I've finished the braces for the top.

I was originally going to use a forward-shifted X-brace. Then I decided to use the Ovation LX brace pattern.

But when I started laying out the braces I found that the pre-made dreadnaught braces I bought from StewMac wouldn't fit the LX pattern. They did fit the forward-shifted pattern with a few minor mods to the length, so that's what you see below. For those who are curious about the difference between a standard X-brace pattern and a forward X-brace pattern, StewMac has a page that explains both. See: Banjo Killer? The scoop on forward X bracing for greater guitar volume.

I'm also including the LX brace photo I posted previously for comparison. The primary difference between the Ovation LX braces and the braces I'm using is that while the Ovation braces are scalloped, they are square in cross-section. The braces I'm using are scalloped and tapered to a parabolic cross-section.

I laid out the pattern on my cardboard template for sizing, spacing, etc. I was going to use a cloth patch over the X braces, but after some thought I've decided to make an X-shaped patch out of birch ply and notch the tops of the braces, like what Ovation does on their LX braces.

Once that's done, I'm going to draw the pattern onto the back of my top wood, then start gluing tomorrow. Progress pics to follow.

I glued the braces to the top wood today.

First, get the glue pot started.

Set up the GoBar deck.

Tape visqueen to the base to prevent any accidental gluing of the top to the base.

Clamp the top wood temporarily. These will get removed as I add braces.

I figured it would be best to work from the center outwards. As I add more and more GoBars, they would get in the way of later clamping.

First, the X braces.

Rosewood bridge plate.

Tone bars.

Treble finger braces.

Bass finger braces.

Reinforcement strips.

Transverse brace.

Lastly, the reinforcement strip for the X braces. I was going to use a x-shaped plywood piece, but I did a little reading on the subject and a lot of builders just use a simple strip like this. Once the glue has dried, I'll shape it to match the cross-section of the braces.

Progress continues. The reason for the spaces of time between my posts is that I need to gather either tools, materials or both.

As I noted previously, the fretboard extension is warped downward which interferes with taking the braced top in and out. I knew this was going to cause problems when I get ready to glue the top into place and I would run the risk of scratching the top.

After a little thought, I built a tool that pulls the extension up out of the way. Now I can take the top in and out easily. I used a scrap 1/2" hard balsa plank and a 1" piece of triangle stock and a piece of .030" x 1/2" brass strip stock. I glued the triangle stock to the plank using CA and the brass strip using 5-minute epoxy.

The rosette is not an exact fit to the extension, so I put it into place and used masking tape to mark where I'm going to need to trim it.

Before gluing the top, I need to seal the wood to prevent the glue squeeze-out from staining the edges. Because I'm planning to use hide glue for the bridge and extension, so these areas need to remain bare wood.

First, use tape to mark the boundaries of these areas.

Fill the area inside with tape and remove the boundary areas.

Open up the bridge alignment pin holes.

 Put the bridge into place.

Carefully cut through the tape around the bridge making sure to not cut too deep..

Perfect bridge mask.

This next photo deserves a little explanation. I'm using dewaxed shellac to seal the wood because it provides a barrior between the wood and the glue and is an excellent base for subsequent finish coats. It also provides a nice color to enhance the grain of the wood.

I will be putting a lacquer finish onto the top. But, shortcomings of bare nitrocelluouse lacquer are well-documented. In short, it's delicate and requires careful handling.

In the aviation world, nitrocelluouse lacquer is known as nitrate dope. It is an excellent base coat because it sticks to most anything, including wood, fabric and metal. And, everything used as a finish coat will stick to it. While it makes an excellent primer, it's never used as a finish coat because of its lack of chemical resistence.

That's where butyrate dope comes in. It's extremely durable as a finish coat because it's resistent to most chemicals, including gasoline, oil, nitromentane, alcohols, etc. In fact, only extremely harsh chemicals like MEK, acetone, touluene, etc. will dissolve it. But, butyrate's shortcoming is that nothing else will stick to it, but more butyrate. So, it's a terrible primer, but a fantastic finish coat.

