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About a year and a half ago I got the urge to build an archtop guitar. I ordered a couple sitka top sets and put them away and read everything I could from the GAL and ASIA and OLF forums and bought the Benedetto book and dvds.

Then I chickened out and proceeded to build a couple flat top guitars, several ukuleles and a dulcimer for other folks.

Some time in there I bought the Benedetto plans too and realized just how big those 17" guitars are. I kind of like smaller guitars, maybe because I play mandolin mostly. Anyway, I looked at my small jumbo plans and thought an archtop would look good with that profile. After reading and searching the web for what others were doing I figured it was worth trying. And if the sound isn't big enough I can always put a pickup on it.

A week or so ago I joined one of the sitka sets and used my small jumbo form to mark a profile. I didn't take any photos of that but it was pretty boring. Then I made a carving cradle like the one Benedetto has in the book and some arching templates, reduced in proportion to the new body size.(97% length wise, 92% for lower and upper bout)

I've been carving with a combination of a small Lie-nielsen plane, a block plane and a fish tail chisel. That's been quite a work out but I like it more than I thought I would. And I shaped the outer perimeter of the plate with a Wagner safe-t-planer like Benedetto shows. Though I have to state here that it is possible to hurt yourself with that tool. A previous project was dubbed "The Blood Uke" by it's new owner since I'd put so much of myself into it.

So... this is my project so far.

Hi, Raymond. Looks like you're off to a good start. I really dig archtops and I'll be watching your progress. A related suggestion for you: You might be able to save a couple of scrap off-cuts from that cherry board which you could use to make your own round-bottomed plane. I have just such a cherry plane that I made sometime back in the 80s. It's getting a little worn on the bottom (sole) but it's still a good cutter. Good luck with the guitar and keep the pictures coming.
Patrick

Hi Patrick. That's a great idea about the plane. I just so happen to have a small board already milled from the same group of trees that looks the right size.

I like the small lie-neilsen but it is slow going because it's so small. Though in some areas it's not small enough. My block plane works good for the outside arch, though I think I need to round over the edges of the blade because they did into the wood. But the bigger round bottom plane you suggest should make it a lot easier for the other side of the top.

Thanks again!

Yo, Raymond, you will definitely need a way to scoop out the insides of your top and back, and that's why I suggested making your own plane. You might prefer to just buy one, and there's nothing wrong with that option, either. But I find it soooooooo satisfying to make my own tools for certain purposes. There is nothing all that difficult about making a carving plane (or two or three, to different bottom radii). I am just encouraging you to set aside a couple of weekend afternoons for that purpose, and you can do it in between other tasks.
I probably don't need to tell you this, but I will write it for the benefit of the lurkers:
You would spend the first afternoon roughing out the two sides of your plane body or bodies, and you would glue them up. You would spend the second afternoon filing and sanding the bottoms of your planes, grinding your irons, fitting your wedges, etc. After dinner on the second afternoon (or the next weekend) you would be ready to start making shavings. What a GLORIOUS feeling it is to make shavings with a plane made by your own hands!

Go for it, Buddy!
Patrick

Well, this is what I put together yesterday afternoon. You're right Patrick, it is worth the effort and doesn't take much time, though I probably wouldn't have if you hadn't encouraged it. I'm already glad I started posting this build.

I dug out the Irving Sloan book and made this as close as I could to his example. I think I'll go back later and try out the design The Padma had posted on his archtop thread. They seem like they'd be easier to shape the throat opening.

I made this throat about 5/32 wide and it does well as a scrub plane. Next time I'll try to get that a little tighter or make an adjustable throat. I'm using a 1" Hock blade that I had that I re-shaped on my six inch grinder. At first it didn't work very well until I widened the bevel. Now it works better than any of my other planes on the inside arch. (the hock blade was from another wooden plane project that I never started)

Today I'm going back to cleaning up the outside arch.

I've been slowly whittling away at that top outside arch and I have it pretty close to where I want it before starting the inside. Here's a picture of where it's at today.

I found that due to the weather or removing wood or both, the top will warp slightly from time to time, like a potato chip. But if I just just flip it over on the carving cradle and go away for awhile, it relaxes and straightens back up. So, earlier in the week while waiting for the top to rest I started working on the back to make better use of my time before and after work.

Here are some pictures of what I did for milling the cherry for the back plate. My band saw is an old Craftsman 12" and will only re-saw about 7 1/4". So I picked an end of that big cherry board and cut a chunk out about 23" by 7 1/4" on my table saw. Then I used a 60 tooth ply-wood blade to score the center all around the edges to guide the re-sawing. The individual plates are just just shy of 7/8" thick after cleaning up on my thickness planer.

