Installing a Skin Head using the prototype Beede Method

David Hyatt - 10/16/2006

Here is a very nice method of attaching the skin to the gourd. This is, again, not meant to be the definitive method - just one of many...

This was developed by Florida luthier and musician David Beede. David developed this at the request of a musician to replace the head on his Thornburg gourd banjo with a tensioning system that would be more adjustable

In his words (with some editing)...

This method makes use of 1/8" Delrin hoop to reinforce the skin edges and distribute the lacing tension evenly to the skin. It produces skin tension equivalent to tack-head banjos but with no glue or metal parts.

		Here is the system on a 10" canteen gourd that I made as a prototype for the project. I thought I would need 16 attachment points, but as it turned out this size head required only 8 tensioning points and so uses only 4 tensioning laces and 4 disks.
		This image illustrates how the lacing crosses at the middle back of the gourd. The lace material is 130 lb test braided polyester fishing line with virtually no stretch. You can also see the rubber backing on the disks for added friction and to avoid any marring of the gourd.
		The tensioning disks are 3/4" diameter oak, with three holes drilled into them. The knot is recessed into the disk. Under tension the disk is rotated counter clockwise causing it to "grab" the cord that runs through it. The lacing method makes it possible to tension two perimeter points on the head simultaneously with only one disk. This also automatically tensions the head using opposite tension points, which is ideal when tightening a banjo or drum head. This lace system is also a variation on the "truckers hitch" which is used to secure loads. It simulates a block and tackle and gives some mechanical advantage when tensioning.
		Perhaps the trickiest part is sewing the hoop into the edge while the skin is wet and pliable. I went with a zigzag stitch on the gourd below - since even though Dacron sail thread doesn't stretch - the zigzag pattern does allow for some "give" and movement.
		This is a Bob Thornburg gourd-jo I re-headed. Bob utilizes hardwood pegs glued into the sides of the gourd with leather laces and square slide beads for tensioning.
		You can see the sort of "D" shaped opening in this gourd. Bob's head followed the shape of the opening, while I used a round skin. The replacement skin is, calf skin, much thinner and more translucent. I learned making the prototype above that it's not necessary to notch the skin and expose the Delrin hoop. Holes flush with the hoop work fine.
		Here's a better look at the new system. In this case 16 tension points required 8 tension disks. I just sawed off the hardwood pegs and sanded and finished them. Now they look like decorative inlays.
		The laces all cross in the back producing a look reminiscent of a Native American "dream catcher." Since the lace system loops around the hoop, the disks can be positioned where they are most convenient. I've put them on the top so they are easy to grab with my right hand thumb and first finger to slide them. A slight clockwise twist while sliding eases the disk friction on the cord.