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Jameel
Oud Junkie
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That seems like a very tedious way to bung the pegbox, j. I've used both side grain and end grain plugs, the latter simply being old pegs that I glued
in place them reamed. The problem here the grain direction. The pegs will sink in more because the grain in parallel with the peg's grain. It works
though. You would have a much easier time drilling if you plugged the holes in the pegbox first, then drilled and reamed. Break out is not a problem
if you drill carefully, and start with a small bit, so any breakout will be removed by the reamer. The absolute best way to plug old holes is to take
a heavy plane shaving of hard wood like box, saturate it with glue, and wrap it around a tapered rod of steel or other non-gluing material in a
spiral, insert into the hole until its tight, wait for the glue to dry then remove the rod, then ream. The hole is now made up of long grain fibers
all around the hole, this provides the best wear surface, since there are not areas of alternating grain (end merging to side grain) as in a typical
hole.
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jdowning
Oud Junkie
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Thanks for your suggestions and comments Jameel. At this point in time I have just been testing the possibilities without committing to action yet -
so am still open minded. The production of the boxwood 'bushings' should not be so time consuming compared to the alternative of having to make dowels
and then hand cut them into tapered plugs using a peg shaper (I do not have any old pegs to use for plugs). The pre-drilling of the bushings is also a
fairly quick operation. I am convinced that the bushing procedure will work satisfactorily.
My main concerns with this method are that - because each bushing is tapered on the outside, they must all be inserted into holes reamed from the
outside faces of the pegbox inwards. This means that after installation each pair of bushings will have been inserted in opposite direction to each
other with their external tapers also running opposite to each other. However, the external tapers will guarantee a close fit (and good alignment) of
each bushing in the pegbox so I think that - once glued in place - it is unlikely that any will 'pop out' in use. I am more concerned about
undertaking a pegbox repair that may be non traditional - one that could be considered to be irreversible once the oversized holes for the bushings
have been cut.
The question of wear of the bushings may not be so much of an issue given that the refurbished pegs are all made from a softer material than the
boxwood of the bushings.
If I decide not to proceed with the use oversize bushings after all and revert to using tapered peg shanks as you suggest I would probably make them
from walnut to match the sides of the pegbox outer faces.
What do others think? Are there any ouds fitted with oversized peg bushings or collars - possibly made from bone or other hard material of contrasting
colour to the pegbox sides making them a decorative as well as functional feature? All comments welcomed.
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jdowning
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Having just almost completed another non oud restoration project that has been waiting for 6 years for attention (or so my wife reminds me!), I can
now resume this thread.
I have decided to proceed with the pegbox bushing option as this - if it works, as I am confident that it will - may be a useful alternative repair
for future projects.
Today I prepared a batch of boxwood bushings using a 3/8 inch Lee Valley taper plug cutter. The bushings were pre drilled to minimum diameter of my
peg reamer.
The pegholes in the pegbox were reamed out to almost the maximum diameter of the peg reamer - first from one side then the other - keeping the reamer
aligned concentrically with the opposite peg hole throughout. Each bushing was precisely fitted to protrude a little on each side of the pegbox sides
- for trimming to size later.
Use of bushings helps to remove much of the damaged, splintered wood around the original pegholes.
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jdowning
Oud Junkie
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The attached images show initial progress in fitting the bushings. The bushings protrude a little on each side ready for later trimming flush with the
sides of the pegbox but at this stage have not been glued in place.
To stabilise the pegbox assembly during the reaming operation the original damaged pegbox backplate (due to be replaced) remains in position (with
open cracks temporarily re-glued where necessary) and the new pegbox endblock - as yet untrimmed to final size - has been glued in place.
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jdowning
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All of the boxwood bushings are now glued in place ready for trimming. As the bushings are cut on end grain, I first trimmed away excess material from
the bushings using a saw.
I first tried using a Japanese style flush cutting saw (used on the pull stroke) which has the teeth set on one side only to prevent cutting the
pegbox sides (Lee Valley Tools cat# 05K34.01). This worked fairly well but tended to 'ride up' in the cut leaving more material to trim away with a
chisel than I wanted.
The remaining material was then cut away with a paring chisel (lapped perfectly flat on one side) until flush with the sides of the pegbox.
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jdowning
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I then tried using an XActo razor saw with the metal backing strip removed. The saw blade is only 8 thousands of an inch thick with very fine teeth so
was used on the pull stroke. Masking tape was wrapped around one end as a temporary protective grip. Strips of masking tape were positioned on either
side of the bushing to be cut to protect the sides of the pegbox from being scratched by the saw teeth. This worked quite well leaving minimal
material to be pared away with the chisel.
Then the sides of the pegbox were filed (using a flat, medium cut machinists file) to remove most of the old scars, undulations and other
irregularities as a preliminary to final finishing later.
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jdