The Screw Mounted version of the JLD Bridge Doctor requires enough space behind the row (or rows, if it’s a 12 string) of bridge pins to accommodate the screw. Two different sized holes need to be drilled so the screw is flush with the top of the bridge; one that goes all the way through the bridge for the thread and another countersunk hole for the screw head. This blog post shows exactly how the screw is fitted. The screw head is around 6.5mm in diameter which, although small, can sometimes be tricky to find space for.
Ray purchased a Bridge Doctor fairly recently and had a very similar issue with his acoustic guitar. I would have recommended the JLD Bridge System (that uses a brass pin rather than a screw) however Ray was concerned that there wouldn’t be enough leverage to apply adequate pressure under the saddle. He therefore went for the Screw Mount version and came up with a clever way of fitting the device.
“The problem I encountered here was that my bridge slopes away towards the back of the guitar so that the counter-bored hole to hide the screw head had to be much deeper than would be needed for a thicker bridge. In order to completely hide the screw head the head sized hole went right through the bridge and only stopped at the guitars top. This was not ideal but I managed to resolve the problem by cutting an elongated slot approx 1 inch long and 0.25 inch wide into the bridge running parallel to the saddle into which i fitted a small steel strip drilled to take the screw. This distributed the force of the screw more evenly which allowed the screw to be tightened much more firmly than previously.
The Doctor was then set up against the rear block and over a period of days tension was gently increased.
This took the top of the guitar down until it was almost flat and has lowered the action and improved the sound.
Finally the slot in the bridge was filled with wood filler, sanded and painted to match the original ebony colouring.”
“In summary, the Bridge Doctor is a great inexpensive device to correct a bellied top but may require some additional considerations and extra work to suit the shape / thickness of the bridge.”
So, although it took a little more work than usual, the Bridge Doctor was successfully installed. I was interested to know how much of a difference the steel strip made with the tightening of the device. I recommend slowly tightening the Bridge Doctor because of the amount of pressure applied to the guitar bridge and top. We don’t want any exploding guitars! Evenly distributing the force of the screw across a larger area must have made a big difference?!
Another interesting point was the change in sound. Installing one of these devices will often change the sound of your guitar. The extra rigidity to the guitar bridge/top tends to increase sustain, volume and enhance harmonics. In my reply, I did ask what he thought about the change in sound and what differences he noticed. Here was his reply:
“The change in sound I refer to is a little difficult to describe. This guitar has always had a very mellow sound, bass heavy like a Martin dreadnought. It is a Martin dreadnought copy. What I did notice was that even though I put the old strings back on, I got a sound that was brighter. I can’t really describe it much better than that but it was definitely brighter. Maybe stiffening the top has reduced the amount of movement at the lower frequencies and let the higher ones dominate. Who knows?”
You can view the JLD Bridge Doctor and JLD Bridge System HERE
Thanks again for your review Ray! Much appreciated.