Thread: Lee Valley Diamond Lapping Film under microscope

Hi Ilya,

Nice work. Bigger pictures would help.

Have you tried to apply some stain to increase the contrast and allow visualization of the smaller particles? Maybe a darker shade of a water borne woodworking stain?

Cheers,
Rob

Thanks, Rob. Good idea on tinting the paper. The point is that the 0.5 micron is already near the diffraction limit (of the optical microscope). And any particles that are smaller will be blurred blobs that are still about 0.3-0.4 microns.

Fluorescence?

What is 'd' (resolution) for your microscope?
I suggest that phase contrast optics might be a better dry answer, if not darkfield and oil immersion.

Hi Rob. The NA of the 100x objective that I use is 0.95, so the resolution in air is very close to wavelength divided by 2. Since we see the whole visible spectrum, the resolution will be better for blue colours and worth for red. On average just under 0.3 microns. Yes, I am aware of many other techniques for nanometer scale imaging, this was just the quickest I have ready access to, and for my sharpening purposes, I do not need to go to below 1 micron.

I don't know that a scratch of 1 micron can make a difference in the visual appearance of any wood.
Still interesting to see that you do get what you pay for.

The 3M diamond films are widely used for polishing the ends of optical fibre connectors (i.e. glass optical fibre embedded in a ceramic ferrule). For this application particle uniformity is absolutely critical - the finished glass surface must have no visible scratches under 400X magnification. Having used the 3M and several other brands, I can confirm that the particle uniformity on their films is second to none.

Final polishing step (wet) for fibre connectors is usually 0.5 micron diamond, followed by various proprietary silica or cerium oxide emulsions. Don't think we need to go quite that far for woodworking tools......

I've convinced myself that honing with less than 0.5 micron abrasive is the legitimate final step for wood carving tools.
With a mallet, I admit that I never notice at all.
But,
just pushing smaller gouges or a crooked knife doing hand work, the difference in effort is clear.
I can feel it. I can feel the edge "going away" in western red cedar or birch after about 30 minutes steady work.
A few swipes with honing compound and all is sweetness and light again.

I don't know what that is doing but the difference: stop to carve after 1500 grit or add the honing step is really different.

Considering the other end of the (tool) scale for a moment....

I asked one of the axemen at the recent Canberra WWW show "How sharp is sharp?". I would have thought that a cutting edge (axe) subjected to such huge forces wouldn't gain much from being as sharp as a razor blade. Much to my surprise, the guy showed me a 15000 grit stone he uses after every competition log to touch up the cutting edge.....

As a brief aside, I've just made myself a couple of new double-sided honing boards using roo tail leather (as recommended by someone else on here). Can someone confirm the best way to get a suitably thin layer of Veritas green honing compound onto the leather? Google throws up all sorts of suggestions from softening the compound stick using a solvent (?) to warming both the leather and compound with a heat gun before applying. I have a total of 4 surfaces to play with, so is there anything other than the Veritas stuff worth trying on a leather hone (which I mainly use for extending the working life of paring chisels between sharpenings)?

Cheers

I don't use any leather any more because it is soft and will dub the edges.

Friction is your friend. Most honing compounds are suspended in a waxy carrier. Almost all waxes melt below 60C.
Hold the stick in your armpit for 10 minutes. Good enough.
Veritas is horribly greasy, it ought to soften and ruin your roo leather quite quickly.

Thus, the harder and faster that you scribble with the honing compound, the temp goes up with friction and more of it smears on the strop.
An even layer is a Peter Pan myth. Just get the surface coated, any scribbles will do.

Me, I have given over to office file cards and breakfast cereal box card as my strops. Easy to load, cheap and they do not deform with pressure.

Cheers - I'll give that a go. I can warm the leather up with gentle application of the heat gun to help things along. I should add that leather from the tail of a roo is VERY hard; it doesn't deform as much as some other leathers.

Originally Posted by Mr Brush

As a brief aside, I've just made myself a couple of new double-sided honing boards using roo tail leather (as recommended by someone else on here). Can someone confirm the best way to get a suitably thin layer of Veritas green honing compound onto the leather? Google throws up all sorts of suggestions from softening the compound stick using a solvent (?) to warming both the leather and compound with a heat gun before applying. I have a total of 4 surfaces to play with, so is there anything other than the Veritas stuff worth trying on a leather hone (which I mainly use for extending the working life of paring chisels between sharpenings)?

I have a strop made of horse butt leather.
to charge, I just crayon the Lee Valley compound and then use the tool being honed to "spread" it. i figure after the first swipe it will be sufficiently uniformly spread to work.

In my carving beginning, I bought a really nice leather strop on a stick.
Decades later, I was convinced that the wax in the honing compound had softened the leather.
I could watch it deform as an edge passed by.

A strip of cereal box card stuck with masking tape to a cutoff from a polished stone counter top is what I use now.
Office filing cards wrapped around mandrels for crooked knives.
The Stubai carver's adze is a 7/75. A tennis ball is the perfect mandrel.