Custom Search

2011-12-28

Fingerboard

Well I am supposed to close the box but it was raining very heavily these few days.
The RH shot up to 80%+
This made it very unsuitable for closing.
So what I did was to start on the fingerboard.
I just scrape the surface smooth; the fingerboard that comes from LMI was pretty well surfaced.
I just need to shoot to square the reference side.
I had some someother ebony that definitely need more work to get it smooth.
Anyway the maximum thickness of the fingerboards are about 8mm only
I remembered wrongly and thought they were at least 10 mm thick.
This threw my calculation off for the neck geometry
I had to rework the geometry readings to get the correct action at 12th fret

Shoot and straighten a reference edge.
The slots will be saw square to this edge.

I made a mistake during the sawing of the fret slots.
I used the LMI 650mm scale length template and saw using the LMI jig.
By right it's dummy proof but well I managed to goof it up...

I saw according to instructions:
Using the 650mm side of the template slots, I double tape the fret board to the template.
Then I adjust the depth of the cut using the nut slot as a reference check.
After making sure everything is OK I started sawing.

For the 1st 2 slots I can see the slot marking on the template, but after that it's all covered by the fingerboard.
I had to slide the template and feel the pin slide into the slot.
That's why I made the goof up.
During the 11th fret slot sawing, I mistakely thought the pin was inserted into the slot.
(How could I have missed that!!!)
And what's worse I made the mistake twice.
As a result I cut 2 fret slot one before one after 11th fret.
And I didn't saw the 11th fret..

I didn't realise that initially.
When I took out to check how many slot I have done, I thought the slots looked very funny.
After inserting back into the jig then I realised I missed the 11th slot and cut one before and one after...
Anyway I continue the rest of the sawing and use PVA mixed with ebony dust to fill the slot.
But I think it will still be very visible.
I have to wait till it dries and sand it smooth to find out.

Preparing to saw the slot

Sawing the slot

The goof-up... patched with white PVA mixed with ebony dust. Some update after I sanded down the excess the fill up looks quite good. Certainly not invisible but quite ok. With a black fingerboard dye I guess it would look ok afterall. Thank goodness.
The patch after some sanding.
View from far cant really tell the patch mark.
Closeup shot can see rather clearly. The center still some more filling
The treble side.
After 2nd filling looks good as new. After the patch filling, I began to cut to shape the fingerboard. I roughly draw the center line and measure 26 from the center line for the but region (52 mm for the nut width) And at the 12th fret region I measure 31mm each side (62mm at 12th fret). After marking out I saw away some of the excess and remove the rest using a shooting board and plane. Ebony is really pain to plane...
At the nut, 52 mm
At 12th fret 62 mm.
Saw away some excess
Shoot the rest to the line
Fingerboard done
The amount of waste generated
How the fingerboard look on the neck
Close up view to align the center line.
So far so good.
Then I turn over and plane the back of the fingerboard.
The bass side should be about 1mm lower than the treble side.
This is because bass string tend to vibrate more than the treble string.
Alternative I can plane the top of the fingerboard but as Ebony is prone to tear-out, there might be blemishes...
So it's better to plane the under side so that even with some blemishes it's not visible.
I smoothen it with scraper and scraper works really well with ebony but the heat build up on the scraper is really hot to the touch almost like frying pan.
Think it might be good to make a scraper holder like the LV version.

Planing the underside of the ebony fingerboard

Before I close the box, I need to cut the fingerboard and the elevated part of the neck to shape.
As the sides are attached, there is no way a coping saw can be inserted.
So I just use a junior hacksaw to saw straight lines and chisel away the excess.
I had a small chip on the front face of the neck but luckily not too deep.
After that I use my chisel and file to shape.

Saw straight cuts on the excess part

Chisel away the waste parts

Chisel to match the sound hole

File to shape

Saw the corresponding shape on the fingerboard.

After shaping the fingerboard, I realise the neck part underneath the finger is not long enough to cover the 20th fret...
So I just saw away the neck below the 20th fret to match the sound hole.

The neck to follow the shape of the sound hole.

The fingerboard shape with the 20th fret.

The neck after smoothened with a roller sander.

From the bout looking up to the neck, looks decent even though the neck didn't extend to the 20th fret fingerboard part.

