Prototype Archtop Build

[Geoff St. Germaine]

I couldn't tell you the exact mill thickness. The finishing of the interior is as recommended and directed by Benedetto. Since the three coats were sprayed onto unsealed wood, it didn't build very much at all. In fact, even though it was a gloss product it didn't get to anything beyond perhaps semi-gloss.

Pros, I've certainly learned the downfall of impatience. Taking twice as long to setup properly undoubtedly saves time over rushing in the long run. Fixing mistakes or redoing work takes up a ton of time.

[Menapia]

Love'n this build ,keep the pix coming Geoff.

[Juntunen Guitars]

I couldn't tell you the exact mill thickness. The finishing of the interior is as recommended and directed by Benedetto. Since the three coats were sprayed onto unsealed wood, it didn't build very much at all. In fact, even though it was a gloss product it didn't get to anything beyond perhaps semi-gloss.

Pros, I've certainly learned the downfall of impatience. Taking twice as long to setup properly undoubtedly saves time over rushing in the long run. Fixing mistakes or redoing work takes up a ton of time.

I didn't realize Benedetto finished the interior of his guitars. Even more reason for me to go buy his book I think.

[Prostheta]

It stands to reason, the same one as to why you veneer both sides of a board. Sealing one side will encourage uneven expansion and contraction, so lacquering the inside of an instrument even a small amount makes sense.

[Pestvic]

Holy crap this is such awesome work! I'm scared to dive into acoustic stuff haha. I'll watch this thread

[Geoff St. Germaine]

Thanks a lot, Pestvic... and Menapia, I'll post updates later this evening.

Pros, exactly. Benedetto's book recommends exactly that for the headstock. The idea with the very thin inside finish is to slow absorption or loss of moisture enough to prevent cracking in the case that the instrument is exposed to very dry or (to a lesser extent) very humid environments.

[Geoff St. Germaine]

As promised, here's an update.Looking through my last posts, I've actually made a good amount of progress on the neck.The headstock ears were glued on. In hindsight, I should have done this after gluing on the fretboard extension and routing the channels for the neck reinforcement. I normally use a router table fence for these channels, so once the headstock ears were on I no longer had a surface to properly run against the fence.Here are the headstock ears in clamps.I then glued the fretboard extension on. Nothing fancy here. I used a router with a template bit to cut the 3/16" x 5/8" rabbet for the 5" long extension.Here's the neck with the fretboard extension and headstock ears.I glued in the two 1/8" x 3/8" carbon fiber bars using System Three Clear Coat epoxy. The channels weren't quite as nice as I'd have liked, but the epoxy does a good job of filling those minor wavers in the channel.

Edited February 12, 2013 by Geoff St. Germaine

[Geoff St. Germaine]

Next I moved on to the fretboard. This one's getting MOP block inlays. The next archtop is getting gold MOP blocks, so I did all of the routing and installation at once. I used a Dremel in the StewMac precision router base to route the inlays. I lined up the inlays on the fretboards and scribed around them to define my routing line. I then routed each cavity to hold the inlay with the center of the inlay very close to flush with the fretboard (the board is already radiused, so that adds some complication).

The inlays were glued in with more of the System Three epoxy but with both ebony dust and black dye to make the epoxy black and hopefully with a very similar sheen to the ebony wood.

I'll wait for a day or so before sanding the inlays flush with a radiused sanding block.

Finally, I started cutting out the headstock inlays. I was going to put my last name on it, but St. Germaine is a lot of sawing. GSG are my initials, and a lot less work with the jeweler's saw. Here's the first one (it's the back, as the front is covered in glued on paper that I used as the template and which won't come off until the inlay is installed)..

Edited February 12, 2013 by Geoff St. Germaine

[Geoff St. Germaine]

It's time for an update.

I finished sanding the inlayed fretboard down. Overall I'm very happy with the result. On the board with white MOP blocks, the black dye seems to have penetrated the shell in a couple of areas, most noticeably on the inlay of the 1st fret. While the dye penetration appears uniform and is not a huge issue, I will have to come up with either a different manner of glueing the inlay in, or some way of sealing the shell to prevent this. Interestingly there was no dye penetration of the gold shell. Weird.

Next I turned my attention to the headstock. I glued in a "fretboard" stop, as Benedetto calls it, which is a piece of wood glued at the headstock/fretboard surface intersection to bring the level of the headstock overlay up so that the binding for headstock and fretboard line up. I wasn't able to get it to work exactly, as I would have had to move the fretboard further down the neck, which would have moved the 14th fret past the body join. That goes into the notes for the next two. I didn't get a picture of that.

Next I glued on the headstock overlay. I cut a 17 degree angle into the edge of the headstock so it would make a 90 degree angle to the fretboard surface. I then rough cut the headstock to shape and the attached the headstock template to route it to shape.

I routed it to shape with a top bearing flush trim but when DISASTER STRUCK!

The short grain near on the sharp edges tore out. Fortunate I had off cuts from the headstock that I was able to use to make a patch piece. I cut the headstock surface flat with a fret saw and planed the headstock off cut true.

Overall the repair looks ok, so that's done.

Next I routed the headstock for the binding and for the inlay. I decided to try CA glue and dust instead of the dyed ebony. It seems to work well.

Next I tapered the fretboard. I have a jig that I can use to route straight lines with a flush trim router, which I used to trim each side of the fretboard.

I've been working on a commissioned neck build that is close to wrapping up, so I should be able to get back up to speed in terms of progress.

