My inexpensive diamond plate arrived...

Re: My inexpensive diamond plate arrived...

John K Jordan

>>>The chisel had been poorly ground, so I reshaped it a bit on the grinder on the new to me CBN wheel and then finished it up on the plate.

You probably do this already: wear protective mask or respirator when grinding on a CBN wheel. Extremely fine still "dust" floats through the air which is probably not good to breathe. I discovered steel dust covering some magnets high on the back of my bandsaw over 10' from my sharpening station.

JKJ

Re: My inexpensive diamond plate arrived...

Barry Irby

Thanks, I knew that but in the heat of the moment I forgot. It may have been good that I was directly under my Ambient Air Cleaner. I think I will put some magnets on the chute and near the wheel.

Wonder if a wad of iron filings stuck to a magnet on the chute is a fire hazard?

Re: My inexpensive diamond plate arrived...

Ray Mtn. Home Ar.

When I have been doing some really heavy surface grinding work I Have had the buildup on the guard light off. It glows a really bright red.

Re: My inexpensive diamond plate arrived...

John K Jordan

>>>Wonder if a wad of iron filings stuck to a magnet on the chute is a fire hazard?

Yes. Here is my experience.

I have a strong magnet under and slightly to the side of a CBN wheel and it gradually built up a fuzzy puff ball of fine steel dust over an inch in diameter since I failed to clean it regularly. Note that this is a 600 grit CBN wheel which I use only to remove extremely small amounts of steel when sharpening lathe tools - it's never used for shaping a tool. I sometimes see very faint and short length sparks from the tool.

One day as I walked away I looked down and saw a red glow deep inside the puff ball. A spark had set it on fire and the center was a small glob of molten steel. If you've ever burned fine steel wool you know how easily it ignites. (Sprinkle a little aluminum powder on the steel wool first and watch out!)

I was able to scoop up the magnet and carry it outside and put out the fire. Who knows what may have happened if I hadn't noticed it until too late.

I keep the magnet but now clean and check it regularly. Some people put the magnet inside a plastic bag so it is easy to clean. Or use no magnet and clean the area frequently.

JKJ

Let me tell you my experience..

David Weaver

- 2 atomas (great, generally a $55 or so item in japan - you do at least get what you pay for)

- 2 eze lap one sided 8x3 plates (they used to be $35 each on amazon, also great)

- 2 dmt duosharps -OK, wouldn't buy again though at what they cost most places

- 2 chinese plates from best sharpening supplies or some site like that - milled steel and two sided. They were about $50 each, and to my eye, look like a $25 chinese plate rebranded (probably much less than that bought in volume and shipped surface)

* two "DMD" branded chinese plates much like the two mentioned above. $25 each shipped from china, two sided and both came with a heavy rubber adjustable base like the steelex base that costs as much as the chinese stones

With minor differences and perhaps some slight lack of flatness in some of the above, all are similar durability. They all slow down drastically early on and then settle in and work pretty much forever at a slow pace unless there's plating loss.

If I were starting over now, with as much as I sharpen thing (and make tools). I'd have one atoma and two of the chinese 8x3 stones that were $25. If I used mostly power tools, I'd have just one of the chinese stones.

When the trend stones came out, they were tried for a few rounds on the razor boards. Their flatness spec makes no sense (it's flatness per inch), and some of the razor users complained about lack of flatness. These are people who were restoring and selling razors, and I doubt the stones were unusable, but maybe not tolerable for someone trying to minimize time (trying to make money preparing razors or offering honing services) and have the same relative flatness across all stones. Several of those folks sent them back.

Their cost was above DMT and they said "designed in the UK" or something like that (and at that time, were marked made in china).

I'm guessing about the reason for the take-over of the trend stuff everywhere (better for everyone in the supply chain except not better for the buyer - my opinion), but have no hard data - just experience buying plates that are strikingly similar directly from china for almost nothing.

The hone that I use day to day among all of the above if I have a need for a diamond hone is one of the last two (the inexpensive milled steel two sided chinese hones directly from china). The listing where I got them is no longer active, and I'm sure they're a few bucks more now, but probably not much more. No plating loss in either one of them and they have been used at least as heavily as any other diamond hone that I've ever had.

Same dust

David Weaver

The same dust goes everywhere with friable stones, but it's harder to notice because there's so much grit mixed in with the metal dust, and the grit particles are bigger.

I have seen the same thing, but less floating off of my CBN wheels. Without the abrasive shedding everywhere, though, there is fine metal dust probably in a 3 foot radius on the floor under my grinder if I haven't swept in a while.

I'd rely on bill to speculate on unhealthfulness of most common alloys - I remember Larry Williams having some pretty stark advice about health issues with metal dust, but sometimes Larry speculated conclusions (e.g., "chromium is carcinogenic and you're breathing it in if you use steel with chromium in it - that was one of his things. I think if that was a concern the same way hexavalent chromium is, we'd already know about it).

Moving to a CBN wheel does quickly illustrate how much metal we're actually grinding everywhere once the gritty abrasive particles aren't mixed in the swarf.

Re: My inexpensive diamond plate arrived...

David Weaver

See if the filing pile ever becomes bright orange. When I make tools, there's usually a fair bit of grinding to set bevels, etc, or shape. The spark from hardened tools is pretty good at accumulating and making the cake under the wheel glow. If I've done anything else, like trim a dowel to a point, then I can smell the dust burning when it burns out of the glowing sparky cake. Not sure I'd want to vaccuum that and have it going through a dust collection system.

blacksmithing and grinding

David Weaver

I've started to take some interest in blacksmithing and grinding (not much grinding and abrasive finishing, but a little bit).

It does look like metals high in chromium that are sparked can be harmful in terms of respiration.

Any heating (data in the metal industry for tradesmen employed as casters /melters) and grinding. But the data are for full-time employees and the case studies that I saw are in Malaysia.

That said, even basic exposure to continuous dust can cause pneumoconiosis for grinders and deburrers.

Long story short, I have no clue if what we do as hobbyists has much potential impact, but if there's any question, it looks like the same considerations as wood dust may apply.

In the studies, smokers had more health complications than non-smokers when combining the smoking with dust inhalation.