I also cut a center strip from the same section of the original board 1 1/2" wide and 7/8" thick. So at the end I have a back plate that's 16 " wide. Adding the center strip also moves a couple cracks out of the profile of the upper bout. Otherwise I'd have just glued smaller blocks on the wings of the lower bout. I considered just cutting off the cracks but that wouldn't have left me enough wood between the end of the board and some knots in the center of the board. It wound up being the same amount of work anyway.

Well...onward...

The past couple days I got a little time in to work on the back. I started by re-doing my arching templates. I had tried to make them out of masonite but my skills at the band saw are less than you'd expect at my age. So I just pasted the photocopies from the book to some thick card stock leftover from one of my kids' school projects, then cut them out with scissors and buffed the edges with fine sandpaper, like making paper models as a kid.

Then I drew contour lines on the back indexed at the neck end and tail end about 1 1/2 " per step. I just drew a free hand shape for each line that looked nice to me and roughly matched the profile. Then I set up my drill press and drilled, starting at the edge of the profile and the first inside line, as 3/8 inch and continued increasing the gap 1/8 inch for each contour line. The only problem I had was that my drill press isn't big enough to reach inner most line on the lower bout.

But that's ok, because after trying to carve that cherry I when back and terraced the top at each contour line with my wagner planer, roughly 1/8" at each step. That made it a lot easier and after knocking off the sharp edges with my block plane I started working over and around the curves which seemed to make it easier to control the arch side to side and front to back.

So lastly, I put the back plate aside and to revisit the top which was slightly uneven from side to side in both the lower and upper bout. Using the new planing technique I'd started on the back, I had the top evened out in just a couple minutes.

With that I had to clean up and get to work!

I had some extra time yesterday so kept at the back carving. This picture is about 1 hour's worth of work later than the last picture. I just kept shaving as evenly as possible with the block plane, round bottom block plane and chisels. This morning I used the wagner planer to take the outermost edge down to 5/16". No regrets so far.

Here's a picture of the state this morning and the way I used the wagner planer. I thought ahead enough to put some thin plywood behind the drill press to keep the chips under control. Also, I flipped my homemade table over and have it sticking out to support the top better.

I worked some on the outside arches of the top and back today and got them pretty close to what I want. The outside edge of both are at about 1/4" using the wagner planer. I'm thinking they may shift a little one way or the other after removing the material from the inside so want to leave room for adjustments.

So, I put together my drilling thickness jig made out of a couple wing nuts, washers and a 6" piece of threaded rod and drilled holes all around the inside so as to leave about 1/2" thickness. I drew a line about 1 1/2" inside of the perimeter so I wouldn't drill out that far but I didn't need to worry since at 1/2" I have to go pretty far towards the center anyway. I plan on getting the sides together with the linings and use them to mark a line of where to stay away from.

Then I spent about 1/2 hour planing the inside arch. This is going quicker than I thought all things considered. I'm switching between the wooden plane and the round bottom steel plane, both work well in their own way. The steel plane gets pretty hot quick. If I just had it I'd probably be taking more breaks.

All this took me a couple hours today, including staring into space thinking, vacuuming the chips and emptying my shop vac.

Hey, Raymond, you are doing great and I am watching your new posts avidly. Slow and steady wins the race every time! Just keep on keepin' on. Take it steady as you have done thus far. Keep taking breaks...as you said...to "stare into space". Pretty soon, you are going to have a real nice small archtop there. And I am eager to see it.

Patrick

I worked another hour over the last week and to both top and back down to about 3/8” thick. Still a ways to go but I'm pleased with the progress. One thing I noticed last week when working on the inside arch was that the weight of both the top and back dropped very quickly with each layer of wood. Also, I started noticing the sound of the planing lowering as I went. That was pretty cool.

I don’t know if it really means anything at this point, but just for fun I thumped the two plates and found a node where they each would ring. Then I held the plates 4 inches away from my guitar tuner and thumped them. The top consistently registered F4, though a little flat. The Back consistently registered D4, a little flat. The back sounds like it has more going on. That all kind of surprised me because I'd read that the digital tuners didn't work for that sort of thing. And honestly I've tried it on other instruments soundboards, like flat top guitars and ukes, and it never registered.

Anyway, this weekend I went ahead and re-sawed the sides, bent them and glued in the blocks and some side braces, like the Benedetto plans. The neck and tail blocks are some spanish cedar I had. And the neck block is for a bolt on neck since I’m planning on an oval(ish) sound hole.

I started laying out some 1/4 spruce to make some lining strips but got distracted with a broken water heater. So, I’m pretty much set up for when I can get back into it.

I took a few minutes here and there over this last week to work on the sides. Here are some pictures of my choice in linings. I had a bunch of 1/4 thick cutoffs from some sitka tops of other projects. It turned out that I had enough for all the linings and side braces.

