Sen Guitars

2020-02-19

Making the sides

Making the sides

20191128
While waiting for some of the glues to dry, I began to thickness the sides.
At first I scraped one side smooth first.
This will be the outside sides with no knots visible
The other side with some some knots will be in the interior of the guitar.

Damn this wood is damn hard to plane, causing some tear out but luckily the stock is pretty thick so by the time I scrape them out the tear-out becomes level.
I switched to my high angle plane to prevent the tear-out and the HSS iron works wonder; remaining sharp after numerous planing.

Scraping the sides

Outer side of the sides scraped

Thicknessing the sides with HA plane

20200207
More thicknessing done on the 2 sides pieces.
Other than measuring the thickness by the thickness gauge, I also flex the piece.
When flexed the side piece has to be pretty flexible.

Both sides thicknessed

All the shavings...

20200219

Bending the Sides
After thicknessing, the next step will be to bend the sides.
Before bending I need to mark out roughly where the curvature points are.
i.e. which part is the waist which part is the upper bout etc...
Once marked I can start bending.

Recently I bought a properly bending iron.
The main difference is that it has a flatter curve portion on the iron as well as a tight curve portion.
This allows me to heat up more sides before attempting to bend.
This makes the bending job a lot easier and the bent sides are smoother in curvature.

Bending the sides

One side done

Both sides done

The bending set up - new side bending iron.

2020-01-16

Bracing the top

20191010
The required braces were prepared before hand by splitting and ripping from the stock and then planed to size.
Usually splitting produce more waste but it can ensure that there is no run out on the brace stock
If the supplies were obtained from a good supplier, you can afford to rip it instead of split it.
Of course that depends on your guitar building principles.

When the braces are prepared, I lay them out on the top.
Also I draw the bracing on the top and cut the braces to length.
For this build, I will also be using carbon fibre in addition, in order to reinforce the top more.
I had some wonderful experience in terms of using CF on wood and would like to try out on guitar.
The first step using CF is to glue the tow onto the top first using epoxy diluted with alcohol.
Then the brace will glue on top of the CF tow.
Finally the brace is capped with the CF
This will produce a very stiff braces in general.
However a good tuned top is neither overly stiff nor loose, so the balance must be there.
When optimally tuned, the final mass will be lesser than the normal braced top.

For this build I also modified my go-bar deck.
I make it stiffer and cleaner easier to use.

Laying out the bracing pattern. This is my bracing pattern

My modified go-bar deck

"Painting" the carbon fibre tow onto to the top.

Carbon fibre base all done.

Gluing the centre 3 braces

20191022
The bracing stage is always done in stages, as we need to carve the braces.
If not sometimes the other braces are in the way of the carving.
For my case, I carved the centre 3 braces and next will be gluing the Bouchet brace.
The Bouchet brace need to fit over the centre 3 braces.
But for the outer brace the outer fan brace will fit over the Bouchet brace instead as it decrease i
n height at the ends

Preparing the traverse brace aka Bouchet brace

Carving the centre 3 braces

Fitting the Bouchet brace over the fan brace

Gluing the outer brace.

Gluing the lower bout traverse brace after fitting the centre fan braces. This brace also commonly known as the Bouchet brace.

Shaping the traverse brace

20191031

Gluing the last 2 outer fan braces

Another view. Note that the fan brace is overlapping the Bouchet brace instead.

The braces carved.

A closer look at the outer braces

From the other side

Gluing of the treble bar.

20191107
The braces were carved to shape and tapping measurements were taken and compared to ensure of the optimal stiffness.

Bracings carved

another angle

20191113
Next the sound-hole reinforcement donut is glued.
There is some difficulty here as the bracing extends into the reinforcement.
Also there donut need to cater for the gluing of the tornavoz.

Gluing of the sound hole reinforcement donut.

20191128
Next the tornavoz is made and glued into a ring.
And some reinforcement veneer is glued to the top which also beautify the top.

Glued the veneer to the top

Glue the tornavoz into a ring.

Tornavoz done.

