DMT course/fine and Shapton questions.

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d.weglarz13

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Jun 4, 2008
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Okay, weird question.

First, I have some Shapton glass waterstones at 1000 and 2000 grit that I never used yet, but got them about 3 years ago, been sitting in a drawer. I know, heresy. But, the ceramic seems to be very rough and dirty, I guess just mostly from sitting around and gathering debris.
So, can I flatten and smooth out the grit to bring these back to brand new with my DMT Course or Fine stone? Like I said, they are never used, just rough and dirty.
Or, if that won't work, I can do sandpaper on granite, but what grit to flatten and smooth both of these?


Second question. Over the years of using my DMT uninterrupted Course and Fine bench stones, they have taken on a somewhat very light surface rust discoloration. Im guessing its probably from not drying the stones every time after I used them.

What can I clean these up with? I have used brake cleaner in the past to get them clean after use, maybe not the best idea, but I heard it somewhere and seemed to be fine and work well, and didn't change the discoloration at all. Any ideas on what will take off the rust color? Its only very light, and only in some spots on both DMT stones. I was thinking WD40, but Im thinking I already pushed my luck using brake cleaner a bunch of times in the past, and don't really want to hurt the stones since i know they are only supposed to take water and not oil.



So, any suggestions on how to go about cleaning my stones light discoloration?
And, flattening (okay, more like smoothing and cleaning) my new but old Shapton glass?


Thanks guys for any and all help. The discoloration has been bothering me for a while, so much that Im thinking about getting a whole new setup. More for the reason of needing to spend my money burning a hole in my pocket, but the discoloration adds to it I guess.

Thanks again

Dave
 
The first thing that I would try with the water stones is an old toothbrush and warm water. If that isn't enough, the DMT plates will work. 320 git wet/dry, used wet on flat granite or float glass will work as well as anything.

Get the rusty look off of the DMTs just by using them! And always dry them after cleaning! (As you now know, I'm sure:D)
 
I wouldn't use the fine DMT, the coarse would work but I'd make it a last resort as it'll be very hard on the DMT plate. If if does come down to that make sure you do it under running water (just under water isn't as good as under running water).
I use the cheap diamond plates from harbor freight to flatten my [spyderco] ceramic stones so I don't put the wear on my DMT's.

As for the rust issue, I've only ever had to deal with it once, I used some old honing oil I had and just rubbed with a rag, after that time I made sure to never let it happen again, now I thoroughly dry the plates each time and store each one wrapped in paper. Is the rust on the diamond surface or just on the sides/bottom (or do you have 2 sided stones?)
 
The rust is only on the surface, not the sides or back. Weird I know. Also, used brushes and won't come off. I was thinking oil or wd40 but can I use that if these are only for water?
 
With waterstones of alumina/ceramic grit, assuming these normally shed whole abrasive particles like all other waterstones, I'd think twice about using a diamond plate to flatten/lap them. If grit particles are coming off whole in the lapping, they might damage the nickel substrate of the diamond plate. This is different than flattening a fused/sintered ceramic hone (like the Spyderco hones) in the same manner, because the hone's firmly-fixed grit particles won't be shed whole, but instead are slowly (very slowly) abraded away, interacting more with the diamond itself, and less with the nickel supporting it.


David
 
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You could just get a pack of 3M in 320 grit, use it soaking wet on a flat surface, and it will work wonders on any water stone.

I use the full size sheets on float glass, the stickion from the water holds them in place like glue, and a "figure 8" motion with very light pressure, and the stones look like, and cut like new.

I do use my DMT plates on stones that are starting to dish out a bit. Haven't had a problem with that, but it removes grit faster than sandpaper, so for just touching up stones, I mostly use sandpaper, or SiC powder on float glass (That makes a nice mess to clean up though if you're as klutzy as I am.).
 
For the rust on the DMT's I would just use Dawn and a toothbrush to scrub it clean, I find this works for light rust in general.
 
Okay great. I was just wondering if the 320 was too course for the 2000 grit shaptons.
I will use the sandpaper on the granite. Thanks again for your help guys.

this has been bugging me for a good while now, and finally decided to try to clean the dmt's and smooth out my shaptons.


dave
 
No it's not too coarse. By changing the grit you use to flatten the waterstone you can drastically affect how fast it cuts. It will also somewhat affect the finish you get.
 
