Proper Soundboard Crack Repair

Repairing soundboard cracks the traditional way, by carving them out with a hand shimming tool, is tedious and seldom results in a perfect fit between shim and board. To best restore the structural integrity of a cracked soundboard the damaged wood should be replaced with new, joined as perfectly as the original soundboard planks.

The router base and custom bit shown here allow you to do just that for quality, permanent repairs. The base is made of UHMW Polyethylene with a metal bracket and special hose clamp to attach your power source. This can be either a small air die grinder as shown here or the hand piece from an electric Foredom tool. For shops equipped with compressed air, the die grinder is the best choice. Air die grinders are compact, run at true router speed, and are useful for many other shop jobs.

Features of this system:

The compact design reaches very close to the rim and bridges.

The 1" x 1" x 1/8" aluminum angle metal fence (purchased separately from your local hardware store) mounts instantly to the soundboard using our double-stick 3M Mounting Tape. There is no need to drill holes in the soundboard or rig up complicated clamping arrangements. The Router Base rides along the fence like a mono-rail, guaranteeing complete control with no danger of veering off course.

The base has both cross-wise and lengthwise fence slots; this allows the router base to slide along the guide fence in two modes, either parallel to the fence, or crosswise to the fence, depending upon the location of the crack in relation to the rim and bridges.

The air tool mounting bracket adjusts fore-and-aft on the base. This allows you to increase the width of the groove up to 7/8" to clean up wandering or multiple cracks without relocating the guide fence. Multiple fence slots in the router base allow routing of two exactly parallel grooves, without moving the fence, for replacement of panels up to 5 1/2" wide.

The router base includes a 10 page manual, Router Repair of Soundboard Cracks, covering the complete soundboard repair process from start to finish. For free download click icon below.

Router Repair of Soundboard Cracks (494 KB file)

Router Base price: $ 64.00

Soundboard Router Bit Custom made to our specifications, this bit lets you achieve perfect, machined wood joints in a fraction of the time required for hand shimming. The two-flute solid carbide design will not clog or burn and is ideal for use with our router base.
	Specifications: two flute solid carbide, American-made taper: 20º (10º per side). shank: 1/4" tip diameter: .10" cutting length: 1/2" overall length: 2" Bit price: $44.00

Soundboard Shims These shims match the angle of our soundboard router bit, for those who prefer to purchase ready-made shims rather than cutting their own. They are made by soundboard supplier André Bolduc of Quebec, from quarter-sawn Canadian white spruce. We stock them in three widths.
Sizes: Width of bottom tip: 2.2mm, 3.5mm & 5mm Height: 15mm Length: 1 meter (39")	The shims are 15mm tall, about 70% taller than the average soundboard thickness. Thus, they will fit grooves of varying width, depending upon how far they are seated into the board (after notching around the ribs). Their 39" length is adequate for most work, and can be end-butted if necessary to create a longer shim.
Min. order 6 shims (can be assorted sizes) Price: $2.75 ea.

Mini Air Die Grinder

Shown in the photos of the Soundboard Router Base above. Very compact yet powerful, it uses only 3cfm @ 90psi. (A typical 2 1/2 h.p. compressor will do, but a larger one will allow more "off" time). With a rotary rasp or small drum sander in the chuck, this tool is also very useful for freehand carving and shaping jobs such as fitting pinblocks to plate flanges. Size: 1 9/16" diameter x 6 1/2" long; chuck: 1/4"; imported.

Die Grinder price: $29.00