Abrasive Personalities, Part Deux

Honing film is the least expensive way to get started with a sharpening system. For very few dollars you can have an enormous range of grit sizes, a flat thing or two to stick the film to (glass, granite, etc.) and you’re ready to sharpen all the way to 0.3µ (that’s the Greek letter “mu” that stands for micron, one of which is one millionth of a meter) if you so desire. (By the way, that’s a very small particle. We’re talking 0.0000118” which translates to the size of the scratch that particle makes on the steel. Most bacteria are measured in the one to ten micron range.) The grain size on honing film is more uniform than it is in most other abrasive applications. 3M claims that 90% of the grit on their honing film is the same size. In the world of abrasives, that’s a very high degree of uniformity. The grit is aluminum oxide, which is much tougher and lasts much longer than the silicon carbide used on the black wet-or-dry sandpaper sheets.

Coated Abrasives

Coated Abrasives

The “film” of honing film is Mylar – tough and waterproof. Though I use the films dry some like to spray a bit of slightly soapy water on the surface to help prevent clogging or glazing of the surface. I buy honing film with the pressure sensitive adhesive (PSA) backing because, while I am a bit lazy, I find the factory applies stickum in a more uniform layer than the one I try to spray on myself (and I do get it on myself sometimes.)  The PSA sheets that I’ve used have been reluctant to let go, however, and leave behind a mess of glue when removed from my glass substrate which then needs to be scraped off; making the removed film non-reusable. If someone knows a brand or source for PSA-backed honing film that can be removed and reused, please post a comment for us.

My Honing Film Setup

My Basic Honing Film Setup

While a honing film setup may have a low entry fee, the sheets do wear out and after umpteen replacements will end up costing more than a set of stones would have if you had started out with them. But for a low-cost sharpening kit, and to find out which grits you prefer to use before investing in stones, honing film is a great way to go. I have two pieces of ¼” glass the size of the honing film sheets: 80µ on one side, 15µ on the other side of one piece of glass, 5µ and 1µ on the other. With this setup, shown above, and the ruler trick, I can prep one of our Krenov-style blades to shaving sharp in less than a minute. Honest.

About Ron Hock

Owner of HOCK TOOLS (.com) and author of "The Perfect Edge, the Ultimate Guide to Sharpening for Woodworkers"
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10 Responses to Abrasive Personalities, Part Deux

  1. Aric Hartley says:

    I used to use a type of PSA backed sandpaper that didn’t leave a residue behind when used for sanding wood. The brand was Carborundum
    Abresives the premiere red brand but I don’t know if they make superfine grits.

  2. Alexandre Grigoriev says:

    Ron,

    If the film side is glossy (like 3M 5u and 0.5u grits), it sticks to the glass just by itself, though a bit better if some oily residual (mineral spirits wiped off, for example) is present. hicker films with coarser grits are essentially one-two-time use.

  3. Eric says:

    Where is the best place to find the adhesive backed sandpaper, and what grits would you suggest for starting out?

    Thanks,

    Eric

    • Ron Hock says:

      I was hoping some readers would share their shopping tips…

      Honing film is available from most of the online suppliers. I’ve seen it in the offerings of Toolsforworkingwood.com, leevalley.com, woodcraft.com, japanwoodworker.com — I’m sure there are more. Check with your favorite vendor.

      I use 50µ and 15µ on one piece of glass with 5µ and 1µ on another. The 1µ is probably excessively fine but I like to feel that I’ve done all I can. Your mileage may vary and you may find the jumps between grits too extreme. But they work quickly for me and last a long time.

  4. Eric says:

    Thanks. I had been using a course diamond stone, followed by inexpensive stones (800, 1200, 4000 and 8000) on my inexpensive plane irons, but found that when I went to sharpen my new Lie-Nielsen blade, the stones did not do as well as the wet/dry sandpaper I picked up at Walmart (800g, 1000, and 2000g) and a piece of plate glass, so I am now considering sticking with the sandpaper on glass method.

    By the way, I am really looking forward to your book, I have it ordered (amazon.com) and I really wish it would ship before Jan.

    Thanks,

    Eric

  5. Adrian says:

    What 3M product exactly are you talking about when you say it’s a honing film that is aluminum oxide and in the book you said it was closed coat. I looked around for aluminum oxide honing film and basically nobody is selling such a thing, that I can find. It’s all SiC. (Tools for working wood has the aluminum oxide but only at the two very finest grits. They claim that these papers were specifically selected to work the best.) If I knew exactly what I was looking for (e.g. a product name and number) I might have more luck tracking it down.

  6. Adrian says:

    I asked Tools for Working wood why they prefer the SiC paper. Joel told me that they consulted at length with 3M and that the SiC paper cuts much faster than the aluminum oxide paper. He said that the life of the SiC paper (before the particles fragment and the effective grit size falls) is long enough that it makes more sense to use SiC. I wonder if the preference for the Aluminum oxide could depend on whether you’re using powered sharpening equipment, as this might make speed of cutting less important but longevity of the paper more important.

  7. Mark says:

    When it comes to MX laminated abrasives, MX mounted wheels are available in the traditional “A”, “B”, and “W” shapes as well as special shapes. MX laminated abrasives generate excellent surface finishes while simultaneously removing substantial amounts of material quickly. When greater material removal rates are the main priority, CXI and CXN bonds are the best candidate. When formability of the mounted wheel to the work piece is the main priority, CXG and CXH bonds are the best candidate. Abrasives

  8. A very good post concerning work with abrasives, today it is rare to find texts like this.

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