3M Microfinishing Film for tool sharpening

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Review by Purrmaster posted 09-20-2012 06:33 AM 9930 views 4 times favorited 7 comments Add to Favorites Watch
3M Microfinishing Film for tool sharpening No-picture-s No-picture-s Click the pictures to enlarge them

I bought this stuff from Tools for Working Wood a couple of months ago and have been using it since:

This finishing film from 3M is used in place of sandpaper for Scary Sharp. The grit of these are measured in microns. Tools for Working Wood has an article that gives a rough equivalency to the water stone grits. I.e. 1 micron is equivalent to a 1,000 grit stone. Please see:

I really like this stuff for scary sharp. For one thing, you can put a very fine edge on a tool with this stuff. Though I suspect going down to 0.3 microns may be overkill (I do it anyway). It lasts longer than regular wet or dry sandpaper. The adhesive is also reusable. Spray some water onto your sharpening surface before putting down the film. It will stick nicely and you’ll be able to remove it later. I think I’ve gotten the adhesive to last for 4 or 5 stickings and pulling up before it wears out.

The film is also fairly stiff for something so delicate, which is helpful. It stays in place and doesn’t flex. You can put it back onto the backing it came on to peel it off for next time.

From my experience I think it does cut faster than regular silicon carbide sandpaper, though not enormously so. It does seem to take less strokes on this stuff.

It does last a fairly long time, Longer than standard sandpaper. Eventually it will clog with metal particles and have to be discarded.

As I said, I really like this stuff. It isn’t perfect though. It can tear fairly easily, especially on the lower 3 grits. Sharpening only by pulling the tool (not the usual forward and backward pattern) helps. It also is much too delicate for power sharpening. I put some on the glass wheel of my Work Sharp 3000. The film abraded away to the glass in a matter of seconds. I suspect part of the reason for that is that I was using it dry. It’s really meant to have a lubricant. In other words, you must use it wet.

If you use scary sharp I think it’s worth picking up on one sheet assortments and trying it out.

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7 comments so far

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#1 posted 09-20-2012 01:15 PM

I am currently using sandpaper for sharpening, and I found this review is very helpful. Thanks. For the review.

-- "I am a firm believer in the people. If given the truth, they can be depended upon to meet any national crisis. The point is to bring them the real facts." - Abraham Lincoln

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#2 posted 09-20-2012 01:48 PM

This stuff is pretty good. I started using it myself a couple months ago. I had about 11 chisels that needed sharpening, and one 2.5×8” strip of the 15 micron worked well at re-establishing the edge. Then I used the 3 micron, then I used some green compound on a strop. The results were beautiful. This is what is sold as the Pinnacle honing film at Woodcraft, though Lee Valley and TFWW sell it cheaper by the full sheet. Also, at Lee Valley you can get it without the PSA backing. Great stuff, for sure.

-- Brian T. - Exact science is not an exact science

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#3 posted 09-20-2012 08:49 PM

I have used the same film for a couple years now. I agree that the finer sheets can tear so its best do only apply pressure on the pull stroke.

-- Dan - "Collector of Hand Planes"

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915 posts in 2861 days

#4 posted 09-21-2012 12:30 AM

When using the PSA sandpaper from Klingspor I can’t typically get the stuff off the glass without destroying it. With this stuff I can. It makes it more reusable. Just keep it nice and wet.

I do wonder if there is a way to make this stuff work for a Work Sharp. Some kind of backer or a thicker sheet…

Of course scary sharp is not what it was designed for. I think it’s designed for very fine polishing of metals and the like.

Please bear in mind that I really like 3M products so I might have a slight bias in favor.

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1057 posts in 3044 days

#5 posted 09-21-2012 02:27 PM

Good review. Hope you have fun using your new tools!

View Viktor's profile


467 posts in 4187 days

#6 posted 09-21-2012 03:37 PM

I use the same or very similar film and also happy with it. I do not, however, peel if off after use and leave it attached to a granit tile until it wears out.

View G5Flyr's profile


61 posts in 2501 days

#7 posted 08-19-2014 02:48 PM

Good review. Thanks for posting. I’ve purchased these films from TFWW also. However, I’ve only used the PSA backed version. Purrmaster is spot on re cutting faster but applying pressure on the pull stroke only. Per TFWW’s Joel Moskowitz – using a lubricant (water or oil) will make the films last longer.

As for getting several applications (stickings) from one light coat of spray adhesive I have had similar experiences with the wet/dry papers so it makes sense that the 3M films would perform likewise.

As I stated above I’ve only used the PSA backed version of the 3M films. Like all of the Klingspor PSA products the 3M PSA 15 and 5 micron films can be tough to remove without mineral spirits and a razor. The 1 and .3 micron films don’t do this. Go figure… I think 3M Super 77 or 3M General Purpose 45 spray adhesive is the way to go.

TFWW says the SiC films cut better than the Al Oxide in the coarser grits. Joel and company know their stuff so I have no reason to doubt them.

IMO these 3M films cut better than their wet/dry cousins because they are micron graded. That means that all of the particles on the film are the same size. The particles in wet/dry sheets are graded to different tolerances. European (FEPA) papers (P80, P200, etc) contain particles in a range. For example, P200 is graded at 60 microns +/- 2 microns. American (CAMI) papers are graded by the average size of the particle on the paper. CAMI 220 grit has an AVERAGE particle size of 66 microns but no range tolerance. Source: Metal Clay UK (MCUK) Sorry all I don’t have a link.

For more on sharpening I ref 7Footer’s LJ thread “Honing Your Skills”.

-- G5Flyr

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