Thread: Norton roughness, chips, edge shredding, micro chipping

Forzato:

What did the imbedded grit look like under magnification? I'm referring to the isolated grit particles found incorporated into the actual composition of your Norton stone. From what I've read in this post, you're absolutely certain these damaging and random objects are inherent IN the stone itself, rather than somehow, and from some undetermined source or sources.

Please describe those particles for me/us. I ask this because one of the first things I noticed about my Norton after I purchased a nice stereo microscope is how SOFT the surface is. You can so clearly see under magnification that altering the surface of the Norton 4000/8000 surfaces with a sharp metal object (tip of paperclip, tweezers, etc) is very easy to do. Look for the depressions under magnification in the 4000 side inherent in the manufacturing process and lightly poke at the "wall" of one of those dimples: A metal point scrapes the wall like a stick in wet sand. These surfaces are soft (try lapping a belgian blue for comparison sometime).

It's most certainly possible if lapping with a coarser grit sandpaper (and at the worst, lapping with non-wet dry sandpaper.....a huge and absolute no-no) that the sandpaper grit will release from it's backing and deposit into the surface of the Norton; especially in the surface of the more porous 4000 side. IMO, vigorous scrubbing of the surface after lapping in this fashion could result in accomplishing the opposite of your objective; rather than clean the stone, you could then be ramming and further setting the foreign particles into the surface of the Norton only to rear their ugly heads later. For all I know, the blood from your fingers could serve as an adhesive, further fixing those foreign particles into their places.

Can you take some pictures of these embedded particles and post them? If you don't have the means to do this, if you identify some of the particles while still in the surface, maybe one of us with a camera/scope set up could take the pics for you if you sent them your stone for evaluation?

Finally, I'd like to add a few additional bits:

• I never had any such problems with my Norton (those edges must certainly be beveled though, people, or similar problems can happen, none of which in that case are defects related to the stone's composition) and I did post as such in your poll.
• Although you make claim that you have the best intentions in mind in trying to uncover what you believe to be a broad scoped issue, in notifying Norton to improve their product quality and ultimately make our lives better in the end, I counter that your delivery and your assertion that the outcome of your poll is measurably significant smacks of a hidden agenda. I can only speculate from the many posts you've generated in a short period of time, but it's easy to see that frustration is emanating from your pores which in turn leads me to believe you're new at this. The road to BBS shaves and consistent honing of superb edges is most often paved with practice and frustration. Get used to it now. Everyone's abilities, experience level, time available, patience or lack thereof, materials and razors are different. It's quite likely you'll trash a whole slew of blades before you find YOUR best combination of razors, hones, strops and techniques
• When you refer to the Norton 4000/8000 stone as the "benchmark" stone, I'd like you to define that term in the context you're using it in here.

Lets let this rest until Forzato gets his new hone. I am pretty sure that the next one will be just fine. There are bad hones out there of most any kind, barber hones with lumps, coticules with cracks or signifciant veins of rough red particles, chinese 12K with coarse veins, arkansas stones with inclusions etc.. It is our job to help a guy determine what the situation is and that we have done in this case. Forzato is to be commended for the effort he has put forth trying to make this hone work. He has done all the right steps.

Now lets have some patience,

Actually a 95% CI for a population proportion can be calculated for any size sample > 0, although you'd want more than that, obviously. If you want a 95% CI to have a maximum width, say, then asking what sample size is necessary to achieve that width makes sense.

As it stands currently in the poll (7/30), an "exact" 95% CI for the population proportion of "problem Nortons", assuming this poll is a representative and independent sample from the population in question (a big assumption), is

(0.09933786, 0.42283652)

ie somewhere between 9.9% and 42%.

James.

Here are a couple pennies of mine: below is my email to Norton

My Norton 4000/8000 grit waterstone has small pits and possibly foreign matter embedded in the 8000 side. I have lapped it several times, but I still find pits using a magnifying glass. When sharpening my blades, I can feel the small bumps in the surface. Any suggestions?

Thanks, Mike Caraker

Norton's reply;

John,
It sounds like Michael has a faulty stone. Could you send him a new one to the address below?
*
UPC # 61463624336
*
Thanks..
Kris
*
Kris Spofford
Product Specialist
Norton Stones

I had been using the stone for about a month, had lapped it several times, with the Norton lapper, sandpaper, and a DMT (experimenting, I prefer the DMT). I tried most of the techniques in this thread for clearing the stone of grit, but nothing worked. I noticed small black specks on the surface, but couldn't feel them with wet fingers, but as sure as I'm here, every 3rd or fourth pass, I'd feel the bump, check the blade, and find a nick.
With a 20x magnifier, I was able to see the pits, and I'm sure they are the result of bubbles in the medium, a common problem in ceramics and plaster castings. The stone probably passed inspection at the Norton plant because the bubbles were all below the surface, they're uncovered by the action of the lapping. It's possible the bubbles are localized, and can be lapped out, but I haven't tried, maybe tomorrow...
I have another theory. As you pass the blade over the wet surface, the water accelerating under the blade causes rapid pressure changes; any foreign matter (trapped during lapping) in a surface imperfection (bubble) could be stirred up and ejected onto the surface, where it waits to be caught on the edge during the next pass.
The people at Norton were quick to respond, and I'd guess that this is not an uncommon problem, but probably not as common as the survey suggests.
Well, that's probably more than two cents. It's been a couple of weeks, and I still don't have my replacement.

Mike

yes i have small tiny rocks in norton that catch as blades slide over surface - norton said defecttive stone but this is second replacement stone that is no good

Originally Posted by Rayzor

yes i have small tiny rocks in norton that catch as blades slide over surface - norton said defecttive stone but this is second replacement stone that is no good

If you want to then send the hone to me and I will work on it to see if I can fix it, no charge.

But first, take a knife or old razor and run it over the surface of the hone 20-30 times and see if that removes the imperfections. That should be standard practice after every lapping of a hone.

Let me know,

OK guys, thought it was about time i spoke up, this is my experience with my new Norton over the past few days. Received on Thurs 21, then proceeded to lap with Norton w/d 280 then 600, which after that i thought I'd run my razor over it but then i encountered the small gritty feeling on BOTH sides of my 4000/8000. I immediately new this shouldn't be how it should feel so i did a bit more reading on SRP and came to the conclusion i should be finishing off the hone with finer w/d so i got some 1200, then i repeated first steps with 280,600 then went on to the 1200 and now when i use the hone it feels great( i also blasted it with water under the power shower). Altogether I'd say i did these steps about 8 times with each grade of w/d using the pencil grid, and now she feels like a dream. I hope this helps, good luck mark

Get a DMT-C 325 grit to lap and refresh both sides of the Norton and your "problems" will be solved.

David