Thread: Lapping Plates - Glass or Granite or somthing else?

Originally Posted by Goggles

Lee Valley sells mylar sheets that you're supposed to stick to their glass plate, it cushions the grit and cuts better. I'm not sure if it's supposed to protect the plate from wear, but I imagine it does at least partially.

Do you have the link to those sheets, i browsed threw the site but couldn't see them

Brighty , I think you'll find these techniques are best described as sacrificial. They are a means to an end & if you can maintain the granite with that big DMT you're ahead. I've got a piece of oven door glass I've used a while now & it has lost flatness but as I only use it with coarse powders & then finish with Atoma plates it's still useful as I get the flatness sorted along the way. I should toss it & that brings me to my next point. It's easy enough to get a piece of replacement float glass but it's not something that can be lapped like the granite. It's really a matter of what works best for you however Carbatec's site says about the granite plates. "Perfect for lapping tools or checking setups on small engineering projects. For longer life wet and dry paper can also be used as the grinding agent. "

Oh , in answer to your OP I don't think there's much difference in wear n tear between granite & glass. I think glass is harder & more durable but the granite can be lapped more easily. Again, your choice.

Thanks!

Have you ever used the granite? It seems to be a lot less harsh on my sharpening stones then the glass and the 600 or 400 grit seems to be taking out the marks from my 325DMT, not that the 325DMT really leaves any anyway lol.

My glass plate isn't very worn yet though, I'm guessing once that has a sand blasted feel all the way across it will be less harsh? I could be wrong...

I'm thinking i will use my glass plate for the 90 - 180 grits and the granite for 280 - 1200 grits for now.. Also, you said that you use the Atoma plates, are they better wearing then the Dia-Sharp plates? I have read that the higher end Dia-Flat plates wear really fast when used for lapping.. I also read that the Atoma plates are rated different to the Dia-Sharp plates and are coarser??

Also what about the veritas lapping plates, can they be used one stones and how do they go compared to glass and granite?

Originally Posted by onimaru55

For longer life wet and dry paper can also be used as the grinding agent.

I did see that but if the stone is intended to be used with the grits direct on the stone then i will see how it goes doing that, at least i know i can lap it now.

I have tested it with 5 stones now and the flatness hasn't changed, i have also lapped both sides of the granite plate now LOL

Originally Posted by Brighty83

Thanks!

Have you ever used the granite? Nope It seems to be a lot less harsh on my sharpening stones then the glass and the 600 or 400 grit seems to be taking out the marks from my 325DMT, not that the 325DMT really leaves any anyway lol. Yep I wouldn't say DMT 325 is scratchy at all.

My glass plate isn't very worn yet though, I'm guessing once that has a sand blasted feel all the way across it will be less harsh? I could be wrong... If my guess is right the glass is harder thus allowing the grits to work more on the stones but it shouldn't be "harsh" with fine grits.

I'm thinking i will use my glass plate for the 90 - 180 grits and the granite for 280 - 1200 grits for now.. Also, you said that you use the Atoma plates, are they better wearing then the Dia-Sharp plates? Very durable, So has an Atoma 1200 that's near 10 years old but its mostly for slurry raising now. I have read that the higher end Dia-Flat plates wear really fast when used for lapping.. I also read that the Atoma plates are rated different to the Dia-Sharp plates and are coarser?? They seem coarser because the of the pimpled surface but grits the same. They don't suffer from stiction as much also because of the surface.

Also what about the veritas lapping plates, can they be used one stones and how do they go compared to glass and granite? No experience with those.


I did see that but if the stone is intended to be used with the grits direct on the stone then i will see how it goes doing that, at least i know i can lap it now.

I have tested it with 5 stones now and the flatness hasn't changed, i have also lapped both sides of the granite plate now LOL

Seems to be working well for you.

This is interesting,

Veritas lapping instructions..

The lapping table (called a lap) should be softer then the part to be lapped. This allows the lapping compound (or grit) to imbed itself in the lap and abrade the object being passed over it

Originally Posted by Brighty83

This is interesting,

yes otherwise the grit will concentrate in the middle of the stone and dish it instead of lap it.
Japanese use what is called Kanaban, a soft iron plate that allows for the lapping grit to imbed in the plate.

Frankly lapping is a pretty straight forward process, that does not require more than a flat surface and sand paper, if one does not have a DMT.

Originally Posted by Brighty83

Do you have the link to those sheets, i browsed threw the site but couldn't see them

Here they are. They seem a bit expensive, especially since it's cheaper just to buy another one of their glass plates. I wonder how long the sheets last.

Originally Posted by Brighty83

Also what about the veritas lapping plates, can they be used one stones and how do they go compared to glass and granite?

The metal ones? There's a thread about them going on right now actually. *Edit: thread's been lost to the digital ether.

I am sorry, but I have got to say something...please take no offense, but worrying about getting (and keeping) a razor hone of any sorts flat to the 10,000th is a bit much. Your honing hand will not be able to keep the razor "perfectly flat and pressure perfectly even" to justify it. You are over complicating things. Sure, keep the stones flat, but do you ever hear of the old (meaning the highly experienced honers) honing veterans like Lynn mention anything like this? As long as your hone stone is as flat as your "certified" dmt, focus on your technique instead. There's my two cents anyways, take it for whatever it's worth.

As long as i cant feel the imperfections im happy but still.... If i can get it 99.9% flat i feel like i have achieved something lol

But I initially looked into this as a faster and easier way to flatten stones not a way to make them flatter then the DMT nor do i think this would get them flatter then the DMT. I will still be pulling out the DMT for quick fixes as the granite plate i got is almost 12kg and i'm not lugging that around everyday LOL

Wait a minute, you used a dmt plate to flatten a certified
granite lapping plate? If that is whay you ''did'', then I am
sorry, but your granite lapping plate isn't flat anymore.

The certified lapping plate when new is very flat, flatter
than any diamond stone. A floatglass plate isn't as flat
as a certified plate, but it is flat enough for our purposes.

If I understood you correctly, I am sorry to say that you have
ruined your granite surface plate. Even if your diamond plate
had a better flattness than your granite plate, you couldn't
use it to make the granite plate even flatter because the diamond
plate is much smaller than the granite plate.

Sharpman