Polishing and Finishing Aids
For polishing it is recommended to use primarily bristle brushes for most of the removal work and to follow up with a buff where necessary. Feel free to use a lot of compound, it is the compound that does the work, not the buff. Old polishers would have dozens of shaped and turned wooden, leather and even paper shapes and wheels to go on the spindle for different problems.
A paper clip serves very well as a handle for any small part with a hole in it; one threads the paperclip through and then holds it while polishing the small part.
A general rule for dealing with institutions is to make friends as soon as possible with the janitors and security guards as they will have a great deal of control and impact on your life. Among other things one can ask cleaning staff to collect the circular centers of the large “scotch brite”®-like discs that are used in big floor polishing machines. The circular centers are about 4” or 10 cm across and are normally thrown away. If one hardens their centers up with hot glue or epoxy then one has almost free abrasive wheels for satin finishing. They can of course also be used as pads for cleaning metal surfaces for soldering and solder before use.
A very useful tool is a cardboard disc sander. One uses the side or large flap of a fairly rigid corrugated cardboard box. Make sure it has not been bent or creased to damage its rigidity. Make sure one side is smooth. The disc will be placed onto the tapered mandrel of a polishing machine. One begins by measuring the distance from the middle of the tapered mandrel to the closest part of the polishing machine or its hood with dividers. The dividers are closed slightly so that the disc clears all parts of the polishing machine and hood when rotating. Remember that a cardboard disc will tend to ride up the mandrel so give sufficient room for this. One then scribes the appropriate sized circle onto the cardboard making sure that the center hole actually penetrates the cardboard.
The disc is now cut out carefully with an X-acto® knife. Remember that most injuries in art schools are from X-acto® knives and do this carefully. Then one takes a piece of 220 grit emery paper, spreads rubber cement (not white glue-it dries in lumps and ruins the tool) onto the slightly corrugated side of the disc, places it on the back side of the emery paper and turns it with some pressure from the heel of your hand so as to evenly spread the rubber cement on all surfaces to be joined.
The disc is lifted off and fanned over the emery paper so that both surfaces become tacky, dull and mat. The two surfaces are then pressed firmly together and smoothed to effect a good join. One then trims the emery paper flush to the cardboard disc using a knife or scissors. Keep it close to the cardboard. 3M® has a 100 grit aluminum oxide paper that outlasts anything else. I have seen one sheet last through a whole workshop of hammers and chasing tool refinishing.
Wearing safety glasses the disc is now placed onto the mandrel while it is spinning so that it rides up to the third or halfway level on the taper, piercing through the emery paper. Get your hand off and away from the rotating disc quickly as any emery paper sticking out past the cardboard can inflict what might feel like the worlds worst paper cut. One holds the back end of a steel file or another piece of steel onto the edge of disc and paper to trim off any overlap and make the edge safer. The motor is now turned off and the disc removed.
The area around the center hole is now strengthened by melting a hard file-a-wax or other wax around the center. If one quickly places a torch onto it and removes it the wax may melt and run into the cardboard about the center making the hole last longer in use. If using wax make sure it is dry and set before use as otherwise a vertical spray of wax occurs when the disc is turned on. Better than wax is 5 minute epoxy which can make a very permanent strengthening support. If using epoxy let harden before replacing on the mandrel.
With epoxy one can also place a little mesh circle around the center to provide a little more rigidity. When in use there are a number of cutting speeds available depending upon how close one is to the spindle; further out is faster: closer in is slower. Within a very few minutes there are also a number of grits available as the more used parts of the disc become finer so that one has a lot of choices in speed and grit size all on the same tool and accessible with a minimum of hand movement. To stiffen the disc while it is running one can hold a piece of wood behind it on the paper side while it rotates so as to obtain a more rigid surface for faster flatter cutting.
The tool is used to sand flat surfaces onto jewellery replacing much more expensive jewellers laps. It is unsurpassed for reshaping commercial and handmade chasing tools and hammers. One can go directly from this sanded surface to a polishing buff. On steel one uses Fabulustre® on a buff and the process of completely refinishing a hammer can be reduced to five minutes or less.
It is absolutely essential that the air and dust intake on the polishing machine be completely blocked off with a piece of cardboard when using this disc as sparks can be produced which will set the cotton lint and dust in the filters on fire. This is a very real danger of fire with such flying sparks-I’ve seen it happen twice.
If one places a polishing compound such as tripoli or Fabulustre® onto the smooth paper side of the disc then one has an extremely fine polishing lap that can produce superb flat surfaces on jewellery with plane surfaces. If one makes a traditional type disc one can rubber cement a piece of linen writing paper onto the paper side for an even smoother polishing effect. It is far superior in flat finishing to expensive hard felt buffs that jewellers use. Plain paper would probably work well for polishing. Several discs with different starting grits are useful. For a minimum cost and preparation time this type of disc sander and polishing lap offers a great deal.
Some polishers will take a stiff paste of baking soda and water or icing sugar and water and fill up holes for stonesettings and other places they don’t want polishing residues in on a piece of jewellery. When it dries this prevents accumulations of polishing compounds in those places. When the polishing is finished one washes out the water soluble paste and so saves time and effort in cleaning out such places.
When holding a ring onto a felt ring polishing mandrel on the machine it is often useful to have a short piece of a leather belt looped over so as to hold the ring in place on the mandrel while it is polished. The two ends in the hand become a handle. This also protects the fingers from heat while polishing.
