Lapping oilstones with SIC powder

[Slim7]

Hi,

Does anyone else have the problem of the SIC powder getting embedded into the pores of oil stones when lapping? I know its hard to get out. Any suggestions on how to remove? I mean i keep my grit refreshed and after some time i rinse off and apply new grit when too much finer worn SiC gets into the mix. Its awful especially on the Norton Indias.

 

[willc]

I have flattened more than a few vintage India stones with SiC grit and never had any problems with this.
You may want to try a stiff wire brush.

India stones are by far the most time consuming stones I have ever refurbished. Some of them are extremely hard and they will take 30 grit down to a fine slurry in no time but even with stones with more open pores I never had problems with embedded grit.

 

[RadialBladeworks]

Hi,

Does anyone else have the problem of the SIC powder getting embedded into the pores of oil stones when lapping? I know its hard to get out. Any suggestions on how to remove? I mean i keep my grit refreshed and after some time i rinse off and apply new grit when too much finer worn SiC gets into the mix. Its awful especially on the Norton Indias.

Yeah man, I now only use SiC powder for lapping the stone. I picked up a diamond truing tool for truing grinding wheel and use that to refresh the stone's cutting surface. Works extremely well and you never have to deal with a loaded surface from the lapping powder. Just gently scrub the surface of your stone and she cuts good as new

 

[FortyTwoBlades]

For India stones consider a cheap ~$50 Chinese-made large diameter diamond lapping plate. You can get big 12" discs in various grits without a hole in the center and they work well for the task.

 

[Slim7]

For India stones consider a cheap ~$50 Chinese-made large diameter diamond lapping plate. You can get big 12" discs in various grits without a hole in the center and they work well for the task.

I have read another guy on here uses a diamond labridary disk? I can't seem to find the thread now??? If they are that durable then they would be worth the money. I do like to keep my stones reconditioned on SIC powder , although its messy. Finishing stones dont need 'flattening' much just reconditioned and that only takes 30-40 seconds. But coarser oil stones need flatting once every year or two, more depending on the bond of the stone and also how much or how often you sharpen. Reconditioning i dont mind. but lapping i dont like, especially on really hard vitrified stones. I dread it at times... A really hard India can turn 30 grit SIC into dust quick!! Anymore i think 60 grit is sufficient enough even for heavy lapping.

 

[FortyTwoBlades]

It was probably me, honestly. I'm the only fellow I've seen using them, but you can find 'em on the big auction site quite economically as long as you don't mind waiting for 'em to show up. Nice and big for full size bench stones. I mostly use the loose grit method but having the disc available is handy regardless, and I use it often.

 

[Slim7]

It was probably me, honestly. I'm the only fellow I've seen using them, but you can find 'em on the big auction site quite economically as long as you don't mind waiting for 'em to show up. Nice and big for full size bench stones. I mostly use the loose grit method but having the disc available is handy regardless, and I use it often.

How thick are they? flat? Link or where do i buy them?

Seems like i may have read your post, but the other fellow said you could get them at Kingsley North..

 

[Slim7]

It was probably me, honestly. I'm the only fellow I've seen using them, but you can find 'em on the big auction site quite economically as long as you don't mind waiting for 'em to show up. Nice and big for full size bench stones. I mostly use the loose grit method but having the disc available is handy regardless, and I use it often

I wander how tough the bond is?

 

[FortyTwoBlades]

That one's an example, yes, but posting links to active auctions isn't permitted so you may want to edit that out to save the mods the trouble. Haven't had any trouble with the bond strength but have worn one out before using it to lap a fair amount of natural stone and sintered ceramic (pro tip--loose diamond powder works better for sintered stuff.)

 

[P_A_S_1]

Just curious, is there anything wrong with rubbing two stones against each other instead of using loose grit on a plate?

 

[UncleBoots]

Just curious, is there anything wrong with rubbing two stones against each other instead of using loose grit on a plate?

I know the classic answer: yes, there is something wrong with that. But if you have three stones, then it's OK. But I forget why. Something about how two stones can conform together into not-flat but complementary shapes. I get that part, but why three stones fixes it, I forget.

 

[P_A_S_1]

I know the classic answer: yes, there is something wrong with that. But if you have three stones, then it's OK. But I forget why. Something about how two stones can conform together into not-flat but complementary shapes. I get that part, but why three stones fixes it, I forget.

OK, thanks. I do this sometimes after cleaning the stones but wasn't really sure if it was good practice or not. Need to look a little deeper into it as I don't want to do more harm then good.