In addition nitrate and butyrate are available in two formulations: tautening and non-tautening. Tautening dope is used on natural fabrics like linen, muslim, etc. to shrink the fabric. Non-tautening dope has plasticizers added to it which weaken the shrinking. They will still shrink over time, just not as much as tautening. Non-tautening is used on synthetic fabrics like polyster, which are shrunk with heat.

So, I'll be usng the nitrate dope for the build layers. Then, once the top is smooth, I'll switch to butyrate for the finish layers. In the end, I'll have all the benefits of a lacquer finish and none of the shortcomings.

I would love to use hide glue to fix the top to the body, but the kerfing is plastic and hide glue doesn't stick to plastic. So, I'm pretty much stuck with using epoxy. I did a quick review of the different formulations of Hysol and decided to use 0151. It's optically clear, but more importantly it's temperature range is -35°F - +160°F and it has a 60-minute working time.

If ever the time comes where I need to remove the top, I just need to heat the glue to anything over 160°F and it'll soften enough to break the bond. Of course, this also means I'll need to take care not the leave the guitar in a hot car, but that's already a given with almost any guitar.

I painted the top with a coat of shellac to start the process. I let this layer dry overnight. I sanded it with 180-grit, then 320-grit and applied a second layer. I will leave this layer alone until the top is glued into place, then I'll sand it smooth and start adding the nitrate build layers. 

Thanks for the kind words, guys.

I've learned a lot about guitars while working on this project. My background in model aviation has definitely helped because a lot of the materials and tools are the same in both areas.

I'me really close to gluing the top into place. One of the small jobs that needed to be done is replace the missing binding from the end of the fretboard extension. I ordered some 'cream' colored binding from StewMac, but it was too dark. I found all kinds of ivoroid binding online, but I didn't want to use that because ivoroid has 'grain' molded in and it wouldn't match the binding already on the guitar.

I ordered some 'cream' colored binding from allparts.com and it's almost a perfect match. I molded it using the binding tool I made and my heat gun. I glued it on yesterday with 5-minute epoxy, then scraped it down.

It's not 100% perfect, but I'm very happy with the results.

Well, the top is on.

First order of business was to prepare the area where the fretboard extension gets glued to the top. I peeled off the tape and applied a coat of hide glue and let it dry. I also applied a coat of glue to the back of the fretboard extension.

After the epoxy holding the top dries, these will get a fresh coat of hot glue to reactivate the dried glue and clamped together.

I made the bridge clamping caul out of two pieces of scrap 1/4" birch ply and glued them together with CA. This will also act as a backstop for when I drill out the pickup wiring hole so it doesn't bust how huge chunks of the rosewood bridge plate.

I applied a bead of Hysol 0151 to the kerfing and at the very top underneath the fretboard extension.

This is the applicator gun. Anyone whose seen the part of the factory tour video where the worker is gluing the rosette into the groove of the Legend top should recognize this tool as it's the same as the one shown here. I'm not sure which Hysol epoxy they used, but it's probably the quick-drying variety. The 0151 definitely takes a full 24 hours to completely harden.

Dropped the top wood into place and wrap the rubber bands around the bowl. Each wrap is a single rubber band looped either two or three times, depending on the location. Lengthwise wraps got two loops and spanwise wraps got three.

I was going to use binding tape, but the top wood warped slightly after the braces were added and parts of the top didn't want to sit flush. The rubber bands applied pressure to these areas to hold the top flat and tightly against the kerfing all the way around the bowl. They also squeezed the bowl slightly against the top. There are a few gaps between the wood and the purfling here and there, but I'll fill these with epoxy so they're level with the surface.

The glue is dry and I removed the rubber bands. I reactivated the glue between the fretboard extension and the top, then clamped them together for about 30 minutes to allow the glue to set.

The rosette has been sanded to fit and it goes into place nicely. I also dropped the bridge into place so I check the neck angle (looks good!) and so I could ogle what the finished product would look like. (looks good!)

Now, it's onto the finishing process. First up will be to mask the entire guitar and start spraying the nitrate dope and leveling the surface.

Tap tests show the top is very resonant. I almost want to glue the bridge down and string it up to hear what it sounds like, but I will resist the temptation and finish it first so that once I finally get the bridge glued down I can just enjoy it from then on.

Fun, fun, fun!