Cleaning diamond stones

He's a good shot of the effectiveness of BKF. These are 3 EZE-Lap diamond slip stones I use in machine shop work. They are in varying levels of wear. The left most one is quite worn out, the middle is fairly worn and the right side one is fairly new. You can see the difference in swarf build-up pretty clearly in the before photo. The left two are worn enough to be quite fine, so they don't collect as much steel. The right one is quite aggressive still since it's still new and it collects quite a lot of swarf as you can see by the embedded black steel.

20180906_214144.jpg


Apply BKF paste. Wait for 5 minutes.

20180906_214159.jpg


Scrub with a plastic dish scrubber sponge and rinse thoroughly. Et voila, hones are free of embedded steel.

20180906_214217.jpg
 
Ok. I can tell from experience. I have many electroplated diamond plates. Some I use for sharpening and some I use exclusively for flattening. I have a #140 Atoma that I use only for flattening and I can confirm that the plate is getting matt spots in places. I have checked with a microscope and the matt looking spots has no diamonds and nickel. #400 plate that I only sharpening on has no bald spots and #1200 that I use for sharpening and flattening has a few tiny spots. So logically we could assume that constant contact with abrasive is affecting the plates coating to some level.
Also, we should keep in mind that different plates are made differently and react differently. Usually, cheap plates have 1 layers of diamond/nickel coatings. Expensive plates will have at least 2 layers. I believe Atoma has 1 layer, but a high-quality one because of the pattern they use.
 
All electroplated diamond plates have only one coat. By it's nature there is no possible way to have more. Diamonds are set in place while the nickel is being plated, which locks the diamonds to the plate. Most likely the diamonds are kept "in solution" by the electroplating solution being agitated as the plating occurs. Some companies use a short electroless plate in the beginning to lock the diamonds down then switch to electroplating to build up the nickel layer a bit more. If enough nickel were plated to allow a "second layer" the original would be completely embedded in nickel and the overall flatness would be compromised. Only enough nickel is deposited to lock the diamonds in place and set them at a certain depth, leaving the tops of the diamonds exposed.

The diamond products that have more than one "layer" are those with resin or metal bond. These are a whole different animal than electroplated diamond products. These are produced by mixing a resin or metal binder with diamond grit and sintering it. The item is placed in a mold and heated while a press applies a high level of pressure to form the product.

The Atoma plate is most likely plated while a "shield" plate with a pattern of holes is in place over the substrate. Once plating is completed the patterned shield plate is removed and the finished product removed from the bath.

The better these plates are kept flushed and clear of abrasive particles, the safer they will be and the longer they will last. With coarser grit plates the diamonds stand proud of the nickel substrate farther since the diamonds are larger, so by their nature they are somewhat safer from erosion. However, using them to flatten abrasive stones can still remove diamond if they're allowed to build up a thick "mud" of abrasive particles from the stone being flattened. Keep them flushed!
 
I totally agree with everything except the first sentence. I will not argue with you because of my poor English language and lack of time. Here is a picture of two sample plates. On the left is 100/80 and on the right 50/40 micron. The one on the left has two layers of abrasive. If you would look under the microscope you would a see the top layer of diamonds and nickel coated blops in the first layer. Of course, the flatness is compromised somewhat. These are test samples for big diamond files we are working on.

plates.jpg
 
Anything CAN be done... That doesn't necessarily mean it's a good idea. None of the established makers do this - because of that compromised flatness. I've never seen or heard of a multi-layer nickel electroplated diamond plate or any other tooling. Most electroplated tooling is designed such that it has a specific geometry - in other words, either flat or in a specific shape. Plating the nickel thick enough that more than one layer of diamond is attached means that flatness can not be controlled. Not good for most users. Often it's bad enough with one layer - look at all the stray deep scratches most diamond plates leave when they're new due to the stray large grit. That extra layer means your scratch pattern will be all over the place and will have a LOT of stray very deep scratches.

