Sunday, March 29, 2015

Making a Three Piece Guitar Back, or, When You Choose the Wrong Wood

It is important to make a nicely fitted joint.

Dean Kimball, Construction the Mountain Dulcimer, 1975


I picked up a back and side set of "wild grown" east Indian rosewood from the Woodcraft Store in Loveland, Colorado a little over a year ago. I remember that Woodcraft had advertised this wood on their website then and by the time I got around to ordering it they had sold out. I think it sold for $49.99 a set and I bought this set for $70.




Originally, I had planned to make with this rosewood was going to be simply fitted with bubinga bindings, nothing fancy, but after glueing in a bit of bubinga between the two back halves I realized my mistake. The reddish bubinga disappeared in the field of browns and olive greens.




What to do!

First thing I did was to cut the back apart with knife and straight edge, then I spent some time going through my wood cache.

Curly maple was too showy and I had already fitted out the last two guitars in maple; California laurel didn't look right; walnut, nope; another piece of rosewood?




Then I found some sapele. It fits well with the rosewood and compliments the western red cedar top that will go on this guitar.

The no.7 Stanley plane in this photo is now one of my favorite planes, it is remarkable how easily you can adjust the blade depth on these vintage planes when you use the original blade and there is very little backlash.




This jointing operation was a little tricky, I didn't have much excess wood in which to place indexing pins. I used an original hole for one pin and then I had to use a brass brad for the lower bout. Sorry about the fuzzy photo!




Ah, the glue up! White/black purflings border the sapele insert and I used Lee Valley High Tack Fish glue to glue the whole thing together.




The back after clean up.

It's always nice when you can fix a mistake and make everything look better!



Here's a YouTube of the wonderful guitarist, David Russell!


Tuesday, March 24, 2015

Junk Sitka Spruce

It seems but natural and reasonable that the woodworker should have at least an elementary knowledge and understanding of "wood", the principal material with which he works.

Herman Hjorth, Principles of Woodworking, 1930



I purchased several sticks of Sitka spruce bracing material six months ago from a well known lutherie supply (which will remain nameless, I still need to buy tonewood from them), I used one blank to make braces for one guitar and I had no problems working it.



Prep work started on the "conservatory model" - a high quality, lower cost guitar aimed at students who can't afford a $3,500 guitar - with jointing, assembling the cedar top and installing a rosette, making the neck, etc., and splitting out the Sitka spruce braces.

In the above photo you can see what happened to a brace when I gently (yes, I said gently) flexed it, it broke!

The reason it broke under light pressure is because the early growth rings are much wider than the late growth rings. I noticed this when I received the wood, but figured, hey, it's Sitka spruce it should be tough.


I was wrong. Here you can see how wide the growth rings are, this wood isn't even suitable for the beefier transverse braces that go above and below the sound hole, it flexes too much.




Here is a piece of old growth Douglas fir that I've been hoarding for fifteen years, you can see how tight the growth rings are.

The piece split well and is very light. I used Douglas fir for guitar bracing when I first started on this adventure that is lutherie, it's terribly strong, though can be a little heavy. Several guitar makers told me I was crazy to use it because it is too heavy.

Not all Douglass fir is "too heavy", the braces that I split out were as light as the Sitka spruce. Yes, I weighed them!






So once again I am back using Douglas fir, this time for braces on a Miguel Rodriguez style guitar.

I grew up with Douglas fir because it was a tree that lived in my backyard which was the million acre wood known as Lassen National Forest. I know how Douglas fir responds to an axe, a plane and a nail. Sitka spruce doesn't grow where the Cascade Mountains buried the Sierra Nevada, I didn't get a chance to work with until I was an adult.

Sometimes it isn't a bad thing to stick with something familiar.

Monday, March 23, 2015

More Wooden Straightedges

A straightedge of convenient size should be made for ordinary use, and almost any kind of well-seasoned wood is suitable, mahogany and walnut being usually favored...

Bernard E. Jones, The Complete Woodworker, 190?




I posted else where on this blog about making straight edges from one of my favorite woods, California laurel.

My mistake was making only one straight edge from the laurel, I should have made two.

Why?

Two straight edges the same length are easier to check for straightness, you just put the edges together and look for a gap, then you can plane the edge straight again.

I realized I need an 18 inch straight edge, instead of a 17 inch straight edge, to check the flatness of the fret board that I recently put on a copy of a 1930 Santos Hernandez guitar.


My stock of California Laurel is getting low, what I have is reserved for another blanca guitar, I have some nice eastern black walnut on hand so it was off to the table saw.

I ripped out two slats, clamped them together and jointed the edges. I didn't taper the pieces as per instructions given by Jones in the aforementioned book (or what some former editor[s] of a woodworking magazine says you are supposed to do), I left them chunky so when I go to re-shoot the edges all I have to do is butt the ends up against the bench stop. I don't have to chuck them into Shop Fox vise, just fix them and go back to work.

I do plan on beveling the edges as Jones suggests doing, those edges give a better reading when placed on the surface that is being observed.




Ah, just what I needed!

The guitar is now fretted and after I run some errands tomorrow morning, I get down to the business of carving the neck.

Once that task is completed I will then have three guitars - a Torres FE19 guitar, a 1961 Hernandez y Aguado guitar and this Santos - to French polish!

Stay tuned, I will be posting photos of the latest 1930 Santos Hernandez style guitar!

Saturday, March 7, 2015

Stanley No.101 "Toy" Block Plane

Fine guitars can be made without any power equipment.

Irving Sloane, Classic Guitar Construction, 1966



The other day I needed to finish shaping the braces on the back of the latest guitar, a copy of a 1930 Santos Hernandez guitar. I didn't want to fuss with my No.60 1/2 block plane...



so I pulled out this little number. I bought it about two years ago at a meeting of the Rocky Mountain Tool Collectors for $5 and it's been sitting on the shelf until this week.





I locked the blade in the sharpening jig and took it to a diamond stone, didn't take long to get a good edge on it.





I flattened the back using "the ruler method", the blade took on a nice polish...





and I swiped the sole across the stone a few times. Still needs a bit of work, but really, I'm using this plane to shape braces not a table top.

If it only had an adjustable mouth...


I know you can find these planes used for around $25 on the Internet, pick one up and give it a try, it's a fun little plane!

What a Concert Classical Guitarist Says About My Guitars

  I have had the pleasure of playing the magnificent guitars made by the luthier Wilson Burnham. The first impression that one perceives is ...