Thread: "Sledge" my new lapping plate...

Originally Posted by JimmyHAD

Scott, I don't care for the powder aspect. I would prefer the diamonds.

Agreed.

Aside from the possible contamination of previous grit paste left on the lapping plate, I am concerned about eventual dishing of the cast iron plate. Wouldn't the abrasive cut both ways?

Anyway, I'm sure the smart people at Shapton have already figured all these problems out, but I'm still paranoid.

I don't think I would want to use powder, either. I used to operate a Blanchard Grinder with diamond imbedded tips on very hard refractory products and I use my DMT diamond plates to lap most of my hones. Imbedded diamond particles rule.

Originally Posted by Leighton

Agreed.

Aside from the possible contamination of previous grit paste left on the lapping plate, I am concerned about eventual dishing of the cast iron plate. Wouldn't the abrasive cut both ways?

Anyway, I'm sure the smart people at Shapton have already figured all these problems out, but I'm still paranoid.

I wouldn't be surprised if the cast iron plate did
not guarantee the same flatness as the DGLP or
DRLP...

- Scott

supposedly what happens is the grit embeds into the plate and then it cuts the softer stone. If you think about it though these plates including the DMT ones are not meant for lapping a one piece stone like maybe some of the arkansas stones since they are basically a huge piece of abrasive but on all other stones sedimentary and artificial ones where there is a binder over abrasive that plate should last several lifetimes as long as you use the proper abrasive diamond powder will actually cut more of the plate being a harder and more aggressive medium.

I've had the shapton lapping plate for some time now. The carbide powder works great and the plate is hard, very hard. I used it to grind down beryl which is almost hardness 8 and I was afraid it would wear the plate but the plate was untouched. You really need to get some extra fine powder to put a real polished finish on your hones. Also the plate is dead flat. If it wasn't I wouldn't want to even think what it would take to make it flat.

Wow! I'm sorry I went to sleep and missed all the fun

OK. 1. The compact plate is *only* flat to a tolerance of +/- 8 microns, compared to the +/- 3 microns for the DGLP and DRLP. For the money, it is still "flat". Don't forget 25 microns is .001", so the plate is still 3x more precise than industry standards.

2. My skinny plate is 5 years old and gets A LOT of use - we're talking about lapping the 320 pro after each and every knife/tool, and the #220, which takes a good beating on cleavers and other kitchen knives. (Admittedly, since I have the DGLP and DRLP, I have reserved my compact lapping plate for only coarse grit stones, but in the beginning, I used it for everything.) As for flatness, I placed my old one on top of the new one, and there were no visible gaps between the two plates. A crude test, but I figure after all that lapping, the old is still looking quite flat.

3. The lapping powders make lapping a little more messy than using diamonds, but they will not embed in the Shapton stones. You will need to rinse off any grit on the surface of the stone you just lapped before sharpening, though. You can even use the medium powder on a fine grit stone and it won't embed. I never had the need to try coarse powder on a fine stone, but I still doubt it would embed itself. You'd see a big honkin' scratch in the surface of the stone, though! I have lapped other water stones with no problems, too. Oil stones are not recommended.

BTW - I always suggest lapping backwards from fine to medium to coarse grits, to avoid cross contamination. I go in this order: 5K, 8K, 15K, 30K - 1k, 1,500, 2K - 120, 220, 320. This also means you don't have to clean the plate off too much as you lap, and the previous stone's residue will actually help the next stone to lap.

4. For razor sharpening only, I would have to say that the DGLP is much more desirable because it is quick and less mess, and unless you use a stone below 500 grit, you can get by with just the DGLP. However, for a lapping plate that is still quite precise, it is more affordable and can lap the entire range of just about any water stone.

5. I haven't used the new plate yet, and because of my crazy schedule these next 2 weeks (I'm taking a summer coarse), it looks like I won't be able to try it until the last week of August. I do imagine it will perform just as well, though. The bigger surface area should speed up the process since the stone will have more contact with the plate.

I think I got to everything.

this is one bad a$$ flattener