Thread: How do you lap your stones?

Wet and dry paper on my kitchen work top for me. Its cheap and effective for the few synthetics I own.
Job done

Forgive me if im wrong but ive always thought that if you use a low grit lapping stone on a finishing hone you would leave scratch marks on it which would reduce the effectiveness of it.

Originally Posted by markbignosekelly

Forgive me if im wrong but ive always thought that if you use a low grit lapping stone on a finishing hone you would leave scratch marks on it which would reduce the effectiveness of it.

I'm not entirely sure, I have heard this before from a fellow who works at the woodworking store I bought my hones from, but I haven't found that to be the case personally. I know several people who have used a D8C even on their really nice finishing stones (Gokumyo 10k and 20k, plus all their Naniwa Supers).

If you're particularly worried about using a low grit on a finisher then you can get a small D4EF or D6EF (4 and 6 inch extra fine grit DMTs) for cheaper than a full-size or just finish lapping some wet-dry to remove the scratches. It'll be a little quicker and more consistent than just using wet-dry on its own.

Again, I personally haven't felt a difference in the final edge after lapping my finishing hone many, many times.

Originally Posted by markbignosekelly

Forgive me if im wrong but ive always thought that if you use a low grit lapping stone on a finishing hone you would leave scratch marks on it which would reduce the effectiveness of it.

I have been using my DMT 325 plate for lapping all my Naniwa Super Stones including my 12K finisher and did encounter the infamous scratch marks in the beginning. Turns out that the DMT plates may have some high diamonds when new that need knocking down to rectify this problem. After I did that no further issues over the last couple of years. Would this be what you were thinking of? If you do a search like "DMT scratches" you should get quite a few threads on the subject.

Bob

I've been experimenting with silicon carbide powder recently as a polishing compound - i.e. used on mops. It's readiliy available in grits up to 1200 and does not cost much at all, so anyone worried abouit scratch marks on their hones could give it a try. I find it more effective and faster than using equivalent grade wet and dry but beware the lower grits will dish a marble tile so be prepared to replace whatever tile you use every now and then.

As Ive allways used wet and dry i haven't put much thought into lapping stones to be honest but seeing this thread piqued my interest.

Worn diamond plates are better for stone surfacing. New diamond plates are bad news for harder stones but not such a big deal for softer stones since the softer stones will give up particles and revert to their "default" surface pretty quickly. The diamond plates wear in over time and the individual diamonds round over/flatten to where they leave a much finer finish over time. Coarse lapping is a much bigger issue on harder stones like Arkies, Charnley Forests, C12ks, etc.

I prefer loose grit SiC on pretty much all but soft stones. It leaves a nice sharp surface that cuts well but if you lap to high enough grit still gives a very nice finish. Lapping a very hard stone with a worn diamond plate pretty much leaves you with a glazed over stone in comparison. It can cut a bit finer in some cases but also much slower.

If just lapping your synthetic stones between razors then I would use a diamond plate (have d8c and atoma 400&1200). If lapping harder naturals I would go the sic as you will kill the diamond plates and it will take ages with wer and dry.

Regarding scratch marks your right, the 120 I have does leave them and the surface of the stone is very rough, but the initial flattening is easy enough, I have the atomas that I use for cleaning up these scratches. But 4 atoma plates is heavy. thats about $400. 4 pounds of sic and a $5 granite tile would be enough to lap for a long time. Ive seen it sell for as low as $15 for a grit. So 4 grits is a little more than half of 1 atoma, Now I always did my initial lapping with wet/dry on hard naturals, and the plate dies anyway. Not complaining though but I was expecting to get more out of it.

I use a well worn dmt 325 grit on all my hones, synthetic and natural. A thing to note is diamonds are the hardest material known to man, so using them to flatten hones is not going to "round" them, ever. What is happening is they are breaking loose from the steel plate they are attached too. I think a lot of people who say they have completely killed a diamond plate really havent. I could be wrong, but I've used the heck out of mine, and it is still very good at flattening hones. I use the same dmt to hone razors that are severely chipped and also on knife blades that have rough edges. I personally will never fool with sand paper, tiles, Sic powder etc. The diamond plate is always flat, and lasts a very long time. As previously stated, when it is brand new you should always use it on something other than a hone to knock off all the "loose" diamonds. Just my opinions, YMMV.