Tid-Bit 11 - Making a Burnisher
Burnisher 101
How to make your own
Thinking about burnishers brings to mind one of my first MART’s. Never had I imagined there would be so many specialized tools for working on clocks and watches. And, while I had no idea what-so-ever what burnishing was all about, one savvy table holder made it clear that you had to have a burnisher if you ever wanted to work on clocks. I still have that burnisher, and several others that are similar - you just can’t have too many tools - especially ones as important as burnishers! Not that I knew how to use them, even when I was buying numbers two, three, and, well, you get the idea. If you would like to learn more about such burnishers I highly recommend David LaBounty’s article in the June 2006 NAWCC Bulletin, starting on page 323.
When I read David’s article I was struck by his statement “A true test of skill is burnishing a pivot by hand. It takes many hours of practice and frustration just to become moderately proficient and years before the task becomes routine.” Having tried to use commercial burnishers on the pivots in the clocks I love (Vienna Regulators), I can understand his comment. It is sort of like trying to drive a small nail with a 6 pound sledge hammer. My first MART find, and burnishers like it, is the reason it is so important for you to make your own burnisher.
Figure 1 gives a side-by-side comparison of three burnishers - the top two are commercially made, the bottom one is the burnisher handed down to me by my mentor, Ray Ashcraft.
Figure 2 – Elgin Sapphire Burnishers
The bottom burnisher in Figure 2 has had a part of the pivot file (on the right hand end) broken off – both the Elgins and the commercial burnishers in Figure 1 have files at one of the burnisher. I find both the files on the steel burnishers and the aluminum oxide slip (pivot file) on the Elgin burnisher to be very coarse, only appropriate for the initial flattening of a very badly damaged pivot. Most of my pivot restoration work involves the use of hard Arkansas slips – as discussed in my first Tid-Bit (NAWCC Bulletin – “Got Stones”, October, 2009).
Whilst too small for most clock work, the Elgin sapphire burnishers are perfect for watch work, and very appropriate for the smallest pivots in very fine clock mechanisms.
Ray Ashcraft, a retired railroad watch inspector, used burnishers to restore both clock and watch pivots. Fortunately he was not one to just accept the tools handed to him – he spent most of his career trying to make the best burnisher possible. Each time I pick up the burnisher he passed on to me I am reminded of his efforts – not to mention when I open my burnisher drawer and see perhaps 15 other examples that were not quite as good. With a lead-up like this you are probably beginning to think that making a burnisher is quite daunting, and well beyond the capabilities of a novice clock or watch restorer. Hopefully this article will disabuse you of that notion.
Size Matters
Not to long ago I was reading an excellent article on moving pivots when assembling a mechanism (Some Thoughts on Pivot Locator Hooks - Bulletin Article 4/2010, pg 186). The author presented a number of examples of hooks and pushers that can be used to move pivots around when trying to get them to slip into their appropriate holes. I bring this up because I think it is an excellent lead-in for discussing why size matters in things like burnishers.
An experienced craftsman can do phenomenal work with tools that only serve to expose a mere mortal’s lack of skill. When dealing with fine pivots in Viennese or perhaps French movements, it doesn’t take much pressure to inadvertently bend, or even remove a pivot. Brings to mind a years-duration mechanism one of my customers tried to reassemble. Whilst he only bent 2 pivots using a pusher like the top one in Figure 3, well, that is still two too many.
At one point, after bending a pivot in a Vienna Regulator, I decided to make a pivot locator that would be a bit more forgiving. It is the second tool from the top in Figure 3.
