The first thing we should do is to define just what we hope to achieve. In principle, polishing is the removal of all marks and scratches, leaving a fine surface free from blemishes. In practice we will never fully achieve this. Instead, one can only remove deep marks by carefully rubbing; substituting in their stead a series of finer scratches. The finest abrasive made will still leave a series of marks. However, once these marks become microscopic, we can consider that we have achieved a fine polish.
The ‘trick of the trade’ then, is to work on a surface with a particular grade of abrasive until all previous marks have been removed. Only then should one change the grade of abrasive to a finer one.
For this reason we would suggest that you commence with a coarse abrasive cloth – preferably an abrasive cloth of about 120 grit. The cloth can be purchased in sheets roughly A4 in size. Ask for emery cloth in grades of 120, 240, 400 and 600 grit. One sheet of each size grit will give you sufficient abrasive to polish a number of knives.
There are a number of polishing techniques. Probably the easiest one is to tear off a strip about 50mm wide. This should be wrapped around a solid object such as a piece of wood or metal. Now, you could wrap the cloth around a file, after all, you will have a number of them on hand. However this is not a good idea, for one basic reason. You will find that after a while the cloth tends to wear through. If the cloth is wound around a file, the file will then scratch the metal surface. This will negate all your previous work. It is for this reason that we suggest you seek an alternative base for the cloth.
Mount your knife blank back on the wooden support. Start with the 120 grit and polish just one surface – be it the flat of the blade, or the filed facet. The cloth should be kept moist with a lubricant. You can use ordinary mineral oil (car oil), kero, a mixture of both or neatsfoot oil. Neatsfoot oil is an animal oil used for dressing leather. For some reason it seems to work better than any other lubricant we have found to date. However, if you want to save money, use car oil. (the one lubricant that won’t work is ordinary water. This dissolves the glue and the grit comes off the backing cloth).
Moisten the cloth, and polish the one surface until the cloth is worn out. Tear off the worn out piece and expose a fresh surface. If you have removed all previous scratches, move to another surface. If you haven’t continue polishing the surface you are working on.
You should have a piece of cotton cloth on hand. You can use this to wipe down the polishing area, and observe your results. The job is messy as the polishing creates a black/grey coloured paste. This will wash off your hands quite easily so don’t worry.
Keep the oil on your emery cloth, and keep polishing until you wear out each fresh cloth surface. Try to polish in just one direction, i.e. lengthways or across. It is not advisable to start changing directions, as you will find the scratches left are hard to remove.
Also, try to keep your polishing as flat as possible. Unless a surface is supposed to be curved, try to keep it flat.
Try to cover the longest possible area with each polishing stroke. If you are polishing the flat of the blade, try to cover the full length at each stroke. This really takes no longer and effectually increased your polishing speed. Again, a machine-like rhythm to you polishing. It makes the job easier.
When polishing flats of the blades, make sure you polish back to the area that will be covered by the plates. When the knife is assembled, you want an even polish right back to the handle. The extra few centimetres of polishing add nothing to the work, but make all the difference to the job.
Only when you are satisfied with your polishing in one grade, should you change to a finer grade. Make sure you remove all of the paste from the previous polishing, and work on a clean surface. The paste from the previous abrasive cloth will contain most of the grit. These would continue to mark the surface, whereas you are trying to remove these scratches with finer ones.
As you progress through the finer grades of cloth, you may give less time to polishing with each grade. If you are thinking you are getting a fine polish, look at the surface in bright sunlight. Hold the blade so that the light is at an angle to the blade. This will soon show what marks re left on the surface. While it really doesn’t make a lot of difference to the use of the knife, it does show the difference between a well-done job, and a half-done job. It is up to you as to how long you continue to polish.
When you are working in fine grades, you will find that the cloth soon clogs wit metal. This will be despite the use of an oil. This clogging does not necessarily interfere with the cutting action of the cloth. For really fine work, it pays to continue using the cloth, even after it is clogged. At this stage you will be making a burnished finish, rather than an abraded finish.
If you really want to gain a glass like finish, you can deliberately burnish the steel. To do the, you would need to make a burnisher.
A burnisher can be made by grinding all the teeth off a round or rat-tail file. The easiest way to do this is using an emery wheel. Rotate the file while you grind, and try and get as fine a finish as possible.
Polish the file with emery cloth, the same way you’ve been polishing the blade. When you have achieved a polished surface, have the file buffed. The easiest way to do this is to take the file to someone who has a buffing machine – say a local gun shop. Ask them to buff the surface to the best finish they can manage. This shouldn’t cost more than a couple of dollars. Most gun shops won’t have heard about burnishing, so take no notice of their comments – we are telling you how to achieve the ultimate hand finish.
To use a burnisher, you will need to have a perfectly clean job. Wash all traces of grit off the job. Soap and water or kero will do this. When the job is clean (and dry) , mount it back on a clean backing board. Lightly smear the surface with oil. Using a heavy stroke, move the burnisher in one direction, along the length of the surface to be polished. Lift off at the end of the stroke, and repeat the operation. Ten strokes of so should be all that is needed on any surface.
Burnishing works by pushing the metal around. It closes over the scratches and pores in the metal. It only works successfully on metal that has already received a fine polish, and is one of those processes that should only be used on a really worthwhile knife. Ordinary knives are hardly worth the extra effort – unless you want to master the process, which then makes any process worthwhile.
To polish the brass, the same steps as used on the blade are necessary. You will find that brass polishes easily so it won’t take long. While you can burnish brass, you can finish the polish with a piece of hessian bag or canvas. This will be sufficiently abrasive to give an ultimate finish.
