Post #18 - Kerfings installation for top.

Since clean up of back can be done through the soundhole, I'm installing the soundboard first.  This way so glue clean up of the top can be done before  the back is installed.  Below are pics of the top kerfings being installed using glue and clamps/clothespins. You'll note rubber bands for each clothespin to provide greater clamping pressure. 

Post #17 - Assembly prep - rims and back brace profiling

In preparation for the soundbox assembly, I had to set the rim height.  I followed the suggestions in the Cumpiano chapter on rim assembly for steel strings.  The tail block defines the height of the rims from the tail block to about 2" below the waist, called the "peak".  From there, the rims reduce in height generally linearly to the head block.  I scribed the line on the interior of the rims to help guide the process for plaining with the block planer.

Below is a picture of the rough shaped-rim.  I'll take some critical measurements and fine tune, and it will be ready for the kerfings.

In preparation for shaping the kerfings, I had to put together another jig - a radiusing sanding stick.  I generally followed the suggestions from this site for building one.  Below you can see the two sanding surface blocks glued to a 2' piece of stock.  I used shims to set sanding angles at approximately 1.5º and 5º.  

The last piece of preparation was setting the back bracing profiles.  Below you can see the braces before profiling.

Here are the braces after rough shaping with a chisel.

Here are the braces after clean up shaping with a block sander.

Here are the completed braces on the back. 

Post #16 Error correction - back bracing.

After clamping down the center two back braces, I inspected the upper bout back brace (B-1) and discovered it was not perfectly parallel with the other braces.  I ended up removing it with hot water, a hair dryer and a spatula knife.  Below you can see the brace removed and the back cleaned up for re-gluing.  It was back to the bench belt sander to clean brace B-1 before installing.

This time I tripled check the square. 

And then installed the rest of the clamps.  After some glue squeeze out clean up, it was time to wait for it to dry and set up.

Post #15 - Back bracing part 1

I caved in and used a moist towel to clean up the glue on the back.  Just to be safe, I clamped the back strip down again after the moist clean up and allowed it to dry before moving on. After the clean up it was time to mark the bracing locations. I used my template to mark the back brace locations.

Using a square, I scribe the saw lines.  Portions of the center strip are removed to accommodate the rear braces. The square is also used to guide the saw for cutting the center strip.  A little painters tape for protection.

Below you can see the portions of the center strip removed and cleaned with a chissel.  I finish the clean up with 120 paper.

Here are four back braces being dry fit.  I use shims on the side edges of the back to help maintain the radius when the braces are glued down.

Here are two braces being glued down.  Again the square was used to align the braces while clamping.  A bit of clean up for the glue squeeze out and then wait a bit for it to dry and switch to the other two braces.

Post #14 - Rear bracing progress

I set up a fence on the band saw and ran the spruce stock to rough cut the back brace pieces.  Each piece was then leveled on the drum sander.  I used a 25" fiberglass radius template to draw a scribe line on each piece.  It was then on to the belt sander to radius each piece to the scribe line. 

Here are all the pieces after the belt sander.  

The next step was to form the cross-sectional radius shape.  I started with a block planer to knock down most of the corners and form the general conical shape.  It was a nice day outside, so I set up the bench outside to avoid accumulating interior saw dust.

Here is a finished "wider" rear brace for the lower bout. 

Here is one of the upper bout "narrow" braces before radiusing.

Here is the same brace after initial radiusing with the block planer.

Here are the finished pieces.

I went ahead and installed the back center interior brace.  Need to wait overnight for the glue to dry. 

Post #13 - Soundboard complete.

The bridge plate has been installed as well as the finger tone bars.  Below you can see the finger bars before final shaping.

With a bit of chisel and sanding work, the finger bars are now in the final shape.  Here are the finger bars on the treble side.

I provided beefier fingers on the bass side.  I scalloped one of the fingers.  In the photos below you can see the rough shaping after the chisel work, and the final shape after sanding.

I spent a bit of time with the chisel and sandpaper to reduce glue squeeze out.  Some luthiers use water to clean up glue squeeze out, but I have a concern that the water may also weaken the glue joint between the braces and the top so I prefer a dry clean up.  It is a tough balance act between removing enough squeeze out without damage the top or adversely impacting the glue joint while having a clean enough top.  Luthiers are generally meticulous about a clean top so I may end up going over it one more time for final glue clean out inspection.  I also knocked down any sharp edges on the braces.   Here is a pic of the top after final clean up (I still have to glue in a cloth reinforcement at the x-brace intersection).  Now on to the back, but first I have to make the braces from spruce stock.

Post #12 - Clamping update

More top braces and head and tail blocks.

Post #11 - Minor update: gluing down the cross braces with clamps, again with liquid hide glue.  Clean up the glue squeeze out with moist rag to make glue clean up easier after drying.

Prior to gluing down the braces, I notched out one of the x-brace legs to receive the tone bars.

Post# 10 - Bracing set up

Now the that rosette and backstrip are done, I cut the top and back on the band saw to approximate shape in preparation for bracing set up. 

Since the previous post of the top didn't show a good pic of the rosette, I'm posting another shot.  As is customary, any imperfection toward the neck (e.g., using filing materials) will be covered by the fingerboard.

I drew up the bracing pattern for the top using a typical Martin style.   The cross brace is situated 1.25" from the soundhole; otherwise, I generally followed the bracing plan from the stew-mac Herringbone plan, with just a few modifications to conform to the Martin plan.

Post# 9 - Backstrip finish

I used painter's tape to protect the back. I'll be using a block planer to bring the back strip down to sanding level.  The back was clamped to the workbench with cauls and weights.

Here is a close up of the strips that are planed off.  Once I get it close to flush, I'll switch to sanding with a block sander and 120 grit paper.

And the finished backstrip.

Post #8 - Rosette and backstrip update.

Since it easiest to sand pearl to bring it level, I ran the soundboard through the drum sander for several passes until the rosette inlay strips were close to level.

When, it was close to flush, I mounted the soundboard back on the work bench, where I used a palm sander to sand down until almost flush.  Then, finally hand sanding with a block sander.  My outer ring cut was not very accurate, and so the gaps will need to be filled in with a mixture of sawdust and glue.

For the backstrip, I am using the "HD-style" zig zag backstrip.  I set up a straight edge fence using a level as shown below.  The router will glide along the fence to route the cavity for the backstrip.

Here's the stew-mac binding/router attachment mounted to the dremel.  I set the depth of the cut to be about half-way through the thickness of the back.  

To get a clean channel, I performed a pass on this side, and then flipped the back around, and made another pass on the other side.  After a few tiny adjustments of the fence and a few more passes, the channel width was  just right.

Here, I test dry fit the backstrip.

I'm trying the Titebond liquid hide glue for this build and used that for gluing the backstrip into the channel.  Below, I'm using a straight edge and a few weights to "clamp" down the backstrip.  After drying it will be time to level it, and move on to the bracing.