A tool can be made from a wooden clothes pin which is hollowed out slightly with a large round burr in the curving hollows already in the jaws. This holds a ring while polishing primarily for the flex shaft but will also work on the large inside ring buff on the polishing machine.
Another version of the same type of tool for holding a ring while polishing is made by taking a lath or similar rectangular cross sectioned piece of wood and cutting a circular hole near the end. The inside of the circle is carved away somewhat with a round burr in a similar manner to the clothespin in the previous description. Then the lath is slit down about two thirds or three quarters of it’s length with a wide sawblade (band saw) and if possible the end of the slit is drilled so as to help prevent the wood splitting in use.
To use it the wood is flexed open slightly, the ring inserted into its rounded groove and the tension of the lath holds the ring tightly for polishing. Some people like this one because when using the flex shaft they can rest one end on their shoulder while they use it.
There are also metal clamping and holding tools designed to hold rings while polishing available from commercial suppliers. These work very well.
Holding items for polishing is an art form to itself. In factories they sometimes cut a hole in a piece of steel sheet which surrounds and supports the part to be polished. The steel sheet with the hole in it is then carefully attached to a wooden dowel of appropriate diameter with countersunk screws. This is then used to hold the production component in place while it is held against the buff. For a single cast production item I have sometimes heated up the piece and working quickly, burnt a hole which fits it into a piece of wood to hold the piece in place while polishing.
Never use gloves while using a polishing machine! I have seen and heard of some pretty nasty accidents from this. You never want to get your hand tangled into an powerful electric motor. Always work with respect for power tools, don’t talk while using them and keep your attention on what you are doing. In a serious accident one’s first thought is often “that was stupid”.
Some people use “alligator skin®” or similar webbing tape combinations to protect their fingers while polishing. Even masking tape has been used. Usually though one uses cut off leather fingers from gloves and uses them.
A German polishers trick is designed to avoid the possibility of being trapped in the buff and still use a cloth pad to keep heat effects down and keep one’s hand cleaner. If one places a strip of sheet about 3 inches wide and 8 inches long when folded tucked under the middle finger and over the ones on each side of it then one can hold items which get hot from polishing without burning one’s fingers.
One uses a leather thumb as well. If the cloth is caught then it is whipped from the fingers onto the wheel without any chance of damaging the hand. Make sure you have it right and try snatching the cloth from your hand suddenly a few times so you understand how it works before you try it with a polishing machine. This is potentially dangerous!
There is an attachment for a standard polishing machine spindle available from companies such as Gesswein which hold a 2mm burr shank, which is the standard size flex shaft tool shank. It is brass in color and resembles a collet chuck. To change tools one has the machine running and gently presses ones fingers onto the rotating chuck. This somehow allows the flex shaft buff or bristle brush or whatever to easily come out and be replaced. When one releases the slight pressure of the fingers the tool is fixed in place. Because the tool is running at all times this is very efficient and easy to use. Some shops have a special motor set up just for this tool for small jobs.
There was a time before polishing machines (and still in many places in the world where there is no electricity) when most polishing on metal was done with burnishers of various types. Burnished finishes are durable, bright and hard. Good burnishers may be filed out of high-carbon steel drill rod, hardened and tempered and hafted. The process is that a harder, polished material is rubbed with or without a lubricant (it is better with) against a softer material (the metal) giving it a similar degree of polish to that of the burnisher.
Burnishers are often used today to highlight edges in jewellery, to give a piece a ‘frame’ composed of very thin light streaks off the edge itself. They refine and define details in stonesetting such as the outside edge of a bezel or the fine work of a prong setting. They accentuate the edges of all parts of a setting or a piece of jewellery.
Agates, hematite, jade and so on make good burnishers but take a while to make. A nice stone burnisher is really nice to have. One can buy an interesting tumbled rock shape cheaply, take the bristles out of a metal ferruled paint brush and set and glue the stone in place in the ferrule to make an excellent stone burnisher equivalent or better than $20 ones from Germany. The ones in the diagram have been combined with a oil or acrylic paint brush so they function as a bench brush and burnisher combination.
Needle files may be converted to small burnishers quite easily by carefully grinding, sanding and polishing them without overheating them which would ruin their temper. I prefer a polishing compound called Fabulustre® for polishing steel. Used carefully it can even do some of the work normally done with fine emery on the steel prior to polishing.
Chasing tools may all be used as burnishers. Every chasing tool you make is another burnisher for your collection.
Hammers are burnishers with long handles.
Burnishers are often kept bright by having a piece of board with a thick piece of leather glued to it. One rubs the burnisher up and down the leather until a groove is formed. By placing ruby or diamond powder and a little oil in it one can keep the burnisher very shiny. Rouge and Fabulustre® also work.
An old bur can be broken off. The end heated is and then bent over. Harden and temper it to a blue on the body and light yellow at the tip. It is then smoothed and polished and when used in a flexible shaft it works like a rotary burnisher; like a hammer and fills in pits in castings, gaps and so on.
A commercial rotary burnisher may be purchased from Fischer in Germany. It is extremely efficient for filling pits before resanding and polishing. It consists of a number of roller bearings around a drum. Each functions like a little rounded hammer to smooth and blend the metal surface. The Fischer Company order number for a general purpose size is ‘Nietrad’ Number 3653/080.
Joe Dule in New York uses a steel clock gear on it’s spindle as a rotary burnisher. I use steel as well as brass gears as wax burs when carving filing waxes for casting models. It is also useful for riveting. Other versions include a nut soldered to a small bolt and old barrel burrs with 5 or 6 flat ground sides.