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Would it be a better idea to use the 320 on the 1000, and maybe 400 on the 2000 or something like that? I am still a bit unclear on this.
I am not sure the pros/cons to actually changing the finish of a stone, like anything around 2000 grit I would think should stay the same grit as was designed to be? Help? I think I may have confused myself more now.

dave
 
No you don't want to get anywhere near the same grit as the stone. This abrades the stone down way too smooth, and prevents the stone from cutting well. A coarser diamond plate to lap is much better. I would prefer to have too coarse a plate rather than too fine. This opens up the stone and allows it to cut much freer. Aside from this you need the diamond to protrude far enough from the plate that the slurry of abrasive from the stone you're lapping doesn't abrade the nickel matrix holding the diamond in and remove it. On very fine diamond stones if you try to lap a waterstone you will destroy the diamond plate in short order. For this reason I also always lap my stones with the diamond stone upside down on top and under running water, so the "mud" gets rapidly washed away.

The same thing happens when you dress a grinding wheel in a machine shop with a diamond dresser. If the diamond is traversed too slowly across the wheel (this would be like a fine diamond lapping plate for comparison's sake) you get a very fine finish with the wheel but it takes forever to remove any metal and burns the surface easily because there's a LOT of heat produced due to high friction. If the diamond is traversed too quickly the wheel really removes material quite amazingly fast, but may leave irregular lines behind in the surface finish. Get the traverse speed (or lapping plate grit) just right and you have a great finish and good material removal rate. I like to use either the XXC or the XC DMT plates on my Shaptons. XXC for resetting bevels, XC for finishing and finer stones. My finest is 15,000.
 
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eKretz said:
No you don't want to get anywhere near the same grit as the stone. This abrades the stone down way too smooth, and prevents the stone from cutting well. A coarser diamond plate to lap is much better. I would prefer to have too coarse a plate rather than too fine. This opens up the stone and allows it to cut much freer. Aside from this you need the diamond to protrude far enough from the plate that the slurry of abrasive from the stone you're lapping doesn't abrade the nickel matrix holding the diamond in and remove it. On very fine diamond stones if you try to lap a waterstone you will destroy the diamond plate in short order. For this reason I also always lap my stones with the diamond stone on top and under running water, so the "mud" gets rapidly washed away.

The same thing happens when you dress a grinding wheel in a machine shop with a diamond dresser. If the diamond is traversed too slowly across the wheel (this would be like a fine diamond lapping plate for comparison's sake) you get a very fine finish with the wheel but it takes forever to remove any metal and burns the surface easily because there's a LOT of heat produced due to high friction. If the diamond is traversed too quickly the wheel really removes material quite amazingly fast, but may leave irregular lines behind in the surface finish. Get the traverse speed (or lapping plate grit) just right and you have a great finish and good material removal rate. I like to use either the XXC or the XC DMT plates on my Shaptons. XXC for resetting bevels, XC for finishing and finer stones. My finest is 15,000.
Click to expand...


Wow eKretz, thank you for that in depth explanation friend. I hadn't really thought about it like that, but what you just said has shown me that I was completely thinking backwards on this. Thats the first time Ive even read an explanation on flattening like that. So, in that case maybe the 320 is even borderline too fine? I don't think i'll be shelling out too much money for lapping plates too soon until I start building up my collection of stones, but I could go to Harbor freight which I hear sell some real cheap lapping diamond plates i think.

Again, thanks for the info guys, and for now Im either going with the 320 grit paper on granite, or seeing about one of those cheap lapping plates.

dave
 
You're welcome. Here's what I'd suggest: Pick up some different grits of abrasive sheet and try them out before you pick up the diamond plate. You may find you like different lapping grits for different purposes like I do. In any case, if you ever do want to use a finer diamond plate for lapping your waterstones, use a coarse one first to flatten the stone, then you can just prep the surface with a few swipes from the finer one.

Just as an example: I sharpen and shave with a straight razor, and I used to lap my Shaptons (My coarsest Shapton is 2,000) with only the DMT Coarse, and it would take me forEVER to set the bevels and grind out the DMT Coarse marks from initial bevel setting. Once I got to thinking about it in machine-shop grinding wheel terms, I picked up an XXC and an XC to lap with and now it's down to 15 minutes for a complete bevel reset on an eBay razor. I lap with a few swipes of the DMT Coarse on the 15k Shapton only for the final few honing strokes and then strop.
 
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