Preparing the Back for attachment

Sanding the rim
First of all, I taped the sand paper to the board and began sanding the side rims.
I read this method from the Cumpiano book.
When I worked on the upper bout, I realised that the Spanish foot section will disrupt sanding as the foot area is taller than the surrounding side rim.

At first, I wanted to make a radius bar, in order to sand the upper bout, but decided against doing it because it was too much work and the benefits wasn't alot.
In the end, I found a simpler way: attached 2 board on each side of the foot and paste the sand paper on the raised board.
The raised board is clamped to the main board using C-clamp.

Sanding the rim. One end is for upper bout with a raised side, the other end is for lower bout.


The raised side are held by a C-clamp.


Sand till no gaps in between.



Back struts
After finished sanding the rim, I proceed to work on the back struts.
Nothing special except for marking the position of the back struts to the rims.
The rest is just standard trimming and cutting process.

Back struts cut.


Taping the struts to the back.


Fitting to the rim


Sides marked (tape) and struts trimmed to fit the side rim.


Back fitted.


Shaping the struts
For shaping the struts, I did not use any predefined radius, but rather draw a free curve joined using french curves ruler on a vanguard sheet.
Then I cut out the curved sheet and draw a center line on the struts for transfering the curve to the struts, aligned on the center line.
To keep the gluing edge square and flat, I use a shooting board method.
I learn this method from a Erik Schmidt who was also a first time builder but with great organisation and great woodworking skill.
You can read the forum thread of his build here

I did not make a shooting board but simply raised the struts height using a cut out MDF and plane the curve accordingly.
(It was the same MDF which I had intended to make for the radius bar :) )
It was a simple and effective way compare to free hand method which I used the last time I did the back struts.
Keeping the gluing surface square is important for optimum gluing strength.

Shaping the struts using a shooter board method.


Another view


Yet another view


After the curve is done, I proceed to scallaping the struts to reduce the weight of the struts while keeping the strength (height constant).
My idea is to keep the end square and anything in between to have a curve cross-section.
I intend to keep the struts at full height and no tapering at the ends.
That is the main reason why I keep a curve cross-section in the middle and square at the ends.

Here is how it looks in final state. I think the curve can still be improved on.


View from the end.


All three struts done. The lower bout strut is thicker as it is the longest.


Another view.


I did some further work on the back struts.
I re-read the Rommanillos book on Torres and the back struts height was about 17mm.
Mine was over 20mm.
So I decided to reduce the height of the back structs.
Again the shoot board method was used but this time round I make the curvature less sharp more round instead.

Middle strut profile


Side view of 3 struts


Oblique view


Gluing the back lining
Finally the last task of the day is to glue the back lining.
I did consider to use laminated solid linings as I had 2 pieces of basswood about 90cm long.
But in the end I decided to just use the lining which I bought from lmii to save time.
I was lucky that I have bought clips previously from Daiso.
Surprisingly the quantity of the clips was perfect: 4 boxes of 8 clips each: just nice for the entire back lining.
The process was similar to the front lining except that now the back struts were there when I glue.
I had to position and match the lining according to the marking on the tape which I had done earlier.
All in all, it was a familiar process.











The lining glued.


I also glued the lining under the brace.
By accident I discover the height of the brace is about the same as the height of the lining.
So it kind of make it neat and tidy.
Maybe next time I will make a brace pocket holder for the line at this part.

Gluing the lining under the brace


Gluing done


Brace fits just nice




Glue the back crack

I finally thought of a way to glue the crack at the back: Clamp 2 pieces of wood sandwiching the back on each side of the crack and use 2 F-clamp to draw the 2 pieces of back towards each other.
Look at the pic for a better explanation.



The gap looks closed and hopefully the CA glue will do the job.
However, I was worried about the CA coloring the Maple back insert between the 2 back pieces.
Well just have to wait and see.

Here is the back after the gluing. The darkened part hopefully can be sand away.


Reinforcement for sound port
I also bend some basswood for a sound port reinforcement.
First I thickness it using my Stanley #4 (it's been a long time since I used it as I use block plane more)
The result wasn't too good but can be smoothen using a file.
Nonetheless I proceed to use a heat pipe to bend the piece and periodically checking the curvature with the guitar.
It was quite easy to bend especially with the water.
This is the first time I bend a straight piece from scratch the experience was very satifying.
The result was quite good.

The bent piece.


Cut and plane to side. However the back still needs to be smoothen.


I had glued the reinforcement piece to the back of the sides inside the body.
It will be ready for cutting of the sound port in the next session.
However, I still have yet to finalize the sound port design...

Clamping the reinforcement


Inside view



Consideration for gluing the back on
I had 2 options:
1) Glue the struts to the back and the back to the body
2) Glue the struts to the rims, and the back to the body.

