Nice work @robin. Those little diamonds are a very common way to support the crack but I’ve just heard recently about the use of Japanese paper can be used, pasted along the inside of the crack. It tends to be…   Read more»

You could always cut layers of 1.5mm ply or 2mm MDF and laminate them together using laser cut dowel holes for alignment.
Darren

I shaped the soundboard seam diamonds today and glued them in. I also put them along the repaired crack in the soundboard, it might affect the sound qualities, but I doubt if I’ll notice it.

Last friday I playd with my band Lemon Curry at a pub in Zaandam. The audio isn’t very good, but we had fun!