Thread: Naniwa's never lapped

Originally Posted by planeden

Nice STF,

Do the lower grits feel like the 12k? I'm still not sure I like the way the stone feels, but at least I think I'm starting to understand when it feels like it is don't its thing.

The lower grits like 1k,3K, 8K don't feel like the 12K.

The 1k is coarsest of course, but it doesn't feel like a 1k Norton, definitely smoother but It is still 1k and acts like one.

The 3K feels to me smoother than a Norton 4K, same with the 8K. The 12K is very smooth but I definitely feel it needs refreshing on a 400 plate before each use because it feels a bit like it might load up but it could cut more than you want with too much pressure so I wouldn't take my eye of the ball.

I don't use any pressure on the 12K anyway but I have heard that a person could squeeze a lot more out of it, if that means getting more than 12k from it I stand ready for instruction.

How a stone feels is very subjective, so better to look at the bevel and the edge. After 12k the bevel should be near mirror and the edge super straight. Look straight down on the edge to ensure the bevels are meeting fully. Hair test are not definitive.

Depending on what stone you are coming from, it may not hurt to use slurry on the 12k and do some circles to remove the previous stria.

If you see deep stria after the 12k that is probably 1k stria that was not removed during the progression. Any deep stria can end in a chip at the edge if not removed.

The issue with the 12k Super Stone is they load up, slurry will prevent some load up, but lapping the stone will clean it and give you a fresh clean cutting surface.

It is better to do circles in sets of 10 for a total of 20-40. This will prevent making a burr or at least make a smaller burr. Or do a lap reduction like the Ax Method to prevent making a burr. Circles are great for quick metal removal, like setting a bevel or the initial removal of the previous stone’s stria. Finish each stone progression with straight or X strokes on a clean stone to lay down an even stria pattern and straighten the edge.

Initial laps with slurry will make a rough edge, no matter the grit. Jointing the edge will remove any burr or flashing and straighten the edge. Then resurface the stone and wash off all the slurry and do straight or X strokes to lay down a new stria pattern. Here too doing more than 10 half lap strokes can raise a burr, so do half laps in sets of 10 or use a lap reduction, 10,5,2,1. Always finish with only edge leading strokes.

Probably what helped produce a good shaving edge is that he jointed the edge at each stage and removed the burr he was making with high count, edge leading and trailing strokes. You can make a burr and remove it and get a good shaving edge, but not making a burr or making a very small burr, (flashing) will make a stronger edge.

I always do alternate, finish X strokes after using Ax Method strokes to even the edge out and hone the heel and toe. My Ax strokes are not straight up and down but a slight X stroke. Glen has a good video on doing this in one of his bevel setting videos. I think it was the video on how many laps it took to remove a taped edge.

X strokes will prevent making a frown and hone the heel and toe. Also stropping on linen between stones will clean the edge and make a stronger edge.

Eventually if you hone a lot, you will feel the difference of a razor on a stone and learn to feel the moment you burn through tape. But that can take some time to acquire.

It is also a good practice to replace your tape, at least the top Kapton after bevel setting and again before going to your finish stone. If you have burned through your tape, you have lowered the angle and may not be honing to the edge. The more the tape wears the lower the bevel get, and all your honing may be waisted time because you are not honing the edge.

Changing tape is cheap insurance.

You do need to use some pressure with the 12k, but all finish laps on each stone should be with light pressure. The 12k can be a very aggressive stone with slurry and pressure but, can also finish well. Its downfall is that it loads up quickly. If you hone on swarf on the stone, the razor is not making full contact with the grit, (again not honing the edge) and can microchip the edge. A clean 12k should make a near mirror bevel and super straight edge.

Here is an old post on removing a chip with just a 12k Super Stone.

(12K Chip Removal/Bevel Setting)