Saturday, February 5, 2011

Scrapers, smoothing everything up


I've been tuning up the belly. Some of the tuning is done on the outside and some on the inside. I cut the taper on the sides of the bass bar with a chisel. It's still too tall. By the way the glue/clamp setup worked very well, but so did the rub joints...I think. Almost all of the work I do once the main shape is carved is done with scrapers. I don't think I've said much about scrapers. Scrapers are just strips of metal with a smooth, sharp edge that cuts the wood like a very high angle plane. I like to use ready made stiff ones, like plane blades and gouges. Almost the whole of the inside is done with the rounded plane blade, with the recurve done almost entirely with the 1" gouge. Since the inside is entirely concave there isn't much use for a flat edge scraper. Both are very stiff, with a 20-22 degree edge ground on them. I do use the big gouge sometimes on the recurve to be sure everything is consistent. On the outside the straight plane blade is the workhorse, doing just about everything. I also use the rounded plane blade in the recurve area. The small scrapers, made out of shim stock, work right around the purfling. The tight one for the c-bouts, a flatter one for the u-bout, and the flattest for the l-bout. The other end on one of the shims is used on scrolls.

The scrapers blend in the divots made by the gouges. Many violin makers use sets of small brass planes with rounded soles to rough things in a little faster and smoother. I haven't bought a set of these yet. But I did see a cheap (inexpensive?) set from China online for $50 ($75 with shipping) on Ebay that might be worth looking into. For a machinist I am not a big tool nut, and outside of work I don't even use power tools. Smoothing in the curves is best done without a lot of light, but with it coming from the right angle. The scrapers are swung in long arcs, and the angle may have to shift as it goes along. The goal is to make every curve blend into the next.

1 comment:

  1. The cheap chinese fingerplanes are actually quite good and a set of four of those will cost the same amount as one Ibex fingerplane. Definitely worth the money.

    ReplyDelete