For a small musical instrument I need a thin sheet of spruce (1.5mm). Normally I’d just buy a guitar or lute top, but for this one I need the highest quality I can get, with very narrow rings. So my idea is to saw down a blank for a violin top (25mm at its thickest point). I need to do this with as little waste as possible, because a good spruce top can cost 100-300€.
Is there a way I can do this with hand tools?
1.5 mm with hand tools? The only thing I can think of is a planer to get in the ballpark and then sand. Lots of sanding. Because if you used a tool to do it, it would be a drum sander.
You can absolutely do this with a hand plane, even less than 1.5 if needed. Specialty planes for musical instruments exist too.