Hi all,
There is a point when a bunch of glued together pieces of wood becomes a musical instrument. For me, that point is the day the soundboard is glued into the case. Everything that will effect the tone of the instrument will have already been done. In this post, we’ll make the ribs and cut-off bar, glue the bridges, 4’ hitchpin rail, cut-off bar, and ribs to the soundboard, and, finally, in Part B of this post, permanently install the soundboard and make and install the hitchpin rails. Let’s get to it.
We’ll start by making the ribs and cut-off bar. These parts will be glued to the underside of the soundboard and serve to both stiffen it and divide it into separate sections for tonal reasons. As for the woodworking, they are quite simple to make on the tablesaw. The ribs are 7/16” tall and ½” wide at their bases – tapering to about 3/16” wide at their tops. The cut-off bar is slightly larger in all dimensions. Here’s what they look like in their positions on the underside of the soundboard. The picture shows the 3 ribs on the bottom right, the cut-off bar just above them, and the 4’ hitchpin rail above the cut-off bar.
Now that all of the parts have been made, it’s time for some glue-up. We’ll glue the two bridges first. Before we glue, we’ll undercut the last ¾” of the 8’ bridge about 1/8” high. This allows the soundboard to vibrate a little more freely at this end of the bridge whose far end is very close to the spine side of the case. Every bit of increased flexibility of the soundboard in this area helps.
Now, we glue. Traditionally the bridges are clamped with go-bars while the glue sets.
Since I’m not set up for using go-bars, we’ll use padded nails and some rudimentary bow clamps to apply the needed pressure. First we temporarily place the 8’ bridge in position and trace its outline onto the soundboard. Then we apply glue (Titebond original) to the soundboard and to the bottom of the bridge. Using the padded nails, we nail the bridge down through the soundboard and into the workbench – making certain that the nails go into the locater holes we made in the soundboard in Part 19. After all of the nails have been driven, we add some 2x2’s and other assorted scraps long enough to be clamped at each end and run them over the bridge every 6” or so. The next two photos show this simple, but effective way of bridge clamping. The only drawback to this method is having to glue the two bridges down one at a time because the bow clamps are in the way of the 4’ bridge. Then again, what’s the rush?
After a few hours the clamps and padded nails are removed. The nail holes are plugged with toothpicks and a little glue.
Now we’ll glue the 4’ bridge onto the soundboard. Since this bridge is much smaller in size than the 8’ bridge, we’ll use padded nails only to provide clamping pressure.
A few hours later, we remove the padded nails, fill the nail holes with toothpicks, cut off the toothpicks from both bridges, sand them flush to the bridge tops, and clean up any excess glue. Here’s a photo of the installed bridges.
Next, we flip the soundboard over to work on the underside. First to be glued is the 4’ hitchpin rail. This part is difficult to clamp and we really don’t want it to ever come loose. It will be subject to a lot of tension from the 4’ strings that will be hitched to it so the glue joint must be strong. For this reason, we’ll use the bow clamp method to apply pressure and we’ll use a 1 hour set epoxy, not so much for the strength of the glue, but for the extra time it allows for positioning the clamps. To add to the difficulty, the bridges have already been glued to the top surface of the soundboard so the board will not lie flat on the workbench. To overcome this problem we’ll tape some ¾” scraps on the top surface of the soundboard, between the two bridges (directly over the area where the 4’ hitchpin rail will be glued). This will take the clamping pressure off of the bridges and allow for a firm backing directly on top of the 4’ hitchpin rail that we’re attempting to glue down.
If you remember, we drilled two locater holes in the soundboard for this rail. Using two nails sticking up from these holes, we locate the 4’ hitchpin rail to the underside of the soundboard (which is now facing up on the workbench). We trace the outline of the rail onto the soundboard and remove the rail – but we leave the two nails sticking up so we can find them easily without having to flip the soundboard over to find the proper holes. Epoxy is applied to the soundboard and the 4’ hitchpin rail and the rail is placed onto the soundboard using the locater nails to position it correctly. Then the bow clamps are applied for pressure. Here’s the setup.
