Why would one buy Glass Stones (GS) when there’s already an amazing collection of stones you can buy for the EP? Up till now there were the stock EP stones and tapes, Naniwa Chosera stones, Shapton Pro stones and various natural stones. Is there an absolute need for another series of stones? No. Is the there a use for these stones? Definitely YES! There’s a niche where these stones excel and they are great all round stones.
The GS were never available on the EP because it was pretty much impossible to custom cut these stones without shattering them. Ken Schwartz tried cutting a few with good results, but the majority of them were a nightmare to cut, so the Chosera and Pro stones would be the only ones available for now.
If Shapton would make these stones without the glass base, it would have been a lot easier to cut and they would have been available right away. Sadly Shapton never agreed to make this an option. A year goes by without any progress on the issue, but then Mark Richmond persuades Shapton to make a cast for EP stones and make a few test stones. When delivered, I got the email from Mark to test them out. I immediately accepted!
I’ve heard a lot of good things about this stone before I used it. I have a 320 Pro stone and I imagined it would be similar. I wasn’t wrong here. The 220 behaves very similar to the 320, but doesn’t produce such a black slurry like the 320 does (probably just because the 320 is a blue stone). Other than that, the finish and speed of cutting is very similar on every steel I tried. It had no problems with the harder abrasive resistant steels I’ve tried (S60V, CPM D2, CPM S35VN and Fallkniven’s 3G). The difference between the Pro and the Glass stone is marginal in my opinion.
This is where things get interesting. The Shapton Pro stones get a bit weird above 2k when used on very hard and / or abrasive resistant steel. Their feedback is a bit strange as it feels like you’re sharpening on plastic. This feeling didn’t bother me much because on the EP the weird feedback isn’t that much of a problem. However, the silky creamy feedback was a lot nicer on the 4k than the feedback on the 5k. Even though there’s not a very big grit difference between the two, the 4k left a cleaner edge faster on the hard and wear resistant steels. On carbon steel (like Aogami super, white steel or 52-100), it was hardly noticeable. I would say the GS did the work 20% faster than the Pro stone.
Pretty much the same story here, but much more noticeable in this case. The plasticky feel of the 8k Pro is much more noticeable than it is on the 5k. This didn’t affect performance, but the feeling just wasn’t nice. The Naniwa 8k Snow White was a good alternative, but that stone needed soaking unlike the Shapton stones.
The 8k GS is by far the best of the 3 stones I tested and provided a nice creamy feedback that resembles the 8k Snow White but feels even better in my opinion. It’s also a lot faster and produces a bright mirror finish.
These stones are perfect all-round stones for the Edge Pro in my opinion. It handles everything a Pro or Chosera stone would and performs better on very hard and abrasion resistant steel. If you’re new to the edge Pro, and you want only 1 set of stones, I’d strongly suggest going with the Glass Stones!