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2008-07-03

Binding and Purfling (Cutting)

Binding cutter tool selection
Till now I am always considering what tool to cut the binding rebate.
1) Make a purfling cutter (like gramil) and chisel the rebate.
2) Dremel based cutter
3) My new Maktec Laminate Trimmer cutter

For 1, I will need to make the cutter, which would take some time.
Also I had problem of finding the correct material for the cutter.
I have already got myself a set of good chisel, so it will put the chisel to good use.

For 2, I need to make the router attachment.
Also, if I need to have a fine adjustment ability, I need some thumb screw with a catch.
Finding the correct screws are quite difficult.

For 3, the existing base and attachment are already suited for the job.
However I still need some practise in routing as I have never done any routing before.

Using the trimmer
After some experimentation and trying to do the router attachment for option 2, I gave up making the attachment.
So I chose option 3 and practise the rebate cutting.
The routing experience was pretty fun; but not the cleaning up experience.
The trimmer basically spurt all the wood dust across the room.
I never realised that a trimmer can spurt out so much dust...

Regarding the loose bit, I emailed the Makita company, they responded pretty fast.
They said I need to get the 6mm collet cone instead which cost about 2 to 3 dollars.
Anyway, I bypass the problem; I got 1/4" bit instead.

Anyway, while I collected the trimming bit at Kelantan lane / Jalan Besar area, I got some more 1/4" router bit instead.
I also got some hardware to make the 2nd option easier.
I will need the option 2 if I were to do some inlay and bridge drilling / routing.

Cutting the binding rebate
After some practise, I cut the rebate.
To minimise tear out, I cut in the direction from the widest bout (upper and lower) to the waist and butt aread.

Routing direction to minimise tearout


Routing the rebate.


Dry fitting of the binding.


Another view


Close up view of the rebate at the waist area. As you can see I did not cut the rebate very deep, so the rose wood side is still visible.
If I decide to add in a purfling, then I will need to increase the rebate thickness.


After routing the room was filled with rosewood dust.



Purfling scheme consideration

I have not decided to add in a purfling or not.
The back strip was without any purfling lines, so in order to have some consistency I think will not add any purfling to the back binding.
As the binding and the purfling are of different colours:
Binding: white (maple)
Back: Rosewood (brown),
if I wants to add a purfling it has to be even number and of alternate colours i.e. BW purfling or BWBW purfling.

For the front the top is white (spruce) and the binding is also white (maple), so I need an odd number of purfling: B or BWB.
I have purchased a herringbone purfling, which might just be suitable.
If I decide to use this herringbone purfling, I can also ornate the bridge's tieblock and the headplate with the same herringbone purfling.

Here is a picture of the herringbone purfling.
to be added.

Cutting the butt insert rebate
Initially, I wanted to make a jig/guitar holder for holding the guitar while I work on the but region.
However after much consideration, I decide to just use the F-clamp and some spare wood.

Here is the clamping assembly.
First, I clamp some spare MDF to the table using the smaller F-clamps.
Then using the big F-clamp, I clamp the guitar to the spare wood.
The corksheet was used to prevent scratches to the guitar top.


Then using the Japanese Luthier Saw (douzuki saw) I started to saw the but insert rebate.
After a few rounds of sawing, the douzuki saw was too flexible.
I switch to use the Gent's saw instead.
The douzuki saw was good for other purposes and with little wastage.
Each's saw has it's purpose and suitable application.
The Gent's saw was having thicker blade and thus able to keep the line straight.
Douzuki saw was good if the cutting was done at a slight angle.
However for sawing the line, its almost held parallel to the surface, so it's hard to keep the sawing going in a straight line.
The metal rod was used as guide in the initial stage of sawing.


The sawing is done.
Now to chisel away the wood in between the saw lines.


At first I use the Marples chisel but later switch to the broader Diefenbacher chisel.
Coincidentally, the width of the butt insert was the width of the chisel.
During the chiselling, I managed to find a use for the 2 Cherries bent chisel :)
The front part of the insert was block by some wood and I was clearing the middle part of the insert.
The bent chisel will avoid the front part of the wood waste and work directly on the
inner portion.


The channel almost cleared.


Unfortunately I slipped and chiselled away some of the wanted portions...
Here is a view of my mistake.
Still pondering how to salvage the situation.
The easiest way is to widen the channel, but I am afraid that will weaken the end block joint as the side to the endblock glueing surface is reduced.
Alternatively, I can cut a curve portion at the mistake part making some sort of design.


A close up view of the blunder...


The end channel.



Binding rebate
I decide to include the BW purfling for the back and thus widen the binding rebate.
Now the kerfed lining blocks can be seen.
However I have cut the rebate too deep and the binding's height is now below the back.
2 mistakes in a one day.
One way of remeding is to add a side purfling to increase the height.


Another view.


Foot region.
The channel was first sawn and then cut using 5mm chisel, it is still to wide for chiselling.
I might need to get the 2mm chisel from LMI next time.






Side Track: My Gutmeier Guitar
This section is not part of my guitar building but rather pictures from my existing guitar.
I have a '98 Western Red Cedar Top/Indian Rosewood guitar made by the Baltimore luthier Ross Gutmeier.
It has an incredible sound clear singing trebles, deep bass and great projection.
I happened to change strings and took the pictures of the internals of the guitar.

The guitar's bracing patterns was based on the famous luthier Ignacio Fleta (Barcelonia).
It had 9 fan struts with a full slanting treble harmonic bar.
The top bout was padded reinforcement pad; the guitar was very heavily built.
The body and neck was built separately and joined using the dovetail method.
Ignacio Fleta was a making violin family instruments before building guitar which explains why he had chosen to go for this type of neck/body joint instead of the traditional one piece Spanish foot joint.

Here are the photos:

Th 9 fan struts with enclosing struts at the tail end.
In addition there is a slanting treble harmonic bar at the sound hole region.
The guitar is certainly built heavily.


The bulky neck block for the dovetail joint.
According to some OLFers Gutmeier is known to epoxied the neck to the body using plain butt joint instead of dovetail.


At one side of the slanted treble harmonic bar.
You can see the tiny brace pockey simiar to what I did with my braces.


The other side of the treble bar.
You can see the bridge pad almost span across the entire top region.


Here u see the back struts.
Fleta had 4 back strut but there are only 3 on my gutmeier