While the epoxy sets, we’ll do some work on the rose and the rose hole. Instead of gold leaf, which has become prohibitively expensive, we’ll be using Golden Acrylic Iridescent Gold (fine) paint. This color is an almost exact match with 23 karet gold leaf – so good, in fact, that I have used both gold leaf and this paint on a single instrument. I don’t like imitation gold leaf. It’s very difficult to put on smoothly and will always tarnish. A topcoat of varnish or Krylon is necessary to slow down, but not eliminate, the tarnishing. It also deadens the look of the gold and actually is far inferior to the Golden paint. Here’s the rose after painting.
Traditionally, the rose is surrounded by a circular band of text that usually contains the builder’s name and the year the instrument is built. This text band is then surrounded by a floral arrangement painted onto the soundboard. We’ll use a tool the original makers didn’t have available to them – a computer, to make the text band. Here’s a photo of the rose and text band in position on the soundboard. The small amount of soundboard that shows between the rose and the text band will be painted gold to match the rose. Sandy will paint the wreath of flowers when she starts painting the soundboard.
Now the cut-off bar and ribs are glued to the underside of the soundboard, using the bow clamps for the cut-off bar and speed clamps and weights for the ribs. After the glue dries, the rose is glued in place. Traditionally the rose is held in place by soaking strips of cloth in glue, applying the strips to the corners of the rose, and letting the glue dry. This method has been used for hundreds of years and I’m sure it works well. However, being somewhat paranoid and non-trusting, we’ll first put a dab of quick-set epoxy on each corner and clamp it with finger pressure until it sets. Then we’ll add the glue-soaked strips to the corners of the rose. The epoxy is probably over-kill but it can’t hurt and I sleep better knowing the rose is there for life. Here’s the final shot of the underside of the soundboard.
By the way, I didn’t mention the true function of the rose. That’s because it doesn’t have one. Some folks believe, or used to believe, that it allowed air to get into the cavity under the soundboard, but that would only be true if that cavity were air-tight – which it isn’t. The rose is purely decorative - many instruments don’t have a rose at all and they sound perfectly fine.
This post is continued in part 20-B ...................................
There is a point when a bunch of glued together pieces of wood becomes a musical instrument. For me, that point is the day the soundboard is glued into the case. Everything that will effect the tone of the instrument will have already been done. In this post, we’ll make the ribs and cut-off bar, glue the bridges, 4’ hitchpin rail, cut-off bar, and ribs to the soundboard, and, finally, in Part B of this post, permanently install the soundboard and make and install the hitchpin rails. Let’s get to it.
We’ll start by making the ribs and cut-off bar. These parts will be glued to the underside of the soundboard and serve to both stiffen it and divide it into separate sections for tonal reasons. As for the woodworking, they are quite simple to make on the tablesaw. The ribs are 7/16” tall and ½” wide at their bases – tapering to about 3/16” wide at their tops. The cut-off bar is slightly larger in all dimensions. Here’s what they look like in their positions on the underside of the soundboard. The picture shows the 3 ribs on the bottom right, the cut-off bar just above them, and the 4’ hitchpin rail above the cut-off bar.
Now that all of the parts have been made, it’s time for some glue-up. We’ll glue the two bridges first. Before we glue, we’ll undercut the last ¾” of the 8’ bridge about 1/8” high. This allows the soundboard to vibrate a little more freely at this end of the bridge whose far end is very close to the spine side of the case. Every bit of increased flexibility of the soundboard in this area helps.
Now, we glue. Traditionally the bridges are clamped with go-bars while the glue sets.
Since I’m not set up for using go-bars, we’ll use padded nails and some rudimentary bow clamps to apply the needed pressure. First we temporarily place the 8’ bridge in position and trace its outline onto the soundboard. Then we apply glue (Titebond original) to the soundboard and to the bottom of the bridge. Using the padded nails, we nail the bridge down through the soundboard and into the workbench – making certain that the nails go into the locater holes we made in the soundboard in Part 19. After all of the nails have been driven, we add some 2x2’s and other assorted scraps long enough to be clamped at each end and run them over the bridge every 6” or so. The next two photos show this simple, but effective way of bridge clamping. The only drawback to this method is having to glue the two bridges down one at a time because the bow clamps are in the way of the 4’ bridge. Then again, what’s the rush?
