Norton roughness, chips, edge shredding, micro chipping

[Forzato]

Let's talk about the Norton embedded grit problem (aka Norton roughness, chips, edge shredding, microchipping, grit, grittiness, edge damage, etc)



Here's a copy of my email to Norton:

This is regarding a new Norton 4000/8000 waterstone... which I was advised is currently the benchmark in waterstones. The stone gets embedded with coarse grit from lapping (or the stone contains a coarse grit). The grit is far coarser than 4000 or 8000 and causes severe damage when using the stone. The embedded grit is not completely removable. I have spent m-a-n-y hours thoroughly, systematically and methodically eliminating other potential causes... it is unequivocally and without question the Norton stone. This stone has cost me many hours in restoring damage that it has caused (i.e.: chipping to precision edges, as viewed under a microscope). A replacement would be appreciated as I've heard that the symptom I'm experiencing is not an isolated incident. Thanks for your help.



Here are some historical threads on SRP regarding the Norton problem:

"Norton Roughness" by rustyblade
http://straightrazorpalace.com/showt...rton+roughness

"Pitted Norton 4000 water stone" by Oo.Mark.oO
http://straightrazorpalace.com/showt...ghlight=pitted

"Pockmarked Norton 4000" by smythe
http://straightrazorpalace.com/showthread.php?t=16072

"'feel' of the Norton 8k" by Bruno
http://straightrazorpalace.com/showt...shredding+edge

"Norton's shredding my edge" by JoshEarl
http://straightrazorpalace.com/showt...shredding+edge

"My Norton saga continues" by JoshEarl
http://straightrazorpalace.com/showt...highlight=pits

"Norton 8000... has this happened to any of you guys?" by coully
http://straightrazorpalace.com/showthread.php?t=6843



Some techniques I've used to eliminate the Norton as cause of the embedded grit symptom: L-o-t-s of water, 3m sandpaper, Norton sandpaper, 320 grit, 400 grit, 600 grit, 1500 grit, changing sandpaper frequently, light pressure, no pressure, lapping figure 8s, lapping circles, scotchbrite scrubbing, finger rubbing (until bleeding I might add), more rinsing with lots of water, frequent microscoping of edge when honing, grit picking, clearing stone of grit with backhoning, lapping with Kitayama, reading just about every post on SRP regarding this problem, watching Lynn's dvd repeatedly, using the Kitayama as the comparison stone throughout testing (as a 'control'), and last but not least... this post.

I have not used the Norton lapping stone - but the fact that the Kitayama tolerates sandpaper lapping without issue suggests the Norton should too.

I will post as Norton replies... until (or if) this is resolved I'll backhone with 1500 wet sandpaper on a marble tile and then final hone on a 12k Kitayama waterstone (which works quite well).

I wonder what true percentage of the Norton stones demonstrate this symptom... either way - please vote on this poll.

[Milton Man]

The main problem I has was little tiny bits of grit in the 4k sides (and very occasionnaly onthe 8k side) - all of this was remedies by rubbing the stone with my hand under water after I finished lapping it.

Mark

[Philadelph]

I don't know if this has ever been talked about- and it's just an idea mind you- but maybe sandpaper should NOT be used to lap a synthetic stone such as the Nortons? I use a DMT and have not had any problems whatsoever. Even particals from honing have not harmed my work. The stone definitely gets colored, even after rinsing, but I still haven't had problems. I'm guessing Norton would not recommend sandpaper, but that could just be to push their own product. Just a thought!

[Milton Man]

I use the Norton lapping stone...so???

Mark

[Forzato]

Mark (Milton Man),

Am I to understand that you have experienced the Norton embedded grit problem from using a Norton lapping stone?

[Milton Man]

Precisely - it somehow left either small grit or just very rough. Either way, rubbing the palm of my hand over the stone under running water eliminated the problem all together.

Mark

[jnich67]

Precisely - it somehow left either small grit or just very rough. Either way, rubbing the palm of my hand over the stone under running water eliminated the problem all together.

Mark

+1

I usually follow the lapping stone with a few light passes on 800 or 1000 grit paper. Then I use a scotchbrite pad to remove any residual grit. As stated, your hand works too.

Jordan

[Forzato]

Mark (Milton Man) & Jordan (jnich67)

It is quite interesting that you've experienced the Norton grit problem from Norton 's own lapping stone, albeit an easily resolved problem for you.

I have been unable to completely remove the grit despite the following:
...clearing strokes with an old razor
...backhoning (or honing for that matter)
...rinsing copiously
...finger rubbing till bleeding
...scotchbrite scrubbing till shredded
...cursing loudly till satisfied

Many times the stone seemed to be clear of grit... I'd get the razor to the point of a nearly correct edge... I'd go for that last bit and... WHAM - hit a piece of grit that chips the blade's edge so bad that 1/4 of the bevel has to be removed! ...my blood is boiling just to think of it.

I suspect that I may not be alone in this regard.

[JoshEarl]

It might be a defective hone. My first Norton had impurities in the 8K side that would chip out the edge every time it hit them. They were very good to deal with--sent me a replacement without delay.

Josh

[randydance062449]

I do not know if this will help but what happened to me was similar in one regard. I would be honing along just fine and then wham! I would hit a piece of grit. I finally figured out that the water I was dunking my hone in was dirty! So I switched to using a spray bottle of water to keep my hone wet and to wash off the surface occasionally.