Possible issue with shapton pro 320

S

Spartan00

Joined
Feb 4, 2016
Messages
1,329
Hey guys got a problem . Used my shapton pro 320 about 3 days ago . Normal routine I used it rinsed it and put it in the case to dry out .

Just now went to grab it and I open the case , stone didn't dry properly in the middle of the stone is a wet spot say 2 silver dollars in size . In that wet spot the stone is soft . It's not breaking down or anything but can this be fixed ? What should I do if anything ? If it dries will it harden back up?
 
Shaptons are known to have an aversion against anything else than water. If you involuntarily transfered oil on the stone this will lead to a permanent soft spot. Terpentine or other thinners work similar, even soap is on Shaptons No-Go policy. If it is permanently, try trueing it until the soft spot disappers. Higher grid Shaptons don't soak up water deep into the stone if they are used properly with Splash&Go or five minutes soaking max. A few 1/10 mm might give you a new an uncontaminated surface.

But have you tried to let it dry outside of the box? I don't put my stone in the box after use, i put it in a shadowy, temperate place with enough air (inside my room) and let it dry for one or two days before returning it into the box for storage. Maybe it's just water, the box doesn't provide much chance to let it dry completely if you put it into a drawer.
 
I've never had the situation you described ... like hein31, I dry my stones out for a couple days before storing them. I usually have them leaning against the kitchen sink backsplash so the water drains off. Thank You for the "heads-up" of what can happen when these stones dry, I'll keep a focused eye on them and see if I ever have a duplication of what you had on your 320.

Another thought, how do you like the 320? I have the Shapton Glass 120, 220 and 500 and wonder how the 320 would be to work with.

All the best.
 
I love the pro 320 . It cuts like a new dMt coarse .

They say the glass is newer technology and it cuts super steels faster etc . I have 320 pro 1k 4k in glass so I haven't tried a glass in the same grit as the pro .

I will say I've been satisfied with the steels I've used the 320 on . Love the feel of the stone and it's really versatile. You can either have it as muddy as any stone or hardly any mud just depends on how you use it . Also the 320 pro lasts forever
 
From what I remember, the difference between the pro and the glass stones is the binder and the glass backplate. When the pro was exported from Japan, depending on the climate and humidity a stone could arrive broken or with fractures. The Shapton pro stones generally are brittle, but still hard compared to a Naniwa SS. The smaller grids have the problem, that inbetween the big particles you have enough space to soak much more water than the finer stones. Surface tension of the water prevents it from flowing into smaller cavities, so normally the higher grid stones dry out faster.

The drying process can be a hazard too: if you live in hot arid climate zones (Arizona etc.) heat can dry out the top surface faster than the still soaked inner areas. This can lead to drying cracks and in the end lead to a broken stone :eek: . To much air flow and direct sunlight are equally hazardous. Never soak any shapton too long, this can solve the binder an lead to a permanent weak spot, even when dryied out :grumpy: . Never use other fluids than water, no oil, no solvents, no soap, no chemicals. :thumbdn:

Shapton adressed the problem with a commercial rework: they glued the stones to a glass backplate, which prevents broken stones at delivery. This too prevents the underside of the stone from soaking up any water, so a crack completely throughout the stone is very rare without mechanical accident. I have no idea, to what extent they changed the actual recipe for the binder, they seem to have a different choice of gridsize, but still, people with the "too quick" drying problem claim their stone devellops small cracks in the surface.

People in temperate climate zones often use the Kuromaku series, which to my knowledge is the japanese original to the first pro version for export purposes. These stones have little problems, if you handle them properly. A big problem is that no matter what stone you buy, usually the instruction paper for all known hazards to the stone is in japanese. So even if you belong to those few who read instruction manuals, it makes no difference since most people still cannot read japanese... :rolleyes:
 
Last edited:
Spartan00 said:
I love the pro 320 . It cuts like a new dMt coarse .

They say the glass is newer technology and it cuts super steels faster etc . I have 320 pro 1k 4k in glass so I haven't tried a glass in the same grit as the pro .

I will say I've been satisfied with the steels I've used the 320 on . Love the feel of the stone and it's really versatile. You can either have it as muddy as any stone or hardly any mud just depends on how you use it . Also the 320 pro lasts forever
Click to expand...

.

Appreciate the feedback ... exactly what I've been wondering, is a 320 like a DMT Coarse?

The micron is similar with a Shapton Glass 320 - micron 45.94 ... DMT Coarse 325 - 45 micron ... cannot readily find the micron of a Shapton Professional 320 ... would think it close to the Shapton Glass.

The Shapton Glass 220 is a bit gray in color and "grittier", the SG 500 is white and "much smoother" .... I'm thinking the SG 320 may be the "what I'm looking for stone". It would be neat to compare the Professional model and the Glass model side-by-side. Someday, I'll have to get a professional stone just so I know the difference between the two series of stones Shapton products.

All the best.

.
 
I really like the pro stone , it absorbs water where I read the other pros don't. Also love the slurry off my 320 . I kinda wish I would of got all pros instead of one pro and 2 glass stones .

Some say the glasss are supposed to be better with harder steels Than the pros. The pros are no slouch .it's one of my favorite stones to sharpen zdp-189 with
 
hein31 said:
From what I remember, the difference between the pro and the glass stones is the binder and the glass backplate. When the pro was exported from Japan, depending on the climate and humidity a stone could arrive broken or with fractures. The Shapton pro stones generally are brittle, but still hard compared to a Naniwa SS. The smaller grids have the problem, that inbetween the big particles you have enough space to soak much more water than the finer stones. Surface tension of the water prevents it from flowing into smaller cavities, so normally the higher grid stones dry out faster.

The drying process can be a hazard too: if you live in hot arid climate zones (Arizona etc.) heat can dry out the top surface faster than the still soaked inner areas. This can lead to drying cracks and in the end lead to a broken stone :eek: . To much air flow and direct sunlight are equally hazardous. Never soak any shapton too long, this can solve the binder an lead to a permanent weak spot, even when dryied out :grumpy: . Never use other fluids than water, no oil, no solvents, no soap, no chemicals. :thumbdn:

Shapton adressed the problem with a commercial rework: they glued the stones to a glass backplate, which prevents broken stones at delivery. This too prevents the underside of the stone from soaking up any water, so a crack completely throughout the stone is very rare without mechanical accident. I have no idea, to what extent they changed the actual recipe for the binder, they seem to have a different choice of gridsize, but still, people with the "too quick" drying problem claim their stone devellops small cracks in the surface.

People in temperate climate zones often use the Kuromaku series, which to my knowledge is the japanese original to the first pro version for export purposes. These stones have little problems, if you handle them properly. A big problem is that no matter what stone you buy, usually the instruction paper for all known hazards to the stone is in japanese. So even if you belong to those few who read instruction manuals, it makes no difference since most people still cannot read japanese... :rolleyes:
Click to expand...

Well said, and welcome... stick around and chime in whenever you want. The more knowledgeable people the better.
Big glass fan here. Cut faster and less delicate to work with. You can use them right down to the glass if you keep them lapped. (Ask me how I know...)
Russ
 
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