Hi all,
So I'm going to be building some guitars. In the past, I've bought and used pre-made radius sanding blocks, but I'd rather make them myself this time out (I've since sold all my guitar tools many years ago, hence I'm now starting from scratch).
For those not in the know, all they are is a length of wood, about 100mm wide and 150mm-1.5m long with a concave profile cut into it at a given radius (a half-pipe essentially), usually measured in inches (12-16 being common). These are used for sanding down flat, square fretboards to impose a radius across their width.
There are tons of tutorials on how to do this with a powered router, but I neither own nor want to own one and prefer to handle this by hand if possible. My first thought was to adapt an old Stanley no.4 with a heavily-cambered blade, not too dissimilar to a scrub. But this poses a width problem. I suppose it could be possible to do it in segments and glue them up, but I'm not sure how accurate that would be.
I thought of carving it in with a rasp. That would work for a short section, but I doubt I'd be able to do it accurately along longer lengths. Again, I suppose I could do multiple blocks and then glue them together, but it doesn't sound like an optimal method.
Am I missing a really obvious answer? Moulding planes, perhaps? Are there ones big enough for this kind of operation? My initial inquiries haven't found anything, or I'm not looking for the right thing. There's the issue that if I did find a moulding plane, I would need multiple to give me the different radii.