...The goal is to exactly match the nut (block of wood the strings rest on next to the tuning pins), fingerboard and tailpiece, at each string position.
...Before we begin this stage, it is best to already have evened out the fingerboard tap tones so they are the same along the length of each string position and that the nut matches the fingerboard at each string position too.
...Now if we a fitting a new tailpiece, the first thing we want to do is make the tap tone the same from one end to the other for each string position. To do this we will tap with a low toned wooden pencil.
...Next, tap down on the far end of the tailpiece(blue arrows), directly behind the string in question and compare this tap tone to the fingerboard (which we hope is even all over in tap tone, which is necessary for all the notes to be even; see other article for details on making the fingerboard tap tones even all over.)
...Our tailpiece will be either the same as, higher, or lower in tone than the fingerboard. We will adjust the tailpiece to match our existing fingerboard. Our goal is to exactly match the fingerboard tap tone; when this is the case all the notes will be focused and at their most powerful.
..Tap just the area shown by the blue arrows, behind the string location for each string, and match this tap tone to that of the fingerboard under that string at the other end.
In this case the tap tones on that side of the talipiece can be raised by sanding or scraping that side as shown in the photo below:
...In order to lower the tailpiece tap tone for that specific string, scrape the area of the back of the tailpiece that corresponds with that string to lower the tap tone of the tailpiece for that string at the string bar for that string.
...When adjusting on an instrument, you must protect the varnish and the tail gut for damage. What I tend to use is several layers of manila folder paper with a semi-circle cut out of the center of one long side. I slide this cut out portion under the back of the tailpiece but over the tailgut to portect both areas. I find that the wood end grain of the wood is difficult to remove with a scraper so you might want to use a small sanding board, or a file.
...Remove a small amount of wood from the back edge of the tailpiece at a time and continually tap the string position on the string bar to compare with the fingerboard until exact agreement is reached. Adjust for each of the strings using the side scraping to raise that side of the tailpiece if too low compared to the fingerboard and lowering individual strings by removing wood at the corresponding area at the back of the tailpiece if that strings tap tone is too high at the tailpiece..
...Minor adjustments can also be made in this front surface area to lower tailpiece tap tones by sanding or filing this area evenly all across the front edge with a narrow sanding board, or just the underside of the front of the tailpiece to preserve its appearance .
...Be sure to protect the underside of the strings as well as the varnish from abrasion. (I like to lay a piece of manila folder paper under the tailpiece as it is durable).
...If only one side is slightly too high, then sand so that material is only removed from the side that is too high at present. If only one string is a little bit high, then scrape or sand material from directly in front of that string positionl
...Be sure that the front surface stays in a straight line, if possible, for best appearances sake, or scrape the wood from the underside of the front edge so it is not visible from above..