20191219
The 2 side braces are glued next.

Gluing of the side braces

20191224
Silent night! Next the 2 main traverse brace is made.
I use a lighter material to make the traverse and intend to wrap it with CF to increase the strength.

Making of the 2 main support traverse brace

20200103
Next the 2 traverse brace is wrapped in CF cloth.

Traverse brace being wrapped in CF cloth

The final part being glued

20200116
The traverse braces is glued to the top and the entire top weight is measured.

Top total weight is about 197g which is within the expected range.

The 2 braces are glued to the top.

2019-09-05

Thicknessing the top

20190905
I began to thickness the top as the tedious rosette process was done.
With my large kanna plane, I thicknessed the top and it leave a gleam on the top when seen under light.
As the top was being thicknessed, I also take note of the mass and the frequency response as well as the flex on the top.
When the readings reach my desired range, I stop the thicknessing and it was ready for the next stage.

Thicknessing the top with my kanna

Another view

Look at the shavings

Tapping the top

Analyse the frequency

Final mass of the top is 133g in line with my other tops of similar density

2019-08-30

Making the rosette

20190502
I started designing and making the rosette while I was doing the neck and other things.
I wasn't quite sure how the rosette would turned out so experimented quite a fair bit in making the tiles for the rosette.
The motif I had in mind was based on the Romanillos arches but I wanted to simplified it a little.
No much photo was taken during the making as I was concentrating on the making instead.
In the end it turned out pretty well, I'd say.

The hard part is to form the arches.
This was achieve by having 2 blank with a triangular cross-section profile.
One blank was planed with a convex based plane while the other having a concave plane.
The final part was sanded using the blank itself to ensure the fitting.
Finally to glue up, a black veneer was sandwiched between the 2 blanks.
After that the blank was cut into tiles.

Arches tile - 2 tile form a arch

Next was to form the pillars which support the arches.
For this I use several blanks which include the red coloured bloodwood.
This part was relatively easier.
As the arches were formed using white as background the pillar section was similarly using white as background too.

Gluing the blank to form the tile for the pillar

Gluing the blank to form the tile

Cross section of the pillar tile

20190516
After the tile is cut they are temporarily laid out to see the effect of the rosette.

Pillar tile cut

All the cut tiles

Trying out the tile layout to form the rosette

20190527
Subsequently more tile variation were added to the rosette motif.
It has evolved to become like a train bridge of some sorts.
I jointed a centre piece for the embedding of the rosette tiles instead of embedding into the main top directly.
This gives me the option of trying out various designs before inlay into the top.

Create a channel for inlaying the rosette tiles

Testing out the rosette tiles motif

The base layer inlayed

20190603
The inlay tiles were planed down to level and I proceed to cut the channels for the other pillar motif section.

Plane the tiles to level

Scribing the 2nd channel for the pillar motif tiles

Route the 2nd channel using router plane

Channel cut

Layout the pillar motif tiles

20190606
After the 2nd channel is cut, I began to inlay the 2nd set of tiles with a pillar motif.
In between the pillars, I create a tile that sort of look liked water body with that green blue lines.
So together it looked like a sort of train bridge.

Inlay the 2nd set of tiles

Main motif done

20190626
After that I level down the main motif channel mostly by sanding.
All the tiles were essentially end grain and it doesnt take planing too well even with a sharped low angle block plane.
After that I also cut the channel for the surrounding purfling theme.

Central rosette theme level down

Another angle. After sanding the colour also looked better

Channel for the outer purfling is cut

20190711
The outer purfling is inlayed

Inlaying purfling

20190726
After both purfling is inlayed the rosettte is cut to shape.

Inlaying both the purfling

Rosette cut out roughly

20190729
After that the rosette blank backing is thinned down almost to the rosette tiles itself.
This is to prepare for the inlay into the sound board.
Subsequently the channel is cut into the top and inlayed onto the top.

Thinning down the backing

Cut to rosette shape

Marking the rosettte location

Routing the channel

Inlay the rosette

20190806
Following that I added a tinge of red purfling to the rosette to make it more compatible with the back wood.
The final rosette looks good and it is the most complex rosette to date.