I just eyeballed the kerfing on my tablesaw with my thin kerf plywood blade and ripped the sections to 1/2”. Then I fit them as best I could between the already glued in braces. Just before installing each section I beveled the inside edge with a plane. I have reverse kerfing and built small bridges to link the sections over the top of the braces. Since the bridge was so thick I trimmed them down with a sharp chisel and then sanded all the bracing and linings with 60 grit sandpaper to smooth out the edges.

Here also are some pictures of where I’m at on the top and back. The top is sanded with 80 grit sandpaper. I wanted to find the deeper gouges, and I have. The back is sanded on the outside but rough carved on the inside. My new sander broke down after about 30 minutes and I’ve sent for a replacement. That’s fine, I have plenty to do otherwise. While setting up for the pictures I found a good position for my lights and can see shadows of small flaws in the arch that I’m going to even out.

The top and back are about 9/32” thick right now. I tried the tapping again and noted that the top is ringing a slightly sharp D4 and the back is ringing at a perfect C4. I noticed that the node I’m holding is right about where an f-hole would go. I’m wondering if it helps to put the holes at nodes, like maybe it removes wood from an area that isn’t vibrating as much.

I spent a few hours yesterday scraping and sanding the top and back. My replacement sander had come UPS the night before and that made quick work of cleaning up the inside arch of the back. Though I have a hard time getting close into the inside upper bout of the plates because of the neck block area needing to remain flat. As I'm writing this down it occurs to me that I should just fasten a sacrificial block of wood onto that gluing surface that the sander can bump into.

While sanding the back I came across a small knot that popped out leaving hole about 1/16" deep on the inside surface. I had been keeping an eye on it so was careful not to let my vacuum suck up the center piece. So I got out some 5 min. epoxy and put the knot back in place with a toothpick. I haven't started sanding again but it looks pretty secure and is not visible from the outside.

The top on the other hand is moving right along. After hemming and hawing over what sound hole shapes I wanted I finally settled on some like the D'Aquisto Solo. I learned a couple things in the process. First that I was doing a pretty good job of carving the top evenly because the edge of the holes are right at 1/4" all the way around. Second is that those holes have a big effect on the tap tone. Before cutting the holes I noted a slightly flat C4 tap tone with two nodes almost directly in the middle of each of the two holes on a given side. Once I cut the holes the tone changed to a flat B4 while holding just to the outside of the holes.

Also, if I hold that bar between the two sound holes on either side the tap tone is just a dead thud. It would seem that leaving that piece in place may be a way of tuning the sound, like the small side tone bars on an x-braced flattop. But I could be wrong.

That was pretty exciting! I don't think I thought much about how the holes affected the vibration of the plate before, only the resonance of the body chamber. Good times!

It's looking very nice, Raymond. I'm curious about the height of your arching. The raking light in your photos makes the two plates look absolutely voluptuous. I'm not being critical. Just remarking. The symmetry looks real good and I think the sound holes will compliment the guitar very well. Looking forward to your next progress.
Patrick

Yep, it's coming along nicely Raymond. The lighting really accentuates the carving, particularly interiors. Always loved those D'Aquisto Solo soundholes. Looking forward to seeing her finished.

_________________
Dave
Milton, ON

Thanks Patrick and Dave. I'd looked around at smaller archtops and was drawn to the older L-4s. They seem to be curvy as well, though probably not so much as this.

Right now the top is just a hair under 1" from the bottom of the plate to the top at the bridge. The back is about 7/8" for the same measurement. I'd been going of the Benedetto arching from his book for a 17" guitar as a rough guide. I reduced the measurements from side to side to fit 15 1/2" but hadn't reduced the height of the arch. The back is so much lower only because that's maximum height of the wood I'm using. I expect both top and back will wind up a bit lower from final sanding.

Excellent workmanship and documentation, Raymond!
I`ve been kicking an SJ archtop around my head for some time now, but you beat me to it.
How high is the arch on your top?
And, did you put a cleat or a strap accross that georgious sound port (in the center section)?
I`m kicking my own arse for not looking into this section of our community now.
Keep at it, dude!

Coe Franklin

_________________
Give me 50 cents worth of regular.
Check my oil too, if you don`t mind,,,

Thanks Coe. Yeah I thought the SJ should be a good size, and it saved some time because I already had the body mold.

The top arch is 1" from the bottom of the plate to top of the arch.

I haven't done any support around the sound port yet. Thanks for pointing that out. and I hadn't considered needing something in that section, only at the ends. And I have the Siminoff book on mandolin construction so was considering doing the gauze/titebond thing around the holds. But it seems like it might not be enough.

After finishing scraping and sanding through March, I finally got to fit the braces.

I also got the top onto the body. I need more deep clamps but the weight set on the melamine board worked pretty good. It seems pretty solid.