For rough work on a knife it may work fine, other than the fact that it will take more work to clean up the mess on subsequent stones; but I think you will find that you lose diamonds from the substrate pretty quickly doing it that way also. Additionally, once your top layer is wiped out, it will probably take quite some work to expose the bottom layer. Nickel holds considerably tighter than sintered bonds. That's exactly why all established makers who make multi-layer diamond tooling use sintered bonds.
 
Last edited:
Well, I know for a fact that many companies are making multilayered el. plated wheels and other tools. Sure they are not for precise grinding applications but they do exist. Anyways we are way off topic. But I you are right about the plates. I guess I had a brain fart. I was 100% sure in my mind that DMT is using some kind of multilayer coating technology.
 
Good thread, I am learning a lot about this subject. Over 99% of my experience with plated diamond tools is brazed, this helps me understand why diamond plates are so comparatively cheap to my brazed tools, and it is not volume. Like I said earlier I did try electroplating a few of my tools and had no problems with the bond eroding, the diamond and bond was around .015" thick so several layers of diamond and very lumpy. I have only been thinking of the ops 100 grit plate with anything I have said.

eKretz - Is the nickle used in DMT and similar diamond plates pure or an alloy?
 
Slightly off topic, but I thought I would share, hopefully to help others and save their diamond plates. I had a brand new DMT DiaSharp 1200 mesh (EF) plate. Like many others have noted, and has been documented quite well, the surface of that plate had larger diamonds scattered throughout, and made for a very unpleasant sharpening session. So much so that the 600 mesh (F) plate made an edge that felt a LOT sharper. Sent it back to DMT for a replacement. The replacement stone had the same issue. In my infinite wisdom of ignorance, I decided I would use that 1200 plate to "lap" my Naniwa Green Brick 2000 grit Silicon Carbide stone, in hopes of knocking off those high points. I only lapped for a short time, and it took off quite a bit of the diamond surface. Both the "proud" diamonds and the "smooth" good surface. My lesson:
Don't use DMT plates to lap waterstones. They may be more affective on AlOx stones over SiC, but I wouldn't do it. One caveat...the 120 mesh EEC stone...that one will lap waterstones quite well. The diamonds feel like they're quite large and really stuck into their bond, and there aren't a lot of them compared to the other plates in the series. Sorry for the slight thread derail.
 
Diemaker said:
Good thread, I am learning a lot about this subject. Over 99% of my experience with plated diamond tools is brazed, this helps me understand why diamond plates are so comparatively cheap to my brazed tools, and it is not volume. Like I said earlier I did try electroplating a few of my tools and had no problems with the bond eroding, the diamond and bond was around .015" thick so several layers of diamond and very lumpy. I have only been thinking of the ops 100 grit plate with anything I have said.

eKretz - Is the nickle used in DMT and similar diamond plates pure or an alloy?
Click to expand...

If you've successfully done this, you'll already know that the process is a little more involved than my earlier description. It isn't likely that you'll find a good description of method and process for any current operations - this info is considered proprietary. It is my understanding that the best electroplated tools are those which are at least begun with electroless nickel - as those deposits can be hardened with a heat treatment process. In the few operations I've been exposed to there are usually several plating steps prior to nickel/diamond plating and a lot more in the last bath than nickel.
 
Nice one. I'll raise you one. The "new" eze-lap. Check out the range of diamond size. You can understand this if you think about it. When they use mesh to separate, long diamond pieces that are the right diameter can still get through. To help done guys who aren't familiar, remember: thousandths of a millimeter are microns, so these sizes are basically read as microns if you remove the decimal point.

EZE%20F%20New%20Ring%20Light_1.jpg


Here "slight wear" - notice the diamonds are mostly rubbed flat with the nickel, but still there:
EZE%20F%20Slight%20Wear%20Ring%20Light_1.jpg


And here, a ring light shot of "holy Ishtar."
EZE%20F%20Heavy%20Wear%20Ring%20Light_1.jpg
 
Last edited:
You must log in or register to reply here.
Back
Top