Edge Pro Matrix resin bond diamond stones

Diemaker said:
No that is not normal, I just put a few of my stones together resin to resin and there is no gap. I have to go to EP this afternoon anyway so let me look into this and get back to you. When did you get these, who did you get them from and where are you? Do you have some calipers? I would love to know the thickness of the stones on both ends and the center, 3 measurements per stone.

I just talked with Cody and he's going to take a look too.
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I am from Czech Republic and have buy it from the Dictum Company from Germany (94447 Plattling) around week ago.
I don't own a precise calipers with 2 digits after comma, i get one and come back with info tomorrow
 
Thank you, where you bought them helps us determine when they were made. The thickness of the 250 may be off some from one side to the other, the diamonds get in the way of the reference surfaces, so all I need is the thickest measurements.
 
Diemaker said:
No that is not normal, I just put a few of my stones together resin to resin and there is no gap. I have to go to EP this afternoon anyway so let me look into this and get back to you. When did you get these, who did you get them from and where are you? Do you have some calipers? I would love to know the thickness of the stones on both ends and the center, 3 measurements per stone.

I just talked with Cody and he's going to take a look too.
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Hello,

I have divided/marker the side of the stone with 4 points (Image 1):
1639660_original.jpg


after that I pressed the clamps of the caliper near as possible to the surface of both sides of each stone in 90 degree angle (image 2)
1639915_original.jpg


and here we have following results:

1639335_original.jpg


So the 650 stone have a difference of 0,05 mm on one side and the 250 stone have difference of 0,04 - 0,08 mm from the middle to the end.
If you will need for future investigation my purchase document I can gladly sent it to you via E-Mail or to Cody.

Thank you in Advance for Help
Vladislav
 
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Great! These numbers remove all of the guessing, and it's not nearly as bad as the light gaps looked. The target thickness of the stones before dressing is 6.35mm, .250 inch, so your not far off. Although the ends shouldn't be thinner the difference in your stones will not be noticed while using them. In my tests differences in stone thickness are not noticeable until around .37mm with the 1100 and finer stones, with a 2.5mm, .1", bevel. The 250 or 80 is less sensitive to differences in stone thickness. If these were my stones I would mark the thickest and thinnest spots of the 250 so when I needed to dress it I could focus a little more where it is thick during the next 15-20 dressings and then measure it again. Granted if you are sharpening a lot of knives this will take a year or more because the 250 rarely needs to be dressed, unless you use too much pressure when sharpening. When dressing them you should not remove any diamonds, only resin, so they should not change in thickness from dressing, when done correctly. A maintenance dressing should only take 15 seconds or so for the 650 and maybe 20 seconds for the 250, assuming your using 240 grit, 55 micron, brown aluminum oxide. Other abrasives work too but the brown alox will last the longest before getting ground up too fine to do anything.

Not that this helps you but the 250 and 650 stones I measured at EP last night didn't taper at the ends like yours, but some of the 250s did taper from one end to the other as much as yours but that is from molding not dressing. What caused the thin ends on your stones is a worn-out lapping plate, they get dished from too much work in the middle and not enough on the outside edges. I have already talked with Cody about this this morning and I am going to work with them on this some more.

Out of curiosity have you measured your Venev stones to see how much they vary in thickness?

I don't need proof of purchase, knowing where you got them helps us figure out when they were made. Since Dictum gets one or two orders a month it didn't help too much but from the machining on the back of the 650 it looks to me to be probably from the last batch I delivered to them which was the first part of September.

I am sorry about this but it really shouldn't affect either how the stone works or how long it lasts since you typically wear the centers faster than the ends.
 
Thank you a lot for taking time and checking your material and detailed explanation. I will make some test on some steels and if you want a can show later the results.

The Venev Stones are are already dressed and I write the number tomorrow.

KR
Vladislav
 
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Your welcome and I would be interested in your thoughts comparing the two types of stones.
 
