Hi
Quick update,
I returned the stone and got a replacement no problem (i thought)
So of course wanted to try out the new one straight away.
Using water this time, i proceeded to work on one of the marples chisels i use at work. Nice course grinding for all of about a minute then the cutting sound seemed to fade away :shock:
I cleaned off the stone to find that the diamonds have became a lot smoother.
Turning the stone i tried the fine side, it started to cut more aggressively than the course side was :shock: then it too seemed to become very smooth.
Now i know that diamonds bed in, but this is ridiculous. Surely they should cut much faster than an oilstone (which i normally use).
When i dry it off with a cloth i can hear the abrasive , but to the touch it feels very smooth on both sides, and it takes an age to get an edge of any sort.
I am not a happy camper :evil:
Trend have definitely gone way way down in my book :x
Cheers,
Gary.
OK, what you're seeing is a matter of poor grading and monocrystalline diamonds (which at least a short while ago were the cheapest type - either type works fine, though -that's a discussion for another time).
What happens with electroplate hones is that the large diamonds in the group stick up and they don't wear off, they get pulled off. This is true for DMT and not just trend.
As far as I know, trend is a chinese-made hone and other than being slightly flatter than the $25 8x3 milled diamond hones on ebay, I'm not sure what advantage it might have as I'm using a chinese-made hone that's several years old.
No worries on your first one. WD-40 is no threat to electroplate - trend pushes their honing fluid - my opinion - because they want to take something cheap ( a mixture of mineral spirits and naptha) and make a gigantic margin on it. Sort of like their plates. If a plate loses a section of plate without having something that reacts with the plate itself, then it's defective.
Diamonds bedding in is a matter of what occurs when you use plain cast iron, they stick in the softer surface and skid across the harder (your tools), but they sit on nickel electroplate and don't dig in - the slowing down is them coming off. That will continue to occur over time and the diamond hone will become slower than an equivalent waterstone (like a shapton 1k). I you want to use one long term, the trick is to get one that's more coarse than you think you want (e.g., if you want something like a 1200 stone, then an ezelap 600 is a good place to start. It'll be like a 300 stone when you first get it, but settle in to much finer pretty quickly).
For most tools, a slurried oilstone will cut faster than a diamond stone, and something like a fine india much faster. Only when you get to really high hardness or a complex alloy will that change and the reality is that in the cycle of actual use, the complex alloys just aren't that much better (often worse).