[Geoff St. Germaine]

The next order of business was to get the headstock bound. I used a heat gun to heat the binding to get it bent for some of the tighter curves. I used modeler's cement to glue it on and binding tape to hold it in place.

Once that was all attached I scraped it flush. Overall I'm pretty happy with my first inlay.

Next I glued on the tapered fretboard. I kept it aligned using two finishing nails that I'd drilled through the first and last fret slot to mount. It kept things aligned perfectly during the glue up.

Once the glue was dried I installed the fretboard binding. Nothing really fancy here. I used muttered joints at the end of the fretboard. Since it was straight runs the glue up and taping was very straightforward.

[Geoff St. Germaine]

I installed the frets. This was pretty straight forward. I cut the frets to size and nipped the tang off of the ends with a tang nipper. It was then a matter if simply hammering them in place. I used a piece of the neck cutoff as a support to hammer against for the lower 12 frets.

I had to make sure any adhesive that had seeped into the fret slots from binding was cleaned out. I did this with an Xacto knife.

On the first fret it seemed like it was harder to hammer in than I was used to. I realized I hadn't filed a chamfer into the top of the fret slot with a needle file as I normally do. Doing the first one without this and the rest with really illustrated to me how much easier the fretting goes with this chamfer.

Here's the setup with my tools and fretwire. It's LMII FW74, 18% silver/nickel wire.

Fret cut to size:

Starting the installation:

All installed:

Ends trimmed:

I hope to get the neck shaped this weekend. I'm away for 2 weeks after Sunday, so hopefully I'll get that done. After that I'll start fitting the fretboard extension to the top.

[shad peters]

I am loving this build! can't wait to see it complete

[Geoff St. Germaine]

Thanks a lot, Shad! I've looked at many of your build threads here and at MyLesPaul and learned a lot and taken a lot of inspiration from your work.

[shad peters]

Thanks a lot, Shad! I've looked at many of your build threads here and at MyLesPaul and learned a lot and taken a lot of inspiration from your work.

I believe there has been some sort of mistake, you clearly have me confused with someone who knows what they are doing lol.

[Geoff St. Germaine]

Ha! Your buckeye burl vixen is outstanding!

[Dean]

I am digging this build , looked good.

[Geoff St. Germaine]

Thanks, Dean!

[Geoff St. Germaine]

This will be the last update as I'm going on a business trip for the next 2 weeks.

I have carved the neck. I still need to do some final shaping of the heel and the bottom of the fretboard extension.

I carved two areas of the neck, near the nut and heel with a surform and rasp and then connected the two points. Final shaping was done with a spokeshave.

I test fit the neck in order to get an idea of the shaping required for the fretboard extension and the alignment of the neck wrt the body centerline. I've marked the fretboard extension outline. It promises to be a tedious task!

So that's where it is for now.

I have been considering adding two veneers to the back of the headstock, a maple inner and a black dyed outer veneer. This supposedly would reduce the chance of the headstock warping as a result of the ebony headstock overlay. Does anyone have any thoughts?

[Juntunen Guitars]

I have been considering adding two veneers to the back of the headstock, a maple inner and a black dyed outer veneer. This supposedly would reduce the chance of the headstock warping as a result of the ebony headstock overlay. Does anyone have any thoughts?

I wouldn't worry about it unless you want to add them. I don't think the ebony cap will warp the headstock but it's up too you. If you do I'd add another ebony cap instead of a black dyed one but that's just me.

[Geoff St. Germaine]

Yeah, I'm gonna skip the additional veneer. Thanks for the input!

[Geoff St. Germaine]

I decided to take some time to work on some of the small bits - bridge, tailpiece and fingerrest.

The bridge is right out of Benedetto's book. Two piece ebony with knurled adjustment posts. I simply cut the two pieces to the correct size and shaped them using files, chisels and a spindle sander. It' rough fit to the body top. I'll sand it for a perfect for once the body is finished. The tailpiece was made at the same time. Again, right from the Benedetto book, but with a slightly different profile. The string anchors were drilled with a drill press and the slots added with a Dremel in the Stewmac precision base.

I also put the magnet into the truss rod cover. It pulls against the truss rod nut to hold it in place. So far it seems to work, but the nut needs to be installe before it will rest in proper alignment.

The fingerrest was cut from an ebony fretboard blank and bound with white plastic to match the other binding. The fingerrest is mounted with two screws to the side of the neck through an ebony block attached on the underside. It is slightly angle to match the pickup and sits parallel to the body sides, 3/32" below the fretboard surface.

Here's a mockup with all the bits:

[Dean]

sweet,Classy,and Beautiful....almost time to wake her up.

[maull]

want.

[Workingman]

Nice!

[Geoff St. Germaine]

Thanks guys, I am very happy with how it's coming together.

I glue in the neck. Shaping the neck extension was tedious to say the least. I used chisels to get it roughly to shape. After that, I placed sandpaper between the top and underside of the fretboard extension and pulled it out until I got a tight fit.

I applied glue only to the inside of the joint and a bead to the fretboard extension, as described in the Benedetto book. A single clamp with a couple of cauls held the neck in place.

I am now into the tedious process of grain filling the walnut. One of the reasons I'm excited to work with flamed maple on the two archtops I'm following with is that the wood has closed pores. To get a glassy appearance the walnut is going to need substantial filling. I sprayed a sealer coat on the walnut and I'm in the process of filling the pores with CA.

Here's the walnut with some sealer. My intent was to keep the cost down, which is why I went with a plain, slip matched 3 piece back and plain sides. Here's a shot:

Edited March 15, 2013 by Geoff St. Germaine