Stone progression and lapping paper

[Richard Girvan]

I am still getting some marks left on the bevel after I have finished with my progression . It goes Diamond 100/200 , 400/600 , 800/1000 , then lapping paper 15 micron , 9 , 5 , 3 , 1 , .3 . Then Leather strops .250 micron / .125 micron diamond spray. Any ideas ? I was thinking of going to the 1200/ 1600 ceramic after the diamonds and then the lapping paper. What do you guys think ?

[Mark76]

Hi Richard,

Welcome to the forums!

What do you guys think ?

My first thought definitely was: you’ve got stamina :).

The progression you use should work to create a very sharp edge, provided 1) you have created a burr on both sides with the 100 grit stones and 2) you spend long enough on every stone/lapping paper to erase the scratches of the previous stone.

I think throwing in the 1200/1600K stones is smart if you want to get an edge to the level you seem to want to get it. The lapping paper I know (but I don’t know what you have got) is limited to edge-trailing strokes, which removes material much slower than normal stones.

If you use the stones, you can start using lapping paper of 3 micron. And spend the time saved on polishing the edge with each stone a bit more :).

Molecule Polishing: my blog about sharpening with the Wicked Edge

[Richard Girvan]

After a conversation with a guy who seems to really know his stuff I went back to my custom skinner and went back to the 1000 stones. I rubbed them together to smooth them off as we talked about. I then went (using very light pressure) and sharpened the knife from the front to the back to remove any chance of there being scratches from the higher grit stones and so I could see the effect that the 15micron paper had. After 150 strokes each side from the handle again with the 15 micron paper I can still see marks going the other way from the 1000 stones ??? And I did make sure to get a burr on the 100 stones when I started.

[Mark76]

This sounds familiar… I haven’t tried your lapping tape, but quite a few stropping compounds.

The confusing thing is that some of them are labeled “x micron”. This made me think they contained stuff that would be as abrasive as a stone with x micron particles (according to the grits comparison chart). Well, after some testing, I can say they all have their qualities, but they should not be used as if they were such stones. They are simply far less abrasive.

I would not be surprised the slightest bit if this were also the case for the lapping paper. It may work in the end, but even if it does, it will require a lot more effort than using stones. I recommend getting the WEPS ceramics.

Molecule Polishing: my blog about sharpening with the Wicked Edge

[Jende Industries]

There’s lapping film, and there is lapping film 🙂

One of the advantages of lapping film is how smooth the seem to make the edges – because the abrasives come loose and they are not renewable.

The quality of the film and the abrasives it uses will determine how well they cut after the 1K WEPS diamond (roughly 14 microns), as we’ve seen in the compounds threads.

With that said, I think the problem here isn’t the films, but the stones leading up to and including the 1K WEPS diamond. Something I call “Underhoning”, which you can read more about here[/url].

Just out of curiosity, what brand of films are you using, and what are the abrasives on them?

Thanks!

[Richard Girvan]

They are the ones that Tony Jackson sold me.

[TonyJ]

Tom

The lapping film Richard is using is 3M and is aluminium oxide except for the 5 micron which is silicon carbide. I have spoken to Richard at some length about his issue and it appears that there are 1000 grit scratches that are not being removed. I have used the same progression with the same film and achieved a pretty much mirror finish with no visible scratches under 30x magnification. I did try going from 1000 grit to 5 micron and found scratches left over, hence the back track to 15 micron which seemed to make all the difference.

Tony

[Jende Industries]

Hey Tony – good to see you here! B)

Yeah, it’s those darn left over scratches that get us every time! :angry:

[Author]

Posts