Thread: Lapping pressure

I have a nicely lapped stone. I received some advice to try lapping after 30 minutes of honing. If I am to do this with a norton flattening stone. What kind of pressure should I be using.

I ask because I had trouble getting the factory surface off of the stone and the stone flat with the norton before and wondering if my technique is to blame. I soake the Norton and the lapping stone for about 20 minutes, then I simply rub the stones together back and fourth with light pressure. I sually do this for a couple of minutes.

I have a dovo and a wapieinca that I am trying to test on arm hair. They will shave arm hair but not quite pop them at the tops and since I have this nice hone I want to try and get them as sharp as I can. I am shooting for the hanging hair test as I have not had a razor pass this test yet, and my blade seems to dull quite quickly during a shave.

I've never had trouble lapping with the Norton FS. I use just enough pressure to keep the stones in solid contact. I also do this under running water. I don't know if this would help in your situation or not.

Jordan

I recently obtained both a Norton 4000/8000 stone and a Norton FS. Both are new. I soaked them both for about 20 minutes. Then a drew a grid lines every inch and on both sides if the stone. I used a back and forth combined with a circular motion on mine and it seemed to work great. The gridlines disappeared relatively quickly. I used light pressure with the Norton FS on top.

Maybe Josh will post his advice here. I am interested to see just how much lapping he did on my hone to remove the factory surface. I lapped that stone 5 or 6 times and did not get the surface off. Although I was not aware it needed to be removed.

Originally Posted by jbovee

I used light pressure with the Norton FS on top.

I think you're meant to take the hone to the flattening stone and not the other way around. Hence the grooves in the Norton FS which channels away the slurry/swarf as it abrades. (The instructions that come with the Norton FS might indicate this?)

I use a fair amount of pressure. More than light pressure. Takes the surface off very quickly. I find I need only a minute or two of steady firm lapping before I'm done.

I'm chiming, I'm chiming.

I haven't used the flattening stone, so this will be based on my experience using sandpaper, my old Norton 1K and now my DMT 325...

Lapping matt's hone with the DMT probably took five to 10 minutes. I didn't keep track, but it was a while. I think it takes a little more work to remove the factory surface. I seem to remember lapping my Norton 4/8K for 30 minutes or more when I first got it. I used the pencil grid method; it was pretty un-flat, so it might have taken more work than average. I think I was using 600-grit sandpaper, which probably prolonged things. The factory surface seems like it might be a little harder than the rest of the hone. Re-flattening it will probably take just a minute or two.

I'd say that you need to use some light pressure, but don't try to muscle it. The hone weighs about two pounds, so just pressing a little bit should be adequate. I liked the suggestion about using enough to keep the hone in firm contact with the flattening stone.

In Lynn's video, I think he's actually holding both the flattening stone and the Norton combo in his hands. If you do this, you can turn the hones on their side and rub them together under running water. That's how I lapped when I was using my Norton 1K to refresh the surface on the 4K.

Don't be afraid of ruining the stone. Even if you somehow messed it up, you could still lap it flat again. You'd just waste a little bit of hone. Nothing to fret over, given that there's thousands of razors' worth of material there...

Use pencil grids for a while until you have a sense for what the surface should look and feel like after it's flattened. Now I can usually tell if a Norton is flat by towel-drying the 4K side and looking at it from different angles. Also, honing will leave steel deposits on the hone. When the black gunk is gone, you're usually done.

Does that help?

Josh

I have been trying to get a nice sharp edge back on a Dovo 5.8ths and am having trouble on the 400 sidde of the hone. It seems the blade is catching on the hone once again which I am assuming means it needs to be lapped. I have been lapping it today and am not having any luck and have dulled my razor to boot.

Any help?