Thread: Gokumyo 20k consistency

I lapped the top side and it is uniformly white. The off-white layer on the bottom didn't appear until I had used the hone for a month or more. I recall that I thought it was just a patch of swarf that needed to be lapped away, but instead of shrinking it grew larger. I think this also explains why I had such good results early on and rather inconsistent results more recently.

Mine also has dark yellow streaks on the bottom where it rests on the rubber base.
I wouldn't mind betting it's staining from the rubber.

Originally Posted by onimaru55

Mine also has dark yellow streaks on the bottom where it rests on the rubber base.
I wouldn't mind betting it's staining from the rubber.

I was thinking of that possibility myself, though as of yet I only had a bit of black staining as zib described on his. No yellow yet , but as I noted before, I haven't been using it much.

Would also explain the very geometric shape of the discolouration, perhaps?

James.

Originally Posted by onimaru55

Mine also has dark yellow streaks on the bottom where it rests on the rubber base.
I wouldn't mind betting it's staining from the rubber.

The bottom of mine has never been in contact with the base. It came packaged separately and I have always set it bottom side facing up.

Whatever the stain is, it was either not improving or even reducing the HHT from a Shapton 8k. I just touched up a TI on the 8k and then the newly lapped top of the 20k and there was a clear improvement in the HHT. I will shave with it in the morning...

I HAD been suspecting the 8k to 20k was to big a jump and now have a 16k GS in the mail from Stuart.

Mine came on the rubber base and was stuck to it. I don't remember any yellowing, but I did lap the bottom to get rid of the sticky surface. I also decided to use the bottom to hone and to preserve the upper stamped side. I've never used the rubber base after unpacking it. Now the stamp side which is down and was white has yellowed along the length of the stone. The upper lapped side is a clean white.

It does sit on a steelex stone holder which has 3 rubber pads that are a similar rubber, but the yellowing isn't just at the contact points of the pads which are stationary, but its all across the now lower stamped side of the stone and also on the sides.

Edit: Based on gadaiver, post #18, mine is a second generation too.

The label side was slightly yellow before lapping but the pure white surface was exposed very quickly.

What I am seeing on the bottom is not yellow, but more of a mottled off-white texture. I should add that I have removed about half a millimeter of the bottom between yesterday and this morning, so this is not a surface stain.

This is what I received from Stuart regarding the different generations of stones:

The newest stones are third generation. First were fixed to their rubber bases and the original type, the second was introduced for uniformity with the rest of the line-up and featured a stone not solidly fixed to it's base. The third generation are the same, but the stone itself is wrapped in plastic by Suehiro due to some problems we discovered with the stone/base being in contact with each other between manufacture and delivery in the second generation. It seems that the stone in contact with the rubber base absorbs something from the rubber, and can cause some inconsistent performance in the side of the stone that was in contact with the base. So long as you use the 'up' side exclusively, you shouldn't have any problems of any kind.

I've got a second gen stone. I've never used the logo side and that side did absorb a bit of black/gray staining from the base. Works well so far on any razor I've used it on. Of course at that grit level I only take a truly shave ready razor to it for final enhancement. Trying to get to shave ready with such a stone, whoever makes it, is not the correct approach IMHO.

Originally Posted by JimmyHAD

I was thinking of that possibility myself, though as of yet I only had a bit of black staining as zib described on his. No yellow yet , but as I noted before, I haven't been using it much.

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The only staining I ever noticed on any stone was some black and yellow stains in the 4k side of my Norton 4k/8k combo. No staining on either side of the Gokumyo 20k.