i'm trying this for my first time and having a bit of trouble. i started by taking the planer and just hacking away to get started, then moved to surforms, followed by sanding. one side looks nice and parabolic, while the other is more of a flat slant.... i set the blank aside out of frustration and i'm gonna go back to it monday or tuesday.... any suggestions on how to fix what i've got and maybe a way to do it better from start to finish next time? any advice would be great.
Rough work with the planer is good. Some people use a power sander but I don’t like it. Too easy to ruin a blank with that… I use different high density pads with heavy grit sandpaper (40), putting more pressure where depth is needed and less on the sides of the concave/spoon and I take the stringer down all the time to keep it level with foam with a convex spokeshave or planer; remember: concave shapes: convex tools. Convex shapes: concave tools. Flat shapes: flat tools. Easy, isn’t it?
My friend Stephane shot a short video while I was rough shaping a concave with the planer. I’m sure that some masters here do it much better but here it is, for what it’s worth:
ace hardware and probably many other stores sell an inexpensive convex surform. blade is maybe 2.5". i use that to take down the stringer first and then rough off the rest of the foam out to the rails. of course it does leave a rough surface. i use drywall screen wrapped around a sponge to finish the foam. a convex spokeshave would be nice to shave down the stringer. one of those little reverse japanese finger planes that clark foam used to sell will work on that also.
yes, i know that the pros use planers for everything. but i'm not a pro.
I don’t consider myself a “pro” either, even though technically I am one. People like Jim Phillips are pros and I’m not even trying to compare his work and mine. But the planer is the only tool that allows to work fast and true with a minimum of physical fatigue. You’re right about the reverse japanese finger planes for stringers. Guitar and violin-makers’ mini-planers are great, too.
I template the concave outline, then carefully rough it out with a surform. You can use tape around the outline to keep it crisp, if that’s what you’re after. I blend mine, so for me, it’s not necessary. The symmetry is eyeballed. The depth is measured and faded depending on entry rocker.
Triple stringers are harder, but the stringers are taken down with a mini spokeshave.
ok, thanks guys. appreciate it. i'm gonna give it another go on tuesday. see if i can work this one out.