Close up frontal view.

2011-12-15

Glue the back reinforcement

After the inlay what comes next is the gluing the back reinforcement strip.
This cross-grain patch of Spanish Cedar (stable wood) will help to reinforce the back seam
which after the inlay is only at 1mm thick.

No much tricks here just cut to size and glue.
I know some do profile the back strip but I don't as I think the taper at the edge is already very nice.

The only problem is how to clamp the strip
Well I use HHG so it grabs pretty quickly, I just hold until it grabs.
I weight it down with my planes.

The last part I use some clamp to clamp it.
Underneath the seam I support it with my radius stick
Though the back is not exactly fits the stick radius but it's better than having none at all.

Reinforcement strips cut to size.

Measure the thickness of the tail block

Transfer to the strip. But I did leave a bit of allowance for final fitting.

Glue and hold down the strip until it grabs

Final clamping setup.
Not the best but it will do just OK.

The gluing came out fine
I scrape the back and all the tear-out were removed except one which was abit too deep
But more scraping will level it.
Before I close the back I will record the tap tone once more

After gluing. All is well.

Scraping the back

Tear-out almost gone.

Remove part of the reinforcement for fitting the end block.

I saw 4 braces for the back, profile them, and glue them to the black
After tap tuning the back, and shaving down the braces a bit I clamp the lower bout rim to the body and tap the tone.
It sounded quite nice with a nice deep bass.

After sawing the braces, lay them out to see the correct length.
The ends are scalloped.

Profile the braces.

Start to clamp

Clamping done.

Back done with my label pasted.

The back ready to be closed

Tap tune the back. Only the lower bout is active so I clamp it up and tap to hear the tone.

2011-12-09

Inlay the back strip

Well I posted on the OLF and had different opinion on whether to inlay the back strip or not.
For a thing, I like both looks.
The back without the back strip looks nice and the look with the back strip fits the big rosette.
So I go ahead and do the back strip

The back strip consist of 3 alternating tiles same as the rosette: IRW, Bloodwood and Basswood.
I was choosing the router bit for the routing.
And decide on the widest one which is about 12.5mm
Minus the 2.x mm for the thickness of the purfling red / white, it's about 10mm wide tiles.
I use my purfling cutter to cut the correct width saw to size using my miter box.
I cut the red and white fiber using the purfling cutter too with a 1m rule as a guide.
To assemble I use my 2 Aluminium bar to glue the purlfing 1st.
Then I glue the tiles to the 1st purfling and sandwich the other side with the purfling.
I use white PVA as it dries clear and has longer open time.
Anyway I was lazy to heat up the hide glue.

After it dried, I check the looks with the back, with or without.

Checking the looks of the back strip

Assemble the tiles check for the correct width on all tiles and adjust with a plane

Cutting the fiber purfling

Glue the white fiber to the red.

Glued

Clamped.

With back strip

Without back strip which looks better?

When I decide to go ahead, I began the routing setup.
I supported the center back joint part and the sides of back.
They are of different height due to the curavture of the back struts.
But with different scrap they are well supported.
I clamp 2 Aluminium bar to the back to act as a guide.
After adjusting the guide until the router base is at the center of the back along the entire length, I clamp the guide tight and check the alignment again.
Previously I had routed a channel to test fit the router bit and tiles
Then I set the depth using that previously routed channel it's about 1.5mm deep.
The back is about 2.5 so I got some meat left in the back.

After all is set I route it and all goes well.
I glue in the back strip and left it to set.

The 2 Al bar router guide.
Well you guess it correctly it's the same bar I use for clamping the back strip.

Adjusting the bar to make sure it's correctly align using eyeball only :)

Set the depth using the previously routed test channel.

Close up of the depth setting; its about 1.5mm deep channel.

Ready to route

Channels routed; everything went well.

Apply glue in the channel

Glue the back strip into the channel

Clamp tight

After removing the clamp, well... the inlay wasn't perfect.
There are some gaps but I think I can fill it up with IRW dust.
After that I simple plane down the back strip to level but in the process I cause some tearout in the back
Hopefully I can sand it level.

After removing the clamp.

Planing it flush with the back surface

The shavings

Side view can see that it's pretty leveled

Tearout

Gaps...