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2011-09-30

Carving the fan brace

Well this is consider the most enjoyable part of the guitar building other than stringing it up and play it.
I managed to carved the fan brace using little planes which I bought for violin making.
The planes are Ibex plane copy but made in China.

First I reduce the brace height to 3mm and then shape the cross-section profile to be rounded.
Finally I use chisel to smoothen the lengthwise profile to taper to 1mm at the ends.
The tapering starts just aftert the bridge and for the front part is just a short taper (maybe about 20 mm)

Here is the pics.
Removing the go-bars

Carving using the mini planes

Measuring the height of the braces

Removing bulk of the height using the bigger plane

All braces height done. Can see the doming quite clearly

Chiseling the sides of the brace to be rounded.
I just sharpen the chisel so it's very easy

Chiseling the end taper

Can see the lengthwise profile of the braces.

The mini planes close up

I taper the outer edges of the donut

The fan braces carved.

Next I cut the closing braces to size and glue them in.
Following that I glue the side braces but that's where I made a stupid blunder...
Originally I had the idea that I should use thin tall brace for the treble side and fat wide braces for the bass side.
But I mixed them up and the fat brace ended up at the treble side...
No choice but to go with this flow...

Gluing in the closing brace.

Gluing in the side braces
Can see the taper in the donut. Looks quite nice to me

Next I began to saw the apertures in the harmonic brace.
I decided to leave the harmonic brace at 23mm tall but with a larger opening instead.
Also the profile of the parts which will be glue onto the top will not the straight, this is to reduce the stress on the grain lines.
In the middle part which is glued next to the donut, I try to extend the curve of the donut into the harmonic brace.
After all is cut, I shape the brace into a smooth curves.

Drilling the hole in the lower harmonic brace or Lower Traverse Brace(LTB) and cut using a coping saw

The bottom profile of the LTB.

Checking out how the curves looked.

From the other side.

After the glued dried for I began to carved the closing brace and the side braces.
And after that worked on the UTB
The top weight is now 190g within my target
Well if possible I would like to down further maybe in the region of 175g
But so far the tap tone sound good.
A bassy ring with good sustain.

Ready to be carved

Down the height of the closing brace

Height done

3mm max for the closing brace.

The braces all carved! Looks nice to me.

Carving the UTB. Drill the holes first.

Use coping saw to saw the aperture

Chisel them straight followed by file

Done
Top weight is now 190g within my target :)

2011-09-28

Gluing the fan struts

After preparing for so long, I finally glued on the fan struts and the soundhole reinforcement donut.
I heat up the HHG and on the dehumidifier and prepare to glue.
Before gluing I had a final check on the struts length and trim accordingly with a chisel.

Once ready I position the top and hold it down with 2 go-bar one at the waist and the other at the bridge region.
I apply the glue to the donut and glue on the top.
First I use 4 go-bar to glue the donut; this so that I can see the alignment of the donut.
If I use the wood straight away I can't see if it's aligned properly or not.
After it stablised, I switch to using the center screw and a wood to screw it down.
But after gluing the outer most fan brace, the block of wood was blocking it so I switch to a smaller piece of wood from my previous solera.

To glue on the fan struts, I first clamp in place a steel rule to guide fan strut to prevent it from skidding around.
I started with the center struts and work outwards. 1 2L 2R 3L 4L 3R 4R
Actually using go-bar isn't as easy as I thought it would be.
The go-bar has to slide from the same plane as the fan strut direction so prevent the strut from skidding around.

Here are the pics:
Final check of the struts length.

Securing the top in place

Applying HHG to the donut

Gluing on the donut.

Securing the steel rule

Gluing the center strut

2nd strut

The wood blocking the 4th strut outermost fan strut

Change to a smaller wood strip to secure the donut

All done

Side view

Close up view can see the doming quite clearly.

Zoom in the donut region

Can see my HHG by the side :)

Next to come carving of the struts...

2011-09-27

Making the go-bar deck

In order to glue the struts, I need to make the go-bar deck.
I was thinking to attach the top deck to the solera, which I will be making using 2 pieces of 1cm thick plywood.
This probably won't be strong enough and so I added a cross-bracing to the top.
I started making the notches in the bracing and it's a good way to improved my chiseling skill.
Now I am pretty confident of making a normal dado or mortise-tenon by chisel.
Not perfect fit but acceptable.
I realised the crucial part is that the chisel must be real sharp.
The rest is just getting them to fit.

Gluing 2 pieces of plywood together

Sawing the edges straight. After that I followed up by chiseling and planing to make the 2 pieces flushed.

Chiseling the notch

Cleaning the notch to make them fit.

Notch done

Gluing the x-brace down.
The middle part I use another scrap to press down.
I don't have any clamp that is that long reach.

X-brace done. The X-brace will help to keep the plywood flat too.

After that I drilled the holes for the top and bottom board.
I've decided not to attached the top board to the solera.
This makes it easier for me to use the deck for back struts too.
Due to the position of the X-brace I could not drill exactly at the corners but I have to drilled to fit the 2 boards.

I assembled the board with 3 legs, for the last leg the hole had some chipped pieces
I glued them back.
With just 3 legs, the assembly is kind of wobbly...
I wonder would it be able to withstand the pressure of the go-bars?
The last time I use the Aluminium go-bars on the table the entire table rose up...
I had put books and other heavy weight to weigh it down.
Well if the threaded rod doesn't work then I have to build using wood legs.

Drilling the hole 10mm to allow the threaded rods to go thru'

Assembly.

The parts

Go-bar deck assembled

Another view

Another view

Testing the deck. Test run of the gluing process and adjusting the height of the deck to exert enough pressure and the go-bars are not too curved.

Close up of the doming of the struts

I have made some more go-bars for the gluing.
4 for each struts 7x4 = 28 and 2 extra.
That should be enough to start the gluing process.