After a few hours the clamps and padded nails are removed. The nail holes are plugged with toothpicks and a little glue.
Now we’ll glue the 4’ bridge onto the soundboard. Since this bridge is much smaller in size than the 8’ bridge, we’ll use padded nails only to provide clamping pressure.
A few hours later, we remove the padded nails, fill the nail holes with toothpicks, cut off the toothpicks from both bridges, sand them flush to the bridge tops, and clean up any excess glue. Here’s a photo of the installed bridges.
Next, we flip the soundboard over to work on the underside. First to be glued is the 4’ hitchpin rail. This part is difficult to clamp and we really don’t want it to ever come loose. It will be subject to a lot of tension from the 4’ strings that will be hitched to it so the glue joint must be strong. For this reason, we’ll use the bow clamp method to apply pressure and we’ll use a 1 hour set epoxy, not so much for the strength of the glue, but for the extra time it allows for positioning the clamps. To add to the difficulty, the bridges have already been glued to the top surface of the soundboard so the board will not lie flat on the workbench. To overcome this problem we’ll tape some ¾” scraps on the top surface of the soundboard, between the two bridges (directly over the area where the 4’ hitchpin rail will be glued). This will take the clamping pressure off of the bridges and allow for a firm backing directly on top of the 4’ hitchpin rail that we’re attempting to glue down.
If you remember, we drilled two locater holes in the soundboard for this rail. Using two nails sticking up from these holes, we locate the 4’ hitchpin rail to the underside of the soundboard (which is now facing up on the workbench). We trace the outline of the rail onto the soundboard and remove the rail – but we leave the two nails sticking up so we can find them easily without having to flip the soundboard over to find the proper holes. Epoxy is applied to the soundboard and the 4’ hitchpin rail and the rail is placed onto the soundboard using the locater nails to position it correctly. Then the bow clamps are applied for pressure. Here’s the setup.
While the epoxy sets, we’ll do some work on the rose and the rose hole. Instead of gold leaf, which has become prohibitively expensive, we’ll be using Golden Acrylic Iridescent Gold (fine) paint. This color is an almost exact match with 23 karet gold leaf – so good, in fact, that I have used both gold leaf and this paint on a single instrument. I don’t like imitation gold leaf. It’s very difficult to put on smoothly and will always tarnish. A topcoat of varnish or Krylon is necessary to slow down, but not eliminate, the tarnishing. It also deadens the look of the gold and actually is far inferior to the Golden paint. Here’s the rose after painting.
Traditionally, the rose is surrounded by a circular band of text that usually contains the builder’s name and the year the instrument is built. This text band is then surrounded by a floral arrangement painted onto the soundboard. We’ll use a tool the original makers didn’t have available to them – a computer, to make the text band. Here’s a photo of the rose and text band in position on the soundboard. The small amount of soundboard that shows between the rose and the text band will be painted gold to match the rose. Sandy will paint the wreath of flowers when she starts painting the soundboard.
Now the cut-off bar and ribs are glued to the underside of the soundboard, using the bow clamps for the cut-off bar and speed clamps and weights for the ribs. After the glue dries, the rose is glued in place. Traditionally the rose is held in place by soaking strips of cloth in glue, applying the strips to the corners of the rose, and letting the glue dry. This method has been used for hundreds of years and I’m sure it works well. However, being somewhat paranoid and non-trusting, we’ll first put a dab of quick-set epoxy on each corner and clamp it with finger pressure until it sets. Then we’ll add the glue-soaked strips to the corners of the rose. The epoxy is probably over-kill but it can’t hurt and I sleep better knowing the rose is there for life. Here’s the final shot of the underside of the soundboard.
By the way, I didn’t mention the true function of the rose. That’s because it doesn’t have one. Some folks believe, or used to believe, that it allowed air to get into the cavity under the soundboard, but that would only be true if that cavity were air-tight – which it isn’t. The rose is purely decorative - many instruments don’t have a rose at all and they sound perfectly fine.
This post is continued in part 20-B ...................................
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