a flat surface: abraiding A to B, B to C, C to A in long series of iterations. I wanted to see if it could be done. It seemed to more or less work.
Three ordinary block planes:
I've marked these with a little tag of tape so I don't mix up A and B and C. Clover compound, for those of you who don't know it, is basically SiC in grease. It comes in various grits. If you recall the look of this workbench from the infill pictures, this is the bench surface 2 years ago. Appalling, eh? Incidentally, for those who don't recognize it immediately, that odd looking, gray, pre-Columbian mother earth looking object is a hunk of clay. At the time I thought I'd model the next generation ergonomic plane handle, become rich and famous, and retire to a secluded paradise. I dropped the idea when I realized I'd get lonely, bored and paranoid.
There may be intervening photos, but I don't find them. This is the result of an hour or so of A/B, B/C, C/A rotation of rubbing the soles together (like rubbing your hands together on a cold day). A little dab of Clover compound is all that's used as abrasive. Every once in awhile I'd clean and spot the three of them to see how much progress I'd made. This is probably where I stopped.
I think this was poplar.
A nice piece of mahogany.