DiaSpray Diamond Suspension - Canadian Woodworking Magazine

An easy alternative for putting a mirror finish on blades.


DiaSpray Diamond Suspension

If you're looking for the ultimate sharp edge, you might want to give DMT's DiaSpray Diamond Suspension a try. DiaSpray is a sprayable suspension of .5 micron monocrystalline diamond grit. That's equivalent to 30,000 grit – almost 4 times finer than a 8,000 grit waterstone.

The spray comes in a .85 ounce bottle, and you can apply it to a wide range of backings, including leather, thin cardboard, denim, MDF, and balsa wood. You spray a couple of squirts on the backing, and then strop your tool away from the cutting edge. Of course, you do need to use the DiaSpray as the last step in your sharpening process.

Bevel honed on 9 micron Dia-Sharp stone

I tried the DiaSpray on several knives and a couple of chisels. First I honed the blades on an extra fine (9 micron) Dia-Sharp benchstone – the finest stone that I have. After this I usually strop the blade on a piece of leather using the Veritas Honing Compound, which Lee Valley claims leaves an 'average' scratch size of .5 micron.

Bevel stropped with the DiaSpray

Before using the DiaSpray, DMT recommends that you shake the bottle to disperse the diamond grit suspension. After shaking I sprayed a couple of squirts onto a piece of plywood. In the photo above the bevel was stroked a couple of dozen times.

Back of the blade stropped with DiaSpray

I also used the DiaSpray on the back of a couple of chisels.

Overall, the finish I achieved with the DiaSpray was excellent. 
A little goes a long way with the DiaSpray, which is good, as the bottle only contains .85 ounces. It's also pretty easy to use, just shake, squirt, and stroke.

Visually I found it difficult to tell much of a difference between the finish I achieved with the DiaSpray and the Veritas Honing Compound. If you hone your blades well, then both stropping compounds will produce a mirror finish - at least to my eyes.

I encountered one problem with the DiaSpray bottle. After seven or eight uses, the pump mechanism malfunctioned - the diamond suspension appears to have clogged up the pump. Fortunately I had another small, empty spray bottle on hand, to which I could transfer the contents.

If you're not satisfied with the finish you currently achieve in your sharpening regime, and you don't have a honing compound, then you might want to give the DiaSpray a try.


The folks at DMT have only heard from one other person experiencing the problem with the pump mechanism on the spray bottle. Stan Watson, DMT Technical Director, has not personally encountered this problem despite using the DiaSpray often. He recommends that, if someone encounters this problem, they should lift the spray nozzle off of the bottle and run it under hot water for a few seconds. That should clear any "clog."

I tried this on the original spraynozzle and it did, indeed, clear up the problem. Our thanks to DMT for clarifying this issue for us.


  • .5 micron monocrystalline diamond suspension
  • .85 ounces
  • Usable on leather, thin cardboard, denim, MDF, balsa wood

SOURCE:How To Purchase
May 2014

Carl Duguay
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