Precision Ground Toolroom Stones

Bob, I picked up a set of stones made by GWHOLE, made in China. I was quite impressed on how flat they are right out the box. Not sure about the quality of the stone. When I rub them together, they seem to wear down producing powdery superfine grit. I also have a set of Norton stones as Robin uses in his video coming sometime next week. When I get them, I'll see how flat they are coming out of the box. Then I'll set up and SG all four stones and report my results. Ken
 
4gsr said:
Bob, I picked up a set of stones made by GWHOLE, made in China. I was quite impressed on how flat they are right out the box. Not sure about the quality of the stone. When I rub them together, they seem to wear down producing powdery superfine grit. I also have a set of Norton stones as Robin uses in his video coming sometime next week. When I get them, I'll see how flat they are coming out of the box. Then I'll set up and SG all four stones and report my results. Ken
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Thanks, Ken. I will be trying it, too. I do not have flood coolant on my surface grinder and I wonder how the diamond grit in the resin bond will do against the stones. I do have a mister setup I could use, or perhaps a plastic pump bottle like for various household cleaners. It might be good to find a pump bottle that can send a real stream, I will look around in my stuff for one. We want to flatten the grains, not tear them out. Heat could cause problems with the grit coming apart from the bond, or with damaging the resin bond on the wheel. Wisdom?
 
I have a flood coolant system set up but haven't used it yet. I've been dry grinding since day one. The only real problem I see using dry grinding on these stones is the dust it will create. A mister I think will be your best bet keeping the dust down. I think from our standpoint, we will see very little difference between dry and wet grinding of stones. As for clogging up the diamond grinding wheel, I don't think that will be a problem. I don't think using a mister will clog up the grinding wheel either. Should help keep it from clogging up. Ken
 
As much as I have used diamond wheels to grind carbide, I've never had a problem with the wheel clogging up on a 150 or 220 grit wheel. Now, the 800 grit wheel I have on the old slow speed grinder for sharpening my scrapers, it seems to load up a little, but a wipe from a rag when it's not running usually all it needs to remove spent grit. Now, the few Chinese diamond wheels I've bought, I have mixed results in using them. They don't seem to cut as good as a good old Norton diamond wheel will. Just my opinion!
 
I loved the video and ordered an offshore diamond wheel and 2 - 4" X 1" stones to try out. I intend to dry grind the stones and see what happens. They say that I'll get them some time mid-to-late Jul. Fingers crossed!
 
Dabbler said:
I loved the video and ordered an offshore diamond wheel and 2 - 4" X 1" stones to try out. I intend to dry grind the stones and see what happens. They say that I'll get them some time mid-to-late Jul. Fingers crossed!
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Let's all keep in the loop on this. I have the diamond wheel and the stones, but it has been blazing hot here (108 F forecast today, 110 F tomorrow) and I have some other things I need to get done as well. I am quite interested if dry grinding will work for this. My plan at this point is to use my mister unit. I wonder if cutting oil or shortening might work?
 
Bob Korves said:
.......... I wonder if cutting oil or shortening might work?
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I don't think you want to try that on a diamond wheel.

Just as hot here if you figure in the humidity, just have too many irons in the fire here to play right now. Maybe this weekend before I can play.
 
My friend Bert only dry grinds with his diamond wheels. I know about toxicity of carbide, etc, but from the wheel longevity of the grinding wheel, his have lasted 30 years.
 
Dabbler said:
My friend Bert only dry grinds with his diamond wheels. I know about toxicity of carbide, etc, but from the wheel longevity of the grinding wheel, his have lasted 30 years.
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Thanks, Dabbler. I am not in my comfort zone with these resin bond wheels. I have a 4" cup wheel with resin bond diamonds, 600 grit, and it works good dry, but I only use it at very slow RPM for sharpening carbide scraper blades. Robin was taking some eye opening plunge cuts in his video, and I don't think I am ready for any of that yet, don't want to destroy the wheel or throw a stone. Speaking of which, are there other work holding ideas beyond the feather board tools Robin was using? Is just blocking them in well with steel near the stone thickness good enough?
 
Bob Korves said:
Thanks, Dabbler. I am not in my comfort zone with these resin bond wheels. I have a 4" cup wheel with resin bond diamonds, 600 grit, and it works good dry, but I only use it at very slow RPM for sharpening carbide scraper blades. Robin was taking some eye opening plunge cuts in his video, and I don't think I am ready for any of that yet, don't want to destroy the wheel or throw a stone. Speaking of which, are there other work holding ideas beyond the feather board tools Robin was using? Is just blocking them in well with steel near the stone thickness good enough?
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I plan to make a steel fixture for grinding my 4 X 1 stones, consisting of a channel that is wide enough for the stones plus 2 layers of notepad cardboard. There will be set screws along one side to put even force on the stone and a plate at the end for support. I'll pregrind the bottom so the stone will be held flat (or on 3 points as necessary). When I'm done the jig I'll post a photo or 2.

I believe Bert's diamond stones are vitrified bond, I'll check with him on this.

My diamond stones are coming as resin bond (cheap, less than 20$ CDN each). I know that you can't put much pressure or generate much heat or the resin is toast. I'll be plunge cutting as well, but in tenths with very slow hand wheel feeding, and waits at the end of each pass. I won't be using coolant, even though I have the setup. I don't intend to clean up 100% of the faces, so if there's a little around the edge not flat, NBD. I want to get to the end result for this test with as little fuss as possible.... About the jig - for a very experienced grinder hand, I'm sure the finger boards are very safe. I'm absolute novice to SG, and rely on Bert for my info. For this test I'm much more comfortable making the jig. Maybe one day I'll make finger boards and try it. -- When I've got a lot more miles on the grinder.

I worry if the parts are just blocked in, then there is too little pressure on the stone to keep it from vibrating and moving. just my $.02.
 
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