And I also did the initial neck construction. To make use of the cherry I opted for a stacked heel. Then I did a birds beak neck joint because it's fun. I bought a two way truss rod and mounted it for adjustment at the body end, in a hole underneath the extension.

I've been pretty busy with other things since my last post so haven't made a lot of progress. But I'm pleased with what I've done so far. Here are some pictures of slotting and tapering the fretboard and gluing it onto the neck. Then there is the picture of all the pieces in their current state.

So my next step was to glue the headstock onto the neck, glue on an ebony headstock plate, shape the headstock and drill holes for the tuners. I also drilled three decorative holes in the headstock. I was surprised at how much lighter the neck feels after removing that wood from the headstock.

For the fretboard I splurged on an ebony bass size fretboard from LMII. That way I have enough wood for the fretboard, a matching pick guard and some strips I'll use on other projects. After cutting down the fretboard, keeping the profile square, I slotted it on my table saw. I was going to just measure and mark the fret positions like I've been doing, but I'm planning on building a bass for a friend this fall so decided to go ahead and buy the 30" and 34" bass scale fret slotting template. Then I started slotting at the third fret on the 30" scale as the nut position and now have a 25.227" scale, just a little longer than the original 25" scale I planned. That is if my math is correct, if not then all my other instruments are off too and nobody is noticing. After slotting I glued the fretboard onto the neck then shaped the radius with a Stewmac 12" radius block and 80 grit sand paper, checking with a straight edge to be sure there were no humps or dips along the length of the fretboard face. I finished up by sanding with 120, 220 and 400 grit sandpaper.

I also bought myself the nice fret end cutters and a hammer, two things I've been making due without for a couple years. I used a combination of the hammer, the radius block and the fret press caul in my drill press to install the frets. I hammered in the frets then clamped with the radius block and wicked (sp?) CA glue into the end of the slots. After that I used the drill press to seat a couple frets better and wicked more CA. I also saw I had chipped the ebony at the edge of one fret slot when hammering in the frets a little to hard. Some ebony dust leftover from sanding and a little CA glue filled and hid that nicely.

Today I'm going to try shaping the neck in between chores.

All last week I shaped the neck and fit it to the body. It took quite a while using pretty much the techniques shown in the Benedetto book, fitting then trimming under the fretboard extension. Except the neck is a bolt on and I mounted it before attaching the back. I didn't want to mess with the extended allen wrench idea until I have to and it made it easier to get the barrel bolts aligned with the back off.

After mounting the neck today I spent an hour with my orbital sander working on the back. Once I got it in the ballpark of 3/16 and pretty flexible I sealed the inside surface with a little wipe on poly and glued it onto the sides.

Having the neck on made it a bit harder to trim the excess over hang of the back and sand the sides but even so it only took a couple hours, with interruptions. So far the guitar seems pretty close to the same weight as a Taylor 12 string I have. When I tap on the top plate the back vibrates quite a bit and it has a nice tone.

Now I have the guitar tucked away in the closet while I work on the tailpiece bridge and pick guard while I work up the courage to carve the recurve. Cheers!

I spent a good portion of the last couple weeks trying to come up with a design and shaping the tailpiece. I had purchased an ebony blank from LMI that turned out to be much thicker and wider than I needed. So I was able to get a bridge out of it as well. But I just wasn't happy with the tailpiece I came up with got an idea of a laminate of cherry and ebony that complemented the headstock design I'd chosen. So I fabricated the tailpiece in the pictures below.

Then also in the middle of making the bridge I dropped one of the knurled wheels down a heater duct. So I went to the LMI website to order another set. This turned out to be harder than I expected because I needed to buy enough to justify shipping and for the first time I can remember I simply didn't need anything else. So I just got some supplies and some stuff for future projects.

But anyway this weekend I scraped the recurve, leveled the frets, shaped a pick guard, fit the pickup, inlayed a piece of ebony into the top for the tailpiece cable to ride on, and drilled all the holes for the various hardware. Then I sanded the body to 150 grit, wiped down with mineral spirits then sanded again until I didn't see anymore scratches or gouges anywhere.

The pictures here are after wiping down with mineral spirits again. I'm debating my options for a finish so will spend some time polishing the ebony fittings when I have time over the coming week.

Cheers!

Yo, Raymond,
I checked in earlier and told you how much I've been enjoying this project. I was excited a moment ago when I saw that you had posted updates. While quickly scrolling through the most recent page of posts, I saw your drilled out headstock and the thought that immediately went through my mind was something like: "Hmmmmmmmmm.........." But then I saw the pics with the neck mounted, the drilled tailpiece, etc. Then my thought was: "I'm being hasty." That design concept is growing on me rapidly and I think it might prove to be a very satisfying compliment to the sound holes. I liked your guitar at the outset and I'm liking it more all the time. Keep the posts coming!

Patrick