Both of the way required different sets of tools.
1) I had to make some cam clamp or have clamps with enough throat length to reach the center of the struts.
2) I need to build some supports underneath the brace. This method is from Romanillos way of gluing the back.

You can read the Romanillos method of build from another great first time builder
Waddy, who is also another fellow OLFer.
Or his Photobucket Album

After some serious decision I decide to adopt the 1st method.
I got hold of some more new F-clamp with a longer throat.
The clamping was a familiar procedure.

Clamping middle and lower bout brace


Clamping the upper bout brace


After gluing the brace, I began to fit the back but it just wouldn't fit into the slots.
I had to adjust the lining (chisel away and glue new ones) in order to fit the back.

Back enclosed (not yet glued)


Fitted back inside view


I had also started making the caul.
Trying to get it fit the brace and curvature of the doming.

Caul


Binding attachment for the B&D RTX
To cut the binding, I needed 2 more tool: one is a attachment holder for the B&D RTX and the other is a gramil scriber.
I have began building the attachment out of MDF, basing the design on the Stewmac version of the dremel attachment.
There is a second part of the attachment which will allow the adjustment of height.
I intend to use spring and adjustment control using screws.
Again the base will be made of MDF.
There will be an edge guide to cater for binding purposes with screw adjustment: something similar to the Stewmac version which is a very refined made tool (but expensive)
The main holder for RTX body is not fixed, to allow for adjustment for tool squareness to the front panel.
However, I think the front part is abit too bulky and may reduce the footprint of the frontal portion.
This attachment can also be attached to my drill stand for using it as a bridge hole mini drill press.
Hopefully I am able to complete the whole attachment by the next session.

The B&D RTX Attachment holder 1/2 done: top view


Back oblique view


Front oblique view

Attaching the side to the top

Well first of all, I lost all my pictures for this session.
I took quite alot of pictures for this session and the SD card was unable to be read when I reach home...
Now all I can show is the end results of this session, which I took on another day.

In order to fit the MDF dome to the wood solera, I had to raise the height of the side supports.
I drilled the holes and cut the MDF into a small rectangular pieces.
The MDF piece will be inserted in between the side support and the pine solera base.
I grew to love the coping saw and the tenon saw: they are really a helper.
With proper technique, they can saw any wood as efficient as a Jig Saw and at a low noise operation.
Also, the manual sawing gives more control.

The assembled sides in a solera you can see the raised support.


Then in order to fit the sides, I had to bend the sides a bit more.
The process was rather quick as I had adjusted the side curvatures on a number of previous occasions.
With the solera (which I grew to appreciate), the main spring back (length-wise) can be contained with the side supports.
I simply tightened the screws abit and use the mallet to knock the sides into shape fitting the curve pencil mark drawn on the top from the template.
The fitting procedure was a breeze.

I chisel the heel area to fit the thickness of the top board so that the topboard would flush with the neck.
Then I use file to file it flat (causing my hands to blistered).
(Seriously I forgot totally about using the plane and scraper instead...)

I trim the sides at the center line first using a tenon saw.
Then I use Stanley T-bevel blade to mark out the angle of the Spanish foot slot and the sides.
Finally I saw the sides according to the marking and file the jagged edges.
The fiting was perfect (to my surprise actually).
I must give credit to LMII for provided such well-made necks.
The slot fitting was perfect with no gaps.

The heel. Noticed there is no gap between the sides and the heel. Kudos to LMII's pre-made necks.


After the fitting session, it was finally time to start the gluing process.
First of all, I glued the topboard to the neck making sure that the center line of both neck and topboard lines exactly.
I use mere naked eye looking down the line to ensure that both centre line are in line.
After apply the glue I use hand to hold them together for about 15 minutes or so before I apply the F-clamp to clamp them further.

After about another 15 minutes or so, I transfer the attached top to the solera and clamp it down there.
I fitted the sides to the heel slots and started the mallet knocking session.
The spring back is mainly lengthwise now.
So I adjusted the curves and determine the final location of the end block.

After being satisfied at the curves, I proceed to glue the end block.
I use the 2 F-clamps to clamp and a wooden plank down the sides to the top.
Finally, I glued the end block to the sides and down unto the top.

The end block.


After gluing the end block, the next step would be gluing the lining.
The lining which I used is a normal spruce kerfed lining.
The gluing is done in sections as divided by the end block, heel, and the traverse bar.
At first I used solely hand to hold the lining, but found a better way in the end.
I use a wooden block and clamp the block to the sides, pressing down on the kerfed lining.
As the kerfed lining surface is angled, and the wooden block is pressing on the angled surface, the force vector components will be applying to both the sides (horizontal) and the top (vertical).
After 15 minutes or so, the kerfed lining will be held in place and the clamp can be removed.

There are some sections which the struts extend into the lining gluing area.
I had to use chisel to remove part of the lining in order to fit nicely.
Overall, I like the smooth appearance of the lining.

Kerfed lining.






Detailed view of the open harmonic bar area


Top view


End view


Oblique view


Looking at the end.


View after removing from the solera a few days later.


Trimming the side
I started to trim the side rims's height using a block plane.
I slipped a few times and get a few bloody dings in my fingers.
Luckily the blood did not stain the top
Everytime after each making session I would be unable to carry out my routine guitar practice, due to finger ache or injury or blister.
Well seems like there will be no playing for the next few days.

Using a plane to trim the sides.


Now the main problem which I faced, not having a radius dish.
So, I can't really get a perfect curvature for the back.
However, I got some pretty good advice from a fellow OLFer, AlexM, on how to do it without a radius dish.
He did several guitars and the latest one sounded marvellous.
The lovely harmonics left a deep impression on me until that it sound he had added reverb to the recording...
Hopefully my guitar would turn out that good.

The curvature would be shaped by the back struts, with the center struts having slightly more curvature.
Then, using the back and do a dry fitting.
Use the file to adjust the sides to fit.
So long as the back is curved, it really doesn't matter if the curvature is not a spherical curvature (as in done in a radius dish).

The rims half done done.
You can see the uneven curvature.


Removing the back brace
Previously, I mentioned that the back has a crack.
Now I have decided to remove the current brace and use CA glue (super glue) to mend the crack.
Upon careful inspection, the crack might not be due to humidity swing problem but rather weakness inherent in the EIR wood itself.

Well first to remove the back brace.
I use my Japanese bevel-edge chisel to do the job.
It is a cheap and good tool for only just SGD2.
After chiselling away the brace, I then chisel the remaining spruce on the back
and use a scraper (paint scraper) to finish the job.

Chiselled middle brace.


Another view.


Close-up view. The glueing was surprisingly done quite well for the middle brace
The brace adhered full to the back.


Chisel away the remaining brace.


Chisel the lower back brace.
This brace wasn't well done.
The left side did not glue properly to the back.
I'm glad I decide to redo the back brace


Chiselling away the lower back brace


Using scraper to scrape away the remnants of the brace.


Another view


New back struts.
I made the lower back structs thicker because its a longer struct than the rest.




New tuner machine
I acquired Rubner tuner for AUD 66 from the Australian Luthier Supplies
They are a beauty with shiny brass back plate with simple elegant decorative border.
Together with a ebony button and black roller, and priced at AUD66,
the tuner is a good bargain.
According to a fellow OLFer, WaddyT, if we get in bulk from Rubner factory itself, we can get it for 20% cheaper.
If I go into making 10 more guitar, that's really a good option to think about.

New Rubner tuner with ebony button and black roller.


The Rubner tuner on the head


Look with back on


Close up at the crack

The Traverse Bar

It was a fruitful day.
I managed to completed gluing all the top's struts including the harmonic bars.

Carving the enclosing struts
First of all I carved the enclosing struts to shape.
I think my chisel skill is getting better and better.
I noticed the chisel getting a bit blunt from all the carving.
I'd better be starting to look for a honing guide soon.

Carving the enclosing struts.


Completed carving


Top down view


The lower traverse bar
For the traverse bars or harmonic bars, I start to mark out the windows that I am supposed to cut.
For a moment I was think whether to do it like Torres which was basically an arched window or some other open brace design.
In the end I opt for a simple rounded corner rectangle.
It was pretty easy process to carve out the window.
Next I used file to smooth the jagged edges.

Marking out the window


Drilling the hole


Sawing the window


Both window sawn


Test fitting the lower traverse bar



The upper traverse bar
For the upper traverse bar, I was think whether to make it a open or close.
Torres' upper traverse bar was close and thus his upper struts could made an angle with the outer fan struts.
In the end I decided to make the upper traverse bar open.
In order to support the upper bout, the upper struts was made straight instead of an angle.
For the making of the upper struts (no pictures), I plane it to shape for the cross-section and taper the ends before gluing the struts.
It's definitely much easier to do it with plane then chisel.

Both upper and lower traverse bar sawn


Close up view. (Noticed the straight upper struts)


Oblique view


From the other side. The upper window has been smoothened.


Side view


Yet another view


Test fitting with the sides. The traverse bar has been trim at the ends


The gluing process
It's time to glue the struts.
The upper struts are glued using all the F-clamps.
The traverse bars are clamp using the F-clamps at the ends and in the center is the good old center screw.
The screw was abit short and I had to cut 2 notch in the center MDF strip to lower down the thickness.
The notch served to stablise the traverse bar too.

Gluing the upper struts


Gluing assembly


Low angle view


High angle view


I thought I would post some more photos of the completed braced top.

I try to fit the side to the top, but discover have to trim the harmonic braces more in order to accomodate the sides.
Using a mini hacksaw and then chisel I manage to trim the braces.
Now the side fit in the top better, though the upper bout curve still need a bit of adjustment by heat pipe.


Here's another view


A closer view of the braced top