top menu
     

Honing Straight Razors with Lapping Film

film hone overview

One of the major expenses of using straight razors is the fine grit hones required for edge maintenance. Standard stones are far too coarse to be used with razors, razors require very fine grits, usually starting at $80 for an artificial waterstone and the sky is the limit with natural stones dug from rare deposits. Using lapping film will allow you to hone a straight razor for a initial investment of about $40 and give you a larger range of grits to work with than a single two sided stone.

I am not going into the nuances and techniques of honing itself in this article. Once you get set up correctly, it’s just like using a stone. Once you’ve got your honing film set up, see one of the many fine tutorial videos available on the web.

Honing with lapping film is a bit controversial. When I looked into it, I found many people hated it and every once in a while somebody had really good results. The cost was low, so I gave it a try and worked through some problems until I picked up the techniques in this article. Honing film works very well when used properly.

Using honing film

Supplies needed:
• Granite or marble tile. Minimum of 3”x8” recommended. One advantage of using film is you can set yourself up with a large area to work with. Most tiles will be larger square tiles anyway. Check top surface and make sure it’s perfectly smooth and flat, and find one with minimal edge chips. Cost is typically around $2. The tile must be slightly beveled on the working edge. Ceramic tiles will generally not be flat enough for this purpose.
• Non-adhesive lapping film. I recommend getting a few sheets each of 3 micron and 5 micron, these are your workhorses. You will also need a couple sheets of 1 micron to start with and maybe a sheet of coarse film like 12 micron if you need it (more on this below in the notes).
• Spray bottle with water.
• Clean lint free rags and an old gift card.

edge of lapping plate
Lapping plate edge must be beveled or rounded.

Procedure to use lapping film for honing

First step is to set up your lapping plate, ie the tile. I like to put in on something to lift it up an inch from the table and give myself a little knuckle room. You can glue it to some scrap wood for a permanent solution. Check the working edge of the lapping plate to be sure the it is beveled and smooth.

Wipe the lapping plate with a clean cloth to remove any dust and hairs. Then lightly mist it with water. You will only end up with about 2 drops of water trapped between the plate and film, so you do not need much water at all.

film on plate
Ready to squeegee out air and excess water.

Now take the piece of film and wipe both sides with a clean cloth to remove dust and hairs. Apply it to the surface of the lapping plate. Position the film so it hangs off the working side of the plate a little bit, a millimeter or two.

Then use the gift card to squeegee the water and bubbles out from under the film. Use light pressure and remove all air bubbles and as much water as possible. Use a cloth to wipe up the excess water at the edges so it is not drawn back under the film. In this state, the film will be completely immobile for normal razor honing.

ready to hone
Ready to use. Note how film overlaps the beveled edge.

You can then put a squirt of water on the top of the film and lightly draw your razor across and feel for bumps or roughness. This is dirt or hair on top of or below the film. If you feel anything, clean the top of the film and try again. If you still feel it, remove the film and clean underneath, then reapply.

If the surface is smooth and you don’t see any bubbles under the film, you can proceed to hone. I’ve made the process sound complicated, but it really only takes about 30 seconds to apply a film.

Here is an example progression I would use for a razor that had minor edge issues, but no naked-eye visible chips. The 5 micron would not be needed for a light refresh hone on a clean edge. The following is based on inspecting the edge with a 15x loupe.
• 5 micron lapping film until all edge imperfections removed
• 3 micron lapping film until all scratches from 5 mic removed
• 1 micron lapping film until mirror finish
• Chrome oxide on balsa 20 laps
• Leather strop 50 laps then test

lapping film

Where can I get lapping film?
Non-adhesive lapping film is used mainly to prep fiber optics for data transmission. It is also used to hone wood tools. Sometimes you can find a cheap source in the razor forum classifieds. If not, search fiber optics supplies and check your options. I have purchased from both the forums and from fiberoptics4sale.com. Both were acceptable. Lapping film comes in silicon carbide, aluminum oxide and diamond. All will work fine, my preference if for aluminum oxide, if available. It’s a little less scratchy and a little faster to final polish. If you have large pieces of lapping film, cut them down to an appropriate size. I like pieces about 3 inches wide and 9-10 inches long.

Notes:
Do not throw away worn film. Lapping film will lose the majority of it’s abrasives over the course of several razors, but it is still very useful. A worn piece of film loses one or two microns of grit, but becomes smoother. A worn piece of 5 micron is between a lot like 3 micron. A worn piece of three micron is similar to a piece of one micron. In fact, I prefer a worn piece of 3 micron over a new piece of 1 micron. The surface is smoother and has a better feel, but still cuts fast.

A small amount of detergent can be used in the water, if you prefer. But I find it wears the abrasives off faster than plain water. I just clean my film with rubbing alcohol if it gets loaded with swarf.

Coarse films are generally not worth it. They perform like 1000-1500 grit wet dry sandpaper, which is widely available. Also 1000-1200 grit waterstones are not that expensive or hard to find and can also be used with your kitchen knives. You only need these coarser grits if you are fixing significant chips or reshaping a blade.

View More Razor Articles Here

 

           
   
      All content ©2008-2013. All rights reserved.