Thickness planing sides prior to bending

Construction and repair of Classical Guitar and related instruments
geo-co

Thickness planing sides prior to bending

Post by geo-co » Fri Oct 27, 2006 9:13 pm

Hello - I'm new to luthier'ing (sp?) and I have a question as to why all the books I have looked at and the video that came with my LMI kit recommend the "safety plane". for thicknessing the sides prior to bending. My question to the group is would a reasonably tuned Delta 12" surface planer and some final scraping do the trick assuming I don't try to take off to much with each pass? BTW, I have Indian Rosewood sides and back.

Thanks,
Geo.

Pepe Vergara

Post by Pepe Vergara » Fri Oct 27, 2006 11:29 pm

What about the regular planer? the hand planer?

geo-co

Post by geo-co » Sat Oct 28, 2006 4:42 am

pepe wrote:What about the regular planer? the hand planer?
I did that with the neck and head, it was fun but I'm a bit concerned that the tollerance for sides are more exacting. My consistency across the larger surface area is not as good as I wish it could be... Maybe just take it down with a thickness planer to within a mm and then plane it the rest of the way.

Thanks for your input!

MarkJ

Post by MarkJ » Sun Oct 29, 2006 5:19 pm

I would not use a power planer for the sides, top or back. I have used hand planes, like a #4 Stanley, and a scraper, but it is hard work and unforgiving if you take off too much. I now use a thickness sander and I am convined that it is the best way to get the thickness to within 0.2 mm or so of where you want it. I finish with a few strokes of a well burnished scraper.

If you have a cabinet shop nearby they will probably rent you an hour of time on their machine for 20 bucks or so. I take the sides down to about 0.085 (2.2 mm) on the thickness sander for Indian or Madasgascar Rosewood ( I then cut off binding strips from the sides). I take the back to 0.080 and then a few strokes with the scraper on the show side. Starting top thickenss varies with the material stiffness of each top, but generally 3 mm or so for most Engelmann, 2.7 or so for German, 3.2 or so for cedar - then you have to do additional thinning with a scraper and sandpaper from about the end of the bridge to the the lining edge on the side and the tailblock of course.

Pepe Vergara

Post by Pepe Vergara » Sun Oct 29, 2006 6:32 pm

MarkJ wrote: ... cabinet shop nearby they will probably rent you an hour of time on their machine for 20 bucks or so...
Lucky you. It is about $80/hr in my area!

geo-co

Post by geo-co » Tue Nov 07, 2006 4:51 pm

pepe wrote:What about the regular planer? the hand planer?
Well, I got off my butt and I got a nice wooden smoothing plane ($35 on sale). After an hour of effort I had a properly thicknessed set of sides.

Thanks for the motivation!

Geo.

Return to “Luthiers”