Acoustic Guitar Construction

am making this OM for my granddaughter who will be 18 next April and beginning college in the fall of 2022.
The Claro Walnut for this guitar I resawed from two book matched billets purchased about 4 years ago from Pine Creek Woods in Oregon. I got 4 guitar sets from these billets.

I had not bent this wood before. The only other walnut guitar I made, a Black Walnut OM back in 2012. That guitar was the last one I hand bent the sides on a pipe. After that I made my Fox style bender heated with light bulbs.

Since then I added a heating blanket and controller about 4 years ago. The first set of sides for this guitar I screwed up on in the bending. Too thick, no moisture, and too hot. So on the second set, I spritzed the sides, wrapped in foil, and kept the heat below 280 degrees and I got two near perfect bends with barely any spring back. No scortching, no cupping. I was very pleased. So I have an extra orphaned back set to be used for something else later on.

Anyway, what I've done this far is bend the sides, make the end and heel blocks and glue them in place. I am trying something new for me on the one. 5 of my guitars are in India and all suffer from the high humidity and heat fluctuations there. The pulling down of the top under the fretboard extension, and the rotating of the bridge. So this guitar may also end up in India after college, so I wanted to at least address the top under the fretboard. I am going to do my own version of a bolt down fretboard with a bold support underneath as part of the heel block.

It should not add very much weight but add much more support than just the transverse brace and tongue depressor brace that is traditional for this area of the top. I think I have it figured out, so we will see how it goes.

So the sides are sanded in the radius dish. I made my dish many years ago from MDF and it is two sided. 30' for the tops and 15' for the backs. I also flat sanded the top area from the waist to the heel block so this area will be almost totally flat. I will still use the transverse brace, but no tongue depressor brace. Next is to glue in the kerfing, but first I have to make the kerfing. That comes ne

So a few years ago I made my own kerfing with a couple of very simple jigs. I was pretty happy with the way it turned out. I had not made any since, but a few months ago Hibdon Hardwoods was selling kerfing stock; honduras mahogany in 5/16" thick, 3" wide and 32" long pieces. It was really a great price and you can get enough for one guitar from one piece. I think they were like $4 each, maybe $6 but with the cost of kerfing these days, it was a great way to go and it is fun to make if not a little tedious.

So I got enough made for Saturday for two guitars with more to make at a later date.

Here are a few pics of my set up. Rip the pieces into strips. They are 32" long but that is a bit hard to work with the way I'm making them so I cut these in half to 16" each. I use double sided tape to attach a strip the side of a flat a square board. There is a cut in the jig for the blade to ride in and this board also acts as a stop for the kerfing strip that is fed into the blade. There are marks on either side of the blade on that stop board to visually index the strip as it is moved for each successive cut. I think my cuts are 5/16" apart. This is a very simple process which with a little set up and careful cutting can come out near perfect. Then I take the kerfed strips to my drum sander. I have a simple jig that a strip sets in which with several passes with create a triangle shape to my kerfing. What I do is take my stack of kerfed strips, and work each on through before I lower the drum for the next pass. This is a bit time consuming, but gives a consistent size and shape to all the pieces, and really doesn't take a lot of time. A 16" length is a bit easier to work with. I like to spritz the strips with water and work them carefully to fit the sides, clamp them and let them dry. This helps them to not brake and they fit really well once you glue them in.

And finally I got the back plates glued up with a D-45 style back strip.
I think it will look nice with the walnut. They are .120" at this stage, I will take the back down to .100" in the drum sander after cutting out the shape.

Thank you for the detailed build blog! I have yet to make my own kerfed linings, I have made tentalones/peones for my flamenco guitars. I like your idea with the kerfed linings to make the jig for the sander. I have a jig much like it to run a rectangular strip of mahogany through the band saw and get two identical triangle stripes. I cut all the way through for peones. It looks like when you set up to you make a bunch of strips.

I have not cut my own kerfing but may now. I have some spanish cedar that has too many flaws for a neck. I always radius sand my top and back edges after the kerfing is installed. Thanks for the ideas.

What I do is get the sides radiused, then install the kerfing, and radius again, just down to the sides. This goes really fast with the little bit of material to take down.
Its just the way I've always done it.

Kevin, thanks for the build log. Always great to watch your progress.

Nice bending Kevin,
I find Walnut one of the easiest wood to work on. In hand it has little ring to it, but once in a guitar it does it's work astonishing. Keep on the good work Kev'.
Herman

After about 3 weeks of no activity I got a little bit done.
Center back strip is glued on made of redwood taken from left overs from a redwood top.
I also cut the braces for the back, just need to radius them, then I'll install them. I also started cleaning up and sanding the inside of the rims and kerfing to make it look smooth and pretty.
Still not sure if I'm going to put a spruce or redwood top on this guitar. I think I will glue up the redwood and see how I like it. It will be a 4 piece top from some premium old straight grain redwood I acquired a few years ago. The boards are only 5.75 inches wide so I use 4 pieces. The grain just blends in with the joints and the joints on the one I've done thus far is very strong. So I'll make that decision soon.