Epiphone Dove: Shim Saddle

Related Topics: | Epi. Dove: Cracked Bridge |

Note: Shimming a saddle will compromise an instrument's tone and volume. Whenever an instrument's sonic characteristics are a priority, a saddle should be replaced rather than shimmed. Similarly, it is tonally preferable to replace a loose saddle rather than repair said saddle.


1. A Loose Saddle diminishes an instrument's sonic qualities and can even cause a bridge to crack. If a saddle is not properly contacting the bridge it cannot fully transmit the soundwaves created by the strings to the rest of the instrument. Also, if a saddle is loose enough it will act like a lever and crack the bridge at one or both ends of the saddle slot. This saddle is .016" too thin	2. This Saddle Has Already Been Shimmed, probably by the dis- tributor (the Gibson corporation) before it was sold. Shimming a saddle is a common practice amongst manufacturers and distributors of foriegn made student model guitars. This plastic shim is substantially nar- rower and shorter than the "footprint" of the saddle. These two factors (the shim's size and material) combine to exacerbate the diminishing effects on this guitar's tonal characteristics caused by the loose saddle. The real problem here is that the neck angle is too steep. Unfortunately, the cost of a neck reset would likely be greater than replacing this guitar with a used one of the same make and model.


3. Laying out the Shim. I chose Indian rosewood because it is similar in density to the "ebony" used to manufacture this guitar's bridge. A piece of masking tape makes my pencil tracing of the saddle's foot- print easier to see for rough cutting.	4. Rough Cutting the Shim with a coping saw only takes a minute. We prefer to use hardwood shims over plastic ones because they have a smaller negative effect on tone. We use hardwoods of the same species as an instrument's bridge whenever possible. If the species of hardwood is not at hand we will use a wood of the most similar density to the bridge material for the shim. Since fabricating a shim is a way to keep costs down we don't go over- board selecting the species of the shim.


5. Shapping the Shim. A block plane with a sharp blade is the tool of choice for this task. I'm establishing the final width of the shim. I want the shim to be about .003" narrower than the bottom of the saddle slot. This will maximize tone transfer while at the same time leave the shim loose fitting enough that it can be relatively easily removed with the tip of a knife. This high quality block plane was made by Lie-Nielsen Toolworks.	6. Rounding the Ends of the Shim. The shop's disc sander is the perfect tool for this job. Again, I'll make the shim just a few thousandths of an inch smaller in length than the bridge's saddle slot.


7. Thickening the Saddle. I'm swabbing one side of the saddle with super glue accelorator charged q-tip.	8. Thickening the Saddle Cont. Laying down a layer of medium viscosity cyano accrylate (aka: super glue) will increase the thickness of the saddle.


9. Thickening the Saddle Cont. Flooding the un-cured super glue with accelorator from a pippette will expidite the curing process.	10. Sanding the Saddle to Thickness. After letting the glue cure for a couple of minutes I'm sanding the super glue thickened side of the saddle flat with 600 grit wet dry sanpaper (from Stew Mac) on the shop's dead-flat granite slab.


11. Checking the Action with the saddle in place without a shim will indicate how thick the new shim will have to be. The distance between the top of the 12th fret and the bottom of the low e string is 2/32". The same measurment for the high e string is 3/64". I want my final measurements to read 3/32 for the low e string and 2/32" for the high e string. Since I'm taking my mea- surements at the 12th fret (which is the middle of the scale length of the guitar) any adjustments I make at the saddle will have one half the effect as measured at the 12th fret. This means that the shim has to taper in thickness from 1/32"on the treble end to 1/16" on the bass end.	12. Measuring the Shim for Thickness. The shim measures an even .118" accross its length. The final thick- ness of the shim will be .031" tap- pering to .062" (I've converted my final thickness to thousandths of an inch so I may more accurately measure the shim with the shop's calipers).


13. Thicknessing the Shim. I'm using our shop made bench dog to stabalize the shim as I plane the shim to its final taper and thick- ness. Planing exotic hardwoods to my very thin and tight tolerances is only possible with a dead-flat soled plane with a razor sharp blade. When- ever I'm making such fine cuts I prefer to use our shop's Lie-Nielsen #9 1/2 block plane.	14. Thicknessing the Shim Cont. I've been periodically checking the thickness of the shim between cuts. I first established the taper (a thick- ness differential of .031" from end to end). Then I evenly planed the shim down to it's final thickness.


15. Checking the Saddle Protrusion. With the completed shim in place, I seated the saddle and made a pencil mark accross the side of the saddle to show me how much of the saddle is protruding from the bridge. Ideally, half of the saddle or less should protrude from the bridge as too tall of a saddle will put too much tension on the top of the guitar causing damage in- cluding cracking the bridge at the ends of the saddle slot. However, the value and life expentency of a student instrument of this quality combined with the cost of the other repairs we performed on this in- strument make shimming the sad- dle the most appropriate repair for this particular instrument.	16. A Shimmed and Properly Fitted Saddle. Even with a shim, the tone and playability of this guitar are much improved.