D Diemaker A friend of mine seen a video of a guy using a Mister Clean Magic Eraser to clean your Matrix stones and did it very well,my friend said he tried Bar Keepers Friend on your stones and it didn't work very well for him.

Post your email here and I'll email you the video I can't link it because it's in a facebook group called edge snobbs but I can download the video in a small format and email it to you.
 
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D Diemaker I sent the video to, xxxxxx, that's your email correct.


(Email address removed by "Blues")
 
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Thank you for the email BUT POSTING MY EMAIL ADDRESS HERE WAS WHAT I WAS TRYING TO AVOID!!! Please delete it!!! Crawlers search these sites to add addresses to their spam lists.
 
Oh thank you, thank you, thank you!!!!!!!!!!!!!!!!!! Blues, you're a life saver!
 
Sorry about that Diemaker I didn't mean anything by it and I just wanted to make sure I got it right in case I didn't,I wasn't sure why you put it up the way you did and I just wanted to clean.
I didn't know about the crawlers,if I would have seen it sooner I would have deleted it but I had to deal a friends problem all day oh joy.

Diemaker said:
Thank you for the email BUT POSTING MY EMAIL ADDRESS HERE WAS WHAT I WAS TRYING TO AVOID!!! Please delete it!!! Crawlers search these sites to add addresses to their spam lists.
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wade7575 said:
Sorry about that Diemaker I didn't mean anything by it and I just wanted to make sure I got it right in case I didn't,I wasn't sure why you put it up the way you did and I just wanted to clean.
I didn't know about the crawlers,if I would have seen it sooner I would have deleted it but I had to deal a friends problem all day oh joy.
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I figured as much but Forums are notorious for getting crawled for email addresses to add to bulk lists that are then sold. That is why you see so many post their email addresses in such strange ways. By the way, I never did get your email. I don't know why because you did get it right.
 
I'll try sending it again,I didn't get anything saying the email din't go threw witch I have in the past all the time if I messed up the email,did you check your spam folder.
Email has been sent,if you join edge snobs on facebook you can see it under one of Scott Gunn's posts.
 
If I purchase the 80 grit stone, is ocean beach sand OK to use for maintenance dressing when the time comes? Can I just use the stuff that fills up my shoes when walking up and down Cape Kiwanda? Is there any reason to get a $5 bag of 60 grit silicon carbide when I order the stone? I will probably reprofile just a couple of knives per year, so using something that breaks down quickly is not a problem. I have a ceramic floor tile in a cardboard box already to go, and it even has a plastic bag liner.
 
Beach sand has lower hardness than silicon carbide, will have variable grit size and generally be much finer than 60 grit, and has rounded rather than angular particles. Its' going to break down more quickly. If it works it's going to take you longer to dress your stone.

If you're only going to use that stone a few times a year a $6 bag of silicon carbide should last you many years.
 
Thanks David,
In Diemaker's May video he said that 60 grit isn't nearly coarse enough, 36 is close and works OK, but coarse sand is the best. I found bags of coarse sand but do not need 20+ pounds, so thought about the beach. I thought sand was basically all the same. Now I know that it is not! I will try the 1/2 pound bag of 60 grit silicon carbide for maintenance dressing. If it doesn't work well I will buy the coarse sand and put most of it in the garden.
John
 
Beach sand will work. My first tests were with some sand I got at a local spot along the road to one of the nearest towns. Other than it being a little dirty it worked fine. I find the sand lasts much longer than sic. I and EP curently use pool filter sand which is pretty smooth, $11 for 50lbs locally. 60 grit sic is best for the 250 but sand works too. As long as you don't use too much pressure you may never need to dress the 80 or 250 stone, I don't. If you do use the backside of your tile and save the flatter side for the finer stones. You will need to get some 240 alox for dressing the 650 and finer stones. You can clean them with alcohol, Bar Keeper Friend, Comet, or Ajax but nothing works as well as dressing them with the 240 alox. Don't be shy about dressing the stones, at the rate you use them they will last a couple of hundred years.

A little trivia, Ben started out using beach sand before switching to sic.
 
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