Chapter 9

Gluing up the Soundbox

and Drilling the Neck

    Now that I've got all of these braces cut, I can start actually gluing these pieces together.  This is a long process, tedious and time consuming.  But to get it right, it's necessary to glue one piece at a time, using as many clamps as you can fit onto each assembly.

    The first thing I did was cut the sound hole in the back of the harp.  Here I had considered a variety of fancy or elaborate designs to fit in with the Celtic decorations that will be added later.  However, I've got to be able to reach into this sound hole when the harp is complete to thread each of the harp strings through the soundboard, so I decided instead on a simple design.  I laid out the shape of the hole on one half of the back, clamped both pieces together, and cut out both sides at once.  Then I edge glued the two halves together.

    This is the back side of the soundbox, once the two halves have been edge glued together.  These pieces are only 1/4" thick, and the glue joints at either end of the assembly are only 6" to 8" long.  I'd feel better if these glue joints were reinforced just a little, so I grabbed some thin Maple stock, and fashioned a couple of doublers to glue down on this joint on the inside surface of the back.

    This shot shows the 2 doublers glued in place, and under clamp pressure.  These pieces were cut from stock just .150" thick, and are only an inch wide.  In spite of their light weight, they will add sufficient insurance to these glue joints that I won't have to worry about them separating later. 

    Here I have started gluing the corner braces.  I cut the braces first, short enough to allow room for the bottom plate of the harp (the base), and also for the top blocks of the soundbox where the neck will attach.  Because the sides and 1/4 sides get so narrow at the top of the soundbox, it was also necessary to taper these braces at the top end, so they would not interfere with each other.  Patience and careful alignment is necessary here, so each successive piece will line up and form a tight joint.

    This detail photo shows the taper that had to be cut on both sides of one of the braces (middle piece in photo).  I laid out a center line on the very narrow 1/4 side panel, and trimmed the brace back far enough that it did not cross over the center line.  Doing the same with the mating brace ensured that there would be no interference.  The leg of the brace that will glue to the side of the box only needed to be trimmed enough to clear the soundboard brace that will be added later.

    While the glue is setting up on all of these assemblies, it seems a good time to take care of a few other tasks that need to be done.  Going back to my original full scale drawing, I used the same method of transferring the locations for the tuning pins and bridge pins onto the neck of the harp with an awl.  Then it's over to the drill press.  Here I am drilling the holes for the bridge pins.  I use a brad point drill, and drill deep enough to allow for some adjustment of the distance of the string to the neck.  Do not drill all the way through the neck in this operation.  Adjustment of the height of these pins will be necessary later when I install sharping levers.  The holes should provide a "slip fit" on the diameter of the bridge pins.

    Here I have switched to a 1/4" diameter brad point bit, and am drilling the tuning pin locations.  These DO go all the way through the neck, so I've got a piece of scrap pine clamped to the back to minimize tear out of the material on the back side of the neck.

    Here I have flipped the neck over, and am using a special taper reamer to ream the holes to fit the tuning pins.  There are 2 standard sizes of tuning pins for harps like this, #4 Pins and #5 Pins.  Each size comes in a variety of lengths.  There are several sources for these pins, and if you want this info. please write me and I will provide sources.  Whoever you order your pins from will also be able to supply the appropriate reamer to fit those pins.  Sneak up on the depth of this reaming operation, until the position of the tuning pin is right for your harp.

    Here you can see that the tuning pin is approximately centered in the neck when it gets tight on the taper, as viewed from above.  This is just about right.

    While all of this drilling and reaming was going on, I kept going back to the soundbox assembly, and adding more pieces.  Here the last piece has been glued in place, and I've got as many clamps as I can reasonably get on there holding it in place

    After hours of gluing and clamping, over and over again, there is a soundbox.  At this point, it is surprisingly strong and rigid for it's light weight.

Move on to Chapter 10

Return to Front Page

Harpmakers Build A Harp Page -- Revised: 10/14/02
Copyright & copy; 1996 East-Wood Products
Please send inquiries and comments to:
Project@harpmaker.net