A little while ago I took interest in burnishing as a method of polishing without having to remove material. I recently got around to purchasing an agate burnish with a ball point tip. I made up a .999 silver band, fused the joint, filed and sanded and then burnished it. It’s nice and shiny on the edges but the middle of the band is still not burnished. Do I need something heavier like a steel burnisher? Do I need a better lubricant? (I was using spit) Do I need to file it smooth first? If so, that which would defeat the purpose of burnishing.
I would also like tips on how to burnish rings in general. How do I hold them, how do I burnish the inside and so forth,
Hi there,
Burnishing is my preferred method for finishing. As you have already found, there are a number of tools that can be employed for the process. Agate and steel burnishers are great- especially for edge and spot burnishing, and for scratch repair. Having a number of hand burnishers with various shaped edges and contours is very useful. I found some really nice burnishers in Japan, that are almost like fat needles, and come in a few sizes. If I can find out what to call them, I’ll send the info your way.
The biggest issue you will find is that burnishing for extended periods of time is very hard on your hands. The older you get, the more you will notice…
However, your question of un-reached areas is one that needs resolution. For an all-over burnish, that will knock your socks off, this is my method:
Fine sand with sanding cloth or foam (I use 3M paint polishing sponges in Ultra fine and microfine). Use the highest grits you can locate. Typically 800-1000 is good. Finer grit is better if you can locate it.
Once I have inspected my piece and determined that the surface is just as I desire, I place my piece in a vibratory tumbler loaded with stainless steel polishing media. I use a mix of balls, saucers and pins. 5 pounds of media is adequate for most pieces.
My tumbler is a Raytech TV-5. I place the media into the TV-5 with a small amount of water and a low-suds detergent, or a few drops of blue soap (50/50 laundry detergent & household ammonia.) The soapy water acts as a lubricant. Rio sells some specialty solutions for vibratory tumbling, but I’ve never found them worth the money- YMMV.
Tumble your piece(s) from 15 minutes to an hour, depending on the size and complexity of the surface. You cannot believe how amazingly bright and gleaming the metal will be when it is finished this way. And the best part is that it is incredibly gentle and will not thin your metal.
Although this is not burnishing, perhaps a hint from restoring brush finished or non-reflected finishes on stainless steel will help. Many watches are finished this way. I’m often asked to take out small scratches.
I sand using a small piece of 1000 or 1200 grit 3M polishing sponges held in a locking tweezers and lubricate with sewing machine oil. Depending on the piece, I sometimes use a dish washing detergent and water mix to lubricate. I think both of these lubricants would work equally well when burnishing.
If you are having problems reaching those small little creased areas in your design, I learned slick tricks long ago. The wood working industry sells powdered grits. Way back when decades ago I purchased 6 different grades of grit up to 6000. I use tooth picks that I chewed on to make a little more pliable and wet to hold a dip full of the grit. I can work thos tight areas. If it is really really tight or edges if a small opening, i use string decending in thickness down to heavy threads. Doing that I had an ephifany moment. Old style and I havent seen it in a long time, there was dental floss that has just a wee bit if an abrasive to it. It was not like today that is a fumky breakable string. It was flat and thin. Tough as nails needing a cutter to cut through it. That floss could reach any surface I needed to hit. Between my floss, toothpicks, and powdered grit, I can get any spot sanded to a mirror shine.
Like Aggie P I have used up a mile or so of strings for deep places needing polish.
I will run a string up tight in an old German Saw frame. Strop it through some polish and have at the work. I have used every type of string from Butcher’s String down to dental floss but my favorite is woven fishing line. Mono-filament flat out doesn’t work for this purpose. If fishing line will stand up to a Pike it will stand up to some pretty aggressive saw action. Woven strings used for this purpose stretch quite a bit and need to be re-tightened fairly often but I find the effort satisfactory.
Great idea. I use scotch stones of different grits that I can file to any shape to get into tight spots. They are hard to find these days. So I may have to use your toothpick and abrasives idea when my scotch stones finally give out.
Jo
Don- Thanks. I’m such a dummy. Insert palm smack to forehead here. I never thought to use a saw frame for that. What a great trick.
I learned to do old school German style Thrumming. I have an assortment Mitchels Abrasive cords and tapes as well as several strands of cotton twine with different polishing compounds rubbed into them that I keep hanging from a nail on the corner of my bench. I use them to get into tight spots like under galleries. All the stretching and rubbing kills my arthritic hands. A saw frame makes so much more sense. In the attached photos you can see how the stone reflects off of the shiny under gallery of a ring my sweetie Timothy Green carved. It’s not my work. I just did the grunt work on this one. - Jo
You are welcome Jo. It can be cumbersome but it works for me. My fingers are pretty messed up so this is my modification to thrumming. And I grab enough good ideas from you so we are even.
Running steel in a TV-5 - It’s a small machine not rated for steel so - it isn’t turning the steel effectively, it is jiggling it - a small rotary tumbler would be far more effective, require less steel and work better. Effective media motion in vibratory tumblers is a torroid - essentially donut shaped, rolling toward the center.
Our silversmiths use pumice stone and charcoal to finesand surfaces. I often use a strip of leather and differen thicknesses of cottonthread dangling from a nail and put polishing compound on it. Works well for difficult edges. As well as wooden toothpicks filed to shape.