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Lapping by a Monument Maker

As I sit wearing out my already beat up arm, I continue to stare at the chunk of granite I am using as a lapping plate. Got me thinking, why not get the monument shop owner of the place to work this puppy to flat-as-flat-can-be?
Anyone out there ever go that route?
 

duke762

Rose to the occasion
I suspect a monument place would only use really big machines and would have trouble mounting a stone for lapping. I think they lap from the top down instead of on a rotating plate to lap the bottom like a hone producer would. For really out of whack Arkies, I get brutal with silica (white sand) sand and concrete to get the party started. I've lapped out glue damage on the bottom of hard Arks this way. I assume you are lapping Novaculite of some kind. Nothing else would cause so much pain and frustration. I have felt your pain........
 
Sic powder works plenty fast. Although it can still take a while. Belt sander comes to mind. I never tried it. You try first and let us know. Lol. All kidding aside granite is less likely to split and is much harder than a typical jnat. I wouldn't . But its your stone.
 
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Slow but sure. Getting there
 
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After session #1 on the glass with some SiC of unknown grit (bag wasn’t labeled) we have gotten the Dota Creek stone this far. Next go around I’m wearing headphones.
 
When I had heavy lapping to do I always had good music on and at least a few pops to make it more tolerable. Looks good!
 
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Done (I think) the SiC, which I discovered was 60 grit, did a pretty fair job of flattening out both the Dota Creek and the Bethesda Black. Nonetheless it was a LOT of effort. Both stones were additionally lapped with a 150, 220, 400, 600 W/D progression.
Turned out OK I think. Next the real test......
 
I had a neighbor gave me a few arkies for free. And when I set them up to lap they were seriously off. So I never bothered using them. Lol.
 
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Done (I think) the SiC, which I discovered was 60 grit, did a pretty fair job of flattening out both the Dota Creek and the Bethesda Black. Nonetheless it was a LOT of effort. Both stones were additionally lapped with a 150, 220, 400, 600 W/D progression.
Turned out OK I think. Next the real test......

Definitely ain’t easy work!
The progression photos show the work put in !!

Did you check stones against a straight edge?
 
Do note that the 60-grit gouges are still present. They are very evident in the photos as light colored dots. Whether that will make any difference I couldn't say. It takes an awful lot of work to get them out, you'd need to make small grit size steps to do it efficiently. (Suggest loose grit at least up to 400ish) then you can switch to wet/dry with little trouble.
 
Plan is to run 120, 320, 600 grit (when the supplies arrive).
Actually...earlier today I ran a Brian Brown 7/8 in need of a tune up across the Bethesda then the Dota Creek. Significant improvement. A Jnat these are not. More like a coticule.
 
Plan is to run 120, 320, 600 grit (when the supplies arrive).
Actually...earlier today I ran a Brian Brown 7/8 in need of a tune up across the Bethesda then the Dota Creek. Significant improvement. A Jnat these are not. More like a coticule.
When you say they are not jnats. What does that mean? Because a jnat edge can be many things. Soft, hard, harsh, and anywhere in between. Same stone. Different technique to get whatever you want.
 
A monument maker is likely to far more concerned about polishing the surface than he would be getting the surface perfectly flat. However, if you have someone in your area who produces granite countertops, then he may have equipment that will produce a flat stone. However, he might have difficulty mounting something as small as a hone.

Using a piece of SiC wet/dry abrasive with a granite backing plate works quite well for initial flattening. After that, a diamond hone (DMT or Atoma) work well for maintaining flatness.
 
Yes. They are. But seeing as my blades really don’t cross that part of the real estate I just imagine they’re not there when honing. Figured I’d get to them some day
 
@buca3152 My only experience with Jnat edges has been one with a hyper keen personality.
All good. But not my preferred edge. I’m more of a coticule sort.
 
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