Sen's Guitar Making Blog: Making the Heel Block

While I was bending the sides halfway, I suddenly realised I have not done up the heel block yet.
Well why I say the heel block, similar to the concept of the steel string world, I intend to make the heel block first.
However this will be a still a traditional Spanish foot.
It's just that I will only glue the neck to the heel block after the binding and purfling are done.
One problem with my last build is the binding and purfling.
The presence of the elevated neck makes the installation of purfling and binding a big problem.
Now I will align the heel block and neck together first and then proceed to assemble the guitar; glue the sides to heel block and end block and top.
After closing the back, I do up the purfling / binding and finally glue the neck to the body.
As I have inserted guiding holes, the alignment of the neck to heel block / top should not wonder off.
Another advantage of this way of build is that I can choose to install the fretboard / frets on the neck separately before gluing to the main body.
This is killing 2 birds with 1 stone.

Now more to making the heel block.
First I saw the excess part from the neck to form the elevated neck angle.
I had previously marked out the angle.
After sawing I began to plane the neck to the line marking.
After checking for squareness, similar to planing a scarf joint, I began to work on the heel block.
I use the top to measure the number of pieces needed for the heel block.
The 1st piece I intend to cover the main bulk of the top up to the UTB.
This is said to give more body to the treble; strictly speaking an elevated fingerboard design already caters for this part, but I wanted to strengthen this area to prevent the neck from lifting from the body.
A strong C-block will enhance the structure integrity of this part.
Also with a elevated neck (above top) heel block (below the top) sandwich assembly, it will prevent top split at this area.
This type of split which is adjacent to the fingerboard is one of most common split of the guitar top.

Neck I plane all the heel block piece to get a smooth surface for gluing.
I need about 85mm thick (to be adjusted later) for the heel block, so I plane one of the pieces to thinner thickness.
Also I plane an angle to the 1st piece that is glued to the top, this angle will correct the top sloping angle back to perpendicular for the rest of 3 blocks.
After that I mark out the heel curve and 12 fret side joint mark on the heel block.
The pieces are ready for gluing.
After going thru' the pieces with the wooden plane the surface is shiny.

Saw the slope from the neck.

A step at the neck, the rest of the waste will be planed away.

Planing the waste to the line.

Smoothen with the wooden plane

Checking for straightness

Side squareness

Gleaming surface after planing with the wooden plane

Measure the 1st piece of the heel block. It covers all the way to the UTB.

All pieces sawn

Saw the angle for the 1st piece

Plane it smooth

Thickness one of the pieces

All pieces ready to be glued

The entire neck.

Another view

I saw 2 strip from last piece of the heel block where the foot is.
These 2 strips will be used for the wedge to lock the sides into the slot.
Also a wide foot will look not so nice as a narrower foot.

Saw the strip out for the wedge

After planing the sides the foot is ready for gluing.

I glued up 3 stack of heel block leaving the last piece unglued; the one that is gluing to the top.
I will explain that later why.
When I check the 12th fret line, I notice the heel block 1st piece (nearest the top) is slightly longer than the space available on the top (from 12th fret to UTB).
So I had to cut a groove in the 1st piece stack.
This will serve to support the UTB too, which I think is a good idea.
I use my mini douzuki saw and my favourite rebate plane to to the job.
The curve is done using the file.

Sawing filing planing the groove for the UTB. This will support the UTB more.

Check fitting. It's not perfect fit but it's ok more will be done later.

Now is to drill the guide holes for the final assembly when the neck is glued onto the top and heel block.
Yes for this build the neck wont be glued to the heel block during assembly.
It will only be glued after the entire body's binding and purfling is done.
With the neck out of the way, the purfling can be done easily.
Normally for elevated neck design, most maker will make a mortise tenon neck but I prefer the Spanish slotted foot design neck so I chose to do it this way.
After drilling the holes; 1 on the heel portion the other 2 on the top to heel block portion.

The next portion is to plane a groove to the heel block so that the top is flushed with the front port of the heel.
This is like the normal neck where the top is flushed with the neck.
Now that our neck is on top of the top, the top will flush with the heel portion.
So I use a douzuki saw to cut a slot roughly the depth of the top's UB thickness.
Then I set the router plane to the top's thickness (2.14mm) and started to remove the wood.
The router plane can be used to remove to the exact depth in between the 2 ends.
I must say the LN router plane is very useful, never regret buying it.
The end section is removed by plane.

Drilling the guide holes

Guide holes drilled

Top thickness at upper bout is 2.14mm

Sawing the slot at 12th fret region

Setting the router plane depth

Removing the wood after the slot. The 2 ends of the router plane is supported.

The 1st portion removed

All done fitting nicely.

Roughly how the neck assembly looks

From the front part

Time to glue up the heel block since all the preparation (guide holes drilled) are done.
No special tricks here, just heat up the surface, apply the hide glue and align and then clamp.

All items prepared.

After surface is heat up hide glue is applied to both surface

Aligned and clamped

After the entire block is glued, it's time to cut the slots.
Again this time round I will be doing the wedge method.
But instead of using that neck jig which doesn't really work due to the inaccuracy in making the jig, I just use a guide block (with the correct angle) to start the saw cut and continue using the douzuki saw.
The block is about 95 degrees.
After drawing all the lines I clamp the guide block and started the sawing.
I use the mini douzuki for better control and continue with the normal size douzki once the slot is deep enough.
I also marked the portion in the heel block (the surface that is to be glued to the top) till where I should stop sawing, that's about 20mm from the center line.
This gives about 40mm wide to 80mm high (triangular) of wood to hold the heel to the heel block.
This should be pretty sufficient for strength.
After the saw cut I saw the rear line at a slight angle to form the wedge.
I just simply estimate, basing on the wedge blank which I cut out from the foot block earlier.
Finally I chisel out the slots and shape the rear heel block abit.

Plane the side flat for reference

Guide block clamped.

Start the cut with the mini douzuki for more control and precision

Continue with the douzuki saw (more depth)

Both slots cut

Chisel the slot

Both slots done.

Saw away the rear part of the heel block to form a triangular profile

Done

Next I began to shape the heel.
At first I began sawing away the 2 sides for the triangle heel shape (looking from front) but I realised it's easier to saw / chisel / drill the heel (looking from the side) C-shape first.
So I use a Forstner drill bit and remove some of the material first and chisel / plane / file away the rest.
Sapele is damn hard to shape! This probably will be the last time I am going to use a sapele for the neck.

Use forstner bit to remove the waste.

Most of it removed

Saw away the waste

Saw away the side shape of the heel

Use rasp to shape the heel.

Not quite done, checking the shaping with the neck in place

Did a few things more for the heel block; sand the curve smooth with my roller sander drill attachment.
Next I also adjusted the heel's side profile making it more slim.
I have not chisel the slight curve into the front profile, I'd probably do that after I assemble the whole guitar.
This is because the neck will be install at the last part.
I did up the wedges and check the alignment for the sides.
It fit the heel nicely w/o gaps.