Couple of wood questions from first timer

[Greg McKnight]

I'm in the planning and procuring stage of my first archtop build and have a couple of questions.

First, I have a nice piece of black walnut I want to use for the back but I don't know if it will be wide enough for a 17" body. I know, so make a 16" body Greg. Well, that is a possibility but I wanted to stick to the Benedetto plans as closely as possible since it's my first archtop. Is there any harm in using three pieces for the back? I'm assuming there isn't but I haven't seen or heard of it done much if any. I thought a strip down the middle maybe 2 or 3 inches wide could work, either the same width or slightly tapered like a Martin D-35 back looks (not as wide as a D-35 though).

Also, I'm wondering if there is any good way to join pieces of side wood that would be stable? What I mean is, can a couple of pieces be glued together to give me a 35" length for a side? A scarf joint perhaps? Assuming the extreme heat required to bend a side, the gluing of the two pieced would have to be done after the wood is bent. Is it possible you think?

Thanks for any advice from your experiences. I'm sure it won't be the last time I ask .

[Michael Lewis]

You can do as many (factories included) have done and glue "ears" on the edges of the back plate to make up the full width. This material can easily come from the trimmings of the upper bout, so the wood should be a good match. I think this is a much better solution to your 'problem'.

You don't need 35" for sides, though it is nice to have the extra length if bending on a hot iron, but if you are bending on a form or Fox style bender you can use much shorter wood. 32" should provide enough length that you will trim each end to fit your form. Don't piece together sides, they already have enough stresses going on. Walnut is not difficult to find, so get some that you can just move ahead and make your guitar.

[Greg McKnight]

Thanks for the advice Michael.

If I'm going to come up short on the back width, it will be barely short. And I do have a piece of wood that's a lot thicker than I'll need for the back pieces, so I should be able to find a match for some slim outside ears like you suggest.

Unfortunately I don't have any walnut to match the back wood, which is really dark. But like you said, walnut isn't so hard to find. It's hard to find side wood already cut without a matching acoustic back though. I'll just have to cut my own from a larger piece.

[Patrick Hanna]

Greg, hang on there, my friend.

In all probability, you DO have enough back wood to match things up for a "winged", 4-piece back. Maybe you just haven't realized it. Chances are excellent that you can get this wood from the sawn out waste in your upper bout and waist areas and glue it to your lower bouts on either side. That's what I did. Benedetto demonstrates doing this in his video/DVD series, too. He usually sunbursts those backs to hide the joint.

Here's a picture of an arch top walnut back, prior to and after finishing. (I attached the pictures in reverse order, but you'l figure it out.) If you look closely in the widest part of the lower bout, you'll see where I winged in some wood from the waist. I did that on both sides. I did it on one side of the top, too. Under filler, stain, and finish, the color variation all blended together in a way that looked pretty natural.

[Greg McKnight]

Hey Patrick, you're guitar looks great! You're right, that does blend very well. Don't you just love the look of walnut, especially when clear coated? I've used it in a couple of builds: the neck on a mahogany electric, the back and laminate neck of a Ric-type 12-string, and the same in a Les Paul style guitar. Great wood. How does it sound in that archtop btw?

[Patrick Hanna]

Hi, Greg,
Thanks for the compliment. My walnut archtop is a very nice, mellow instrument acoustically. I often play it unplugged. Obviously, you don't see the front in those pictures, but it has a suspended pickup attached to the fingerboard extension. Just a volume control, mounted in the finger rest. It sounds excellent plugged in, too. Walnut makes nice instruments, even if it's somewhat non-traditional for arch tops. I've seen a number of arch tops with a center piece added to widen the back. Those can be very nice, too. Whether you make yours that way or "wing" it, you'll be fine. I think it's largely a cosmetic choice. However, if you wing your back with off cuts from the waist, you can save that center piece for another project. Best of luck with it.

[Mark Langner]

Ditto all the comments about using some cutoff material from the upper bout to widen the lower bout. I have also made a couple instruments with three-piece backs (and a top in one case), and you can do it for decorative effect. Here's one where the wonderful "curly" cherry I had was not wide enough for a two-piece back, so I used a walnut center section (with a walnut neck) to make it look like a "neck-through".

[Greg McKnight]

^Wow, that's a beauty Mark! How does the cherry sound as a back wood btw? And are the sides cherry too? If you have any more pics or a link to a build thread, that would be great too. (I don't ask for much, do I?)

[Mark Langner]

Greg, With very limited building experience (14 and counting), I'm not sure I can isolate the sound of the wood as opposed to all the other variables I have only tenuous grasp of. That said, I have built two cherry instruments, and both are a little more bright-sounding than most others I have made. "Bright" is an awfully short and inadequate description - there is a recognizable similarity between the two (to my ears), but I don't have other words for it. They are both different from anything else I have built, but not grossly so.

The sides of this one are walnut.

I have been meaning to take a whole set of pics of this one and post. It was pretty much finished more that a year ago. Build pics I have never done. I'll just say it is pretty standard Benedetto construction, aside from the sound holes, whose shape I have evolved over several years.

[Greg McKnight]

Anyone had any problems with using flatsawn wood on their backs? Does it hold up well over time, and would a cross brace or two on the back help at all?

[Michael Lewis]

Flatsawn maple is the norm for the industry. Birds eye maple is a flatsawn figure, and shows up as pin knots in vertical grain. Quilt maple is also a flat sawn figure, and can show up as irregular curl if quartered. Maple grows with a darker wood in the heart, and typically is cut to avoid the dark wood. This pretty much dictates that it is flat sawn to get boards with any decent width. It takes a huge tree to get quartered wood for a guitar back, but it happens from time to time.

Flatsawn wood is not quite as stable as quartered wood, meaning that it changes size a bit more than quartered wood with big humidity changes. It has been used for instrument backs for many years and no braces needed for archtops, as the arching is the structure.

[Greg McKnight]

Thanks for the reply Michael. I plan on using flatsawn walnut for the back of mine. Just got the spruce top wood a couple days ago and I'm looking forward to carving.

[Alan Carruth]

If you lok at the properties of different woods, black walnut comes in pretty close to soft (European) maple. I've used walnut fo archtops and fiddles for years, and find it's a good replacement for maple. Cherry is a bit harder and denser in general, more like a hard maple. Walnut is also a very stable wood, and works well flat cut.

[Kerry Werry]

Ha Alan good to hear this, I'm starting my first Archtop this weekend and will be using some nice black walnut for the back & sides.. I've built about a 1/2 dozen flatops on my own but getting help from an established luthier for the archtop...
Best sounding guitar I've done so far was walnut & sitka..

Kerry

If you lok at the properties of different woods, black walnut comes in pretty close to soft (European) maple. I've used walnut fo archtops and fiddles for years, and find it's a good replacement for maple. Cherry is a bit harder and denser in general, more like a hard maple. Walnut is also a very stable wood, and works well flat cut.

[Jason Rodgers]

If you lok at the properties of different woods, black walnut comes in pretty close to soft (European) maple. I've used walnut fo archtops and fiddles for years, and find it's a good replacement for maple. Cherry is a bit harder and denser in general, more like a hard maple. Walnut is also a very stable wood, and works well flat cut.

I bought a nice pile of black walnut at a neighborhood estate sale - probably cut in the neighborhood and air dried for a couple decades in this old guy's basement - that is mostly rift swan, so this is good to hear. From the little bit I've played with, the density is all over the place, from punky sapwood that suffered bug damage, to typical, to very hard. There's a 5/4 piece about 12"x16" that I'm cleaning up right now for a project with an area that's so hard, a sharp plane leaves a polished surface!