Repair is an important part of Lutherie and soundboard cracks are a common repair. This uke was shipped in a hard case and cardboard box to the East Coast and FedEx must have put it on the bottom of the pile. A long crack on the soundboard brought it back to my workshop. Heres the fix.
First I attached tiny but powerful magnets underneath and on top which brought the two sides of the crack perfectly together. then thin superglue was wicked into the crack tightly rejoining it and probably making it stronger than the original wood grain. Then as a precaution two tiny holes were drilled exactly in the crack and a thin steel wire inserted and drawn out the sound hole.
The wire is then connected to a maple patch which will have hide glue put on its surface and be pulled back inside the instrument and up against the bottom of the soundboard over the sealed crack.
The wire is attached to these little winches which I made with wood scraps and geared tuners. The patch is pulled up tight with the winches until the hide glue sets the patch in place.
I am able to see what is going on inside with the help of this lighted mirror, about $15,00 bucks at Grizzly.
You can see the mirror image of one of the patches in place as the hide glue sets. Next day I will remove the wire, refinish the top and this tenor will be as good as new.