more Info on diamond lapping plates

Re: couldn't agree more

steve knight

>it depends on how much you need to remove. my japanese irons need to be ground flat as they come with a hump they are done on a surface grinder.

I do most all of the work on soft 0-1 but I get irons back from ehat treat with nicks in the edge. so I jsut use the same setup I used to grind them in the first place.

But, heat not an issue.....

Bill Tindall, E. TN

>with hand grinding. I have tried 60 micron on acrylic and it cuts very agressively. Didn't have material to try smaller. Oil based paste didn't charge well in very fine grit.

fine grit diamond and acrylic

Tim of San Leandro

>"Oil based paste didn't charge well in very fine grit."

Bill,

My guess is that acrylic isn't hard enough...the smaller size diamonds embed completely so that no cutting edges are exposed....whereas the 60, 45, 30 micron or so large size diamonds only embed partially in acrylic.....it would make sense with my findings using the cold rolled 1018 carbon steel plates.

I find the coarser grit diamonds are wearing away the steel lap - evidenced by the abrasion of the lap surface - whereas the fine grit diamonds show no signs of polishing the lap surface - evidenced by the maintainence of the original 120 micron scratches on the laps....so perhaps the best might be to employ cast iron or acrylic for coarse grits and something harder like the 1018 steel for the finer grits. Your thoughts?

Tim

Graphite phase of grey cast iron

David Barnett

>I was told that grey iron was especially durable and efficacious for lapping because of its intrinsic spheroidal graphite, which acts to both 'set' or bind the initial charge of fractured abrasive crystals while lubricating against dislodging assaults, further exploiting friability by capturing newly refractured abrasive particles.

Re: Graphite phase of grey cast iron

Dan Donaldson

>Wanna say that in English? ;-)

(firmly tongue in cheek;-)

Point taken... maybe I should try 'metaphor'

David Barnett

>Lapping Crystal

by Nolan Voyd

You could tell she'd been in the bad part of Iron City before. She had that sharp angular look that comes from being bounced around, from place to place, man to man. Though she may've been hard, she wasn't used up. Not by any stretch. No, she still had a figure that'd make a bishop kick out a stained glass window.

...to be continued

Just wonderful :-)

Lyn J. Mangiameli

>

As usual David,

Bob Hackett

>You have a way with words.

When you said metaphore,I thought it was in the context of "Hey,Billy-Ray,What ya` gonna use that Meta` for?".

You caught me completely offgaurd,I can`t wait for "The rest of the story".

Mainely,Bob-Who is beginning to like at least some southern humor.

Flattening Steel Plates

Don Thompson, Cutler Ridge, Florida

>If I understand correctly, you lay sandpaper on a granite reference plate, and lap the steel plates on that? Any special tips on technique?

Thanks.

Re: Flattening Steel Plates

Tim of San Leandro

>no..just like planing a board face true - do it carefully. I take one or two careful passes - push on the end, not from the top of the plate and start the push slowly. Look at the scratch pattern and you'll know if you should try the other side or not. It is like truing the sole of a plane - but it may take longer depending upon what you use for tha lapping plate.

A bit of spray adhesive on the sandpaper...and plenty of solvent to clean the granite afterwards.