Let me throw out a few things…
I guess we should say what pastes and what sprays we are tallking abut before comparing them.
In general the sprays from HA or Ken Schwartz have a higer concentration of diamond in them than the WEPS pastes. There are othe pastes around. I have been using DMT pastes and bought some on Ebya too. I don’t think, from my results, that any of them have as high a dimond concenatration as the sprays mentioned above (I have seen no published specs for concentration on any of them). This means that you get faster results and potentially more micro scratches when using the sprays. Maybe this is why Mark said:
” If you still want to have maximal abrasive power, go for the sprays. If you want a smooth finish and a mirror edge, go for the pastes. “
Now I said maybe more micro scratches with the sprays. I meant that you need a micro scope to see them.
Visually you will get every bit as much a mirror vevel and edge refinement with the sprays as with the pastes. I say this having used both on lots of different blades!
Even with the 400X Veho, the sort of scratches caused by the 1 and 0.5 micron sprays will be at or below the resolution limts of the camera. In other words the smoothness of the finish will be indistinguishable visually, but you will get where you want to be considerably faster with the sprays.
Geocyclist asked about the carrier. I have both oil based and water based sprays. I am pretty sure that HA has a detergent in water for the carrier, Ken uses distilled water (IIRC), a few other brands that I bought use a light oil. In all cases the carrier either evaporates or if oil is absorbed into the leather. This leaves primarily the abrasive on the surface.
Sprays make it much easier to get a good thin even coat of abrasive on the media. There is not as much guessing or diluting paste and redistributing it. You can see what you have on the substrate and easily add where you need to.
I find that an application of the spray lasts pretty close to the same number of blades as does the paste. This is going by memory, as I don’t document this. I just recharge when it feels right! 🙂
Of course the sprays are typically more expensive, but you get quite a few more applications from the 2 oz bottle of spray than the syringes. Just guess here, but my gut tells me that the cost per application is pretty close, but in the long run the sprays are cheaper to use. I have had 2 oz bottles of the 1 and 0.5 micron HA spray for a couple of years, 40% left, and I have done a bunch of knives. I have also used the same two bottles to coat a couple of 3″ by 12″ bench strops, more than once. I went through my first two syringes of the WEPS paste (5/3.5) in about 6 months. Yes I put way too much on the first time. I am sure it would last longer if I knew then what I know now.
I use the pastes down to the 3 or 3.5 micron level and the sprays below that.
I have some Ken Schwartz 1, 0.5 and 0.1 micron CBN paste. I got it for the leather belts on my belt grinder. At one point I tried it on leather WEPS strops. I was not that thrilled with the mess , nor did I like the results as much as with the sprays. It, even though maybe a bit thinner than the WEPS pastes, was a pain to apply evenly. Granted, Ken said he formulated these for belts and has material in them to help condition the leather in that application. But I just had to try them with the WEPS.
If you want to go finer than the 0.5 micron level, I have not seen any pastes that fine (other than that one from Ken I metioned above at 0.1, but not meant for what we are doing with the WEPS), you need to go to sprays. I have the sprays down to 0.025 microns. I told Ken when I bought them that I really doubted I would be doing anything but wasting time at that grit level (but I just had to know:)). Well with the 0.025 on nanocloth, and whisper light strokes, it usually makes the difference in passing the HHT.
So…
Bottom line, my recommendation is to buy the sprays at the 1 and 0.5 levels rather than the paste.
Phil
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