Norton 4K/8K first lapping

I just did the first lapping on my new Norton 4K/8K. It wasn't even close to being flat. I had to lap 1/16" to 3/32" of material off before I got it perfectly flat on the 4K side. Same on the 8K side. It took hours to lap this thing and I didn't even finish the 8K side. I still have two opposing corners that are still rough but I got tired of lapping it. Enough to hone my razor though as long as I stayed away from those corners. I used a DMT Duo Sharp with the coarse side rated at 325. The one that's perforated with the plastic in the middle. Also tried 325 wet/dry sandpaper on granite.

Is this normal for a first lapping? Should I get a different lapping hone? Does anyone use the Norton lapping stone? To me it seems they could have gotten it a lot closer to flat than that. The stone actually rocked back and forth on the diamond plate!

Anyway, I honed my razor using pyramid method and then a few laps on CrOx on felt paddle and shaved with it. Got a good shave from it. I was impressed by the polish the 8K left on it. It leaves more of a mirror finish than the PHIG I got from Woodcraft. The PHIG leaves more of a satin finish.

Should I get the Naniwa 12K? Will I notice a difference in smoothness of shave?

Sorry your initial lapping took so long. I'm not sure what to say about that. I would highly recommend the Nani 12K. It will turn a good shave into a great shave. I threw my PHIG in the trash.

You can get a Naniwa to polish up past the 8K if you want, but you don't have to. Totally up to you. I like mine :)

I had to lap my 4/8 Norton quite a bit on both sides too. Not quite as bad as yours it seems. I have read that us Str8 razor peeps are the only ones that need them perfectly flat. We are a small portion of the market, the knife guys are fine with them as they come out of the box.

I got a Norton 1k/8k combo a couple years back to sharpen my hand plane blades and think I remember having to lap it quite a bit with the same Duo Sharp (I don't think it's the DMT). I lap my Norton before and after I use it, but it stays very flat. I used the same Duo Sharp for a couple years until it wore out then I got a DMT 325 and like it better because it's heavier; however, if you lap it in random circles or figure 8's instead of just back and forth then I both will work just fine to keep your stones flat, in my experience.

I got the Naniwa set (3, 5, 8, 12) for my razors and use my 1/8k Norton for bevel setting. I love the Naniwa 12k and certainly don't believe I'm able to get the most out of it and I feel like I get really sharp, smooth shaves out of the Naniwa 12k then 7 laps on CrO3 on a strop or .50 diamond on felt then leather. I practice on 3 of my 4 razors every day using different stones, slurries and finishing techniques and when I want to "zero-out" my razor and feel what a sharp, smooth shave feels like on that razor for reference, I finish it on the Naniwa 12k, CrO3 or .50 diamond and strop. When I am trying to practice finishing, I try to finish a razor on my Naniwa 8k to feel like my 12k. I haven't touched my C12k since I got the Naniwa.

Hope this helps.

The dmt325 is a little slow for initial lapping IMO. It will do very well for subsequent lappings and leaves a smooth surface, ready for honing.

When I get a new stone I start on the norton lapping plate. It's very fast and channels away swarf. Then I grid-lap again using the dmt for a nice smooth surface.

Michael

I had a similar situation when lapping my Norton 4K/8K for the first time too. I also used the DMT 325 for lapping, and still do for all of my stones. Nowadays, when I sharpen razors I do a quick lap of each stone. My 8K still has a corner with a rough edge, but I stay away from it.

After reading various posts over the last month, I'm considering getting a Naniwa 12K as a finisher. That should smooth the edge from the 8K.

I'll probably get the Naniwa 12K since it gets so much praise here as a good finisher. The edge did feel really sharp but maybe a tad harsh for my face off the 8K.

My diamond plate has seen a lot of use setting bevels on hand planes and chisels so it is probably getting pretty worn. Wish I'd gotten the Norton lapping plate before I started. I may get it anyway with the Naniwa 12K. Or I see that Naniwa has a lapping plate that's less expensive!

I lapped a Norton the other day. The 4k was easy ~ the 8k took 20 mins on a 140 grit Atoma.
That seemed a long time. ;)

Yeah, my diamond plate was pretty worn but I didn't want to wait to hone my razor. A couple hours is a pretty long time to lap😄

I just got my 4/8k in the mail today, along with the DMT 325 to lap it with. I've never honed a razor before but I have some coming from ebay to practice on. I pulled the stone out of the box and couldn't believe the rocker on it. The long tail cats around here were scared and run off. I wanted sent it back but I guess this is normal and I'll wait a little bit and read some more, get my stone lapped eventually and see what honing is about. Thanks for the info everyone!

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Originally Posted by Roso

I just got my 4/8k in the mail today, along with the DMT 325 to lap it with. I've never honed a razor before but I have some coming from ebay to practice on. I pulled the stone out of the box and couldn't believe the rocker on it. The long tail cats around here were scared and run off. I wanted sent it back but I guess this is normal and I'll wait a little bit and read some more, get my stone lapped eventually and see what honing is about. Thanks for the info everyone!

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Well, sorry to hear yours had a lot of rocker too. But glad I'm not the only one. It's just hard to believe they can't get them a little flatter than that. Even though straight razor users might be a small percentage of their market I know woodworkers probably comprise a good percentage. And as a woodworker I have to have my stones perfectly flat to sharpen plane blades and chisels too! I wouldn't even take a knife to that stone out of the box! At least you have a brand new diamond plate so hopefully it won't take you as long to lap.

Good luck!

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Originally Posted by Jetmech

Well, sorry to hear yours had a lot of rocker too. But glad I'm not the only one. It's just hard to believe they can't get them a little flatter than that. Even though straight razor users might be a small percentage of their market I know woodworkers probably comprise a good percentage. And as a woodworker I have to have my stones perfectly flat to sharpen plane blades and chisels too! I wouldn't even take a knife to that stone out of the box! At least you have a brand new diamond plate so hopefully it won't take you as long to lap.

Good luck!

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IIRC, Lynn mentions in one of his vids that it's a more recent occurrence that the norton 4/8's need more lapping when new. Who knows what the reason for this is, maybe a manufacturing process that changed?

I went old school and got the the Norton 4/8 and lapping stone. I got a king 250/1000 for setting bevels too. Guess I got lucky because they all lapped rather quickly. 8 months or so later and I still shave off the 8k. After a good strop of course. I have about 30 razors now all from e-Bay. Some had chips and others were almost ready. It hear it wasn't too many years back and this was the best you could do for a straight. I am about ready to pop for a finisher but I think I am going to go for a Zulu grey.

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Originally Posted by Jetmech

Should I get the Naniwa 12K? Will I notice a difference in smoothness of shave?

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The #1 thing about this Art of Using and Maintaining a Straight Razor is; PATIENCE!!

First and foremost, you have the cart before the horse!!!

You need to learn to properly strop, lather and shave with a straight razor before you even begin to think about learning to hone!!

Honing a straight razor is Not an easy thing to do ‘PROPERLY’!

The Naniwa 12K is a Wonderful tool, but until you can get nice and constant edges off of the Norton 4/8 you will be wasting your money, time, energy and steel!!

I don’t mean to discourage you as in fact I’m trying to encourage you to take your time, learn step by step how it all ‘works’! It will all come together!!!

Please don’t try to Run a Marathon, before you learn to walk.

I give my counsel from my own experience! I waited for about a year and a half before I took the leap to learn to properly hone a razor!!

I’m so glad that I did as I had acquired ‘baselines’ as to how the razors felt honed by a Pro. Today I can either come close to or match those original edges!

Take you time, step by step!

Anything more that 5 - 10 mins with a 325 DMT to lap, is way too much time. Your DMT is probably trashed, it happens. Yes they are diamond coated but not bullet proof.

+1 on the Atoma 140, great for lapping new stones and major razor correction. Post 140, I go to the 325 to get it smooth, make sure you use lots of water, either submerged under water or under running water. If you lap not under water you will destroy a new Diamond plate. A few licks to raise a slurry is one thing, lapping for minutes is another. Sixgun has a good video on lapping.

Smooth is more important than flat, dead flat. The razor is only ½ to ¾ wide and only on that much stone at a time, that the entire stone is “perfectly” flat, does not matter. Smooth is what matters, and that is what Lynn was talking about in that Norton thread and video. As you lap with a DMT on a synthetic or any stone you can feel the rough spots in the stone. Once it is smooth, it’s good.

Chances are if you are new to honing you won’t know what that feels like, so don’t grind off the top 1/4 inch of stone. Get it smooth and relatively flat and start honing. If it needs more to come off, you will feel it in the razor. The feel and sound of the blade on the stone should be the same across the whole stone.

Don’t forget to chamfer or round the edges each time you lap the stone or slurry, 1 or 2 strokes. If you don’t, you can develop a ragged edge that will rake across your razor edge with each x stroke.

I imported a set of 20mm Naniwas on stands from Japan and they were pretty flat. Two of them had a slight recess where the sticker was.

The 8k is fairly dense but not sure why was taking so long. I have used 220 wet dry sandpaper in the past with good results. As far as your phig stone, I think a natural stone should leave more of a satin look to the bevel. I just recently switched to Nani 12k, wonderful choice and it gives you a very polished finish if that is what you are looking for. Oh, it puts a very nice edge on it as well.

Thanks for the replies. I'm not new to honing, just new to honing razors. I have lapped stones before and yeah it shouldn't take that long I know. I have King water stones that were pretty flat to begin with and took no time to lap. And yes I could easily tell when the stone was getting smooth. It was just really fat in the center and thin on the ends so that the lapping plate rocked. I had to lap that much off just to get a workable surface because stone was really rough. In previous post I mentioned that I didn't even finish lapping. Good stone once you get it near flat but that's ridiculous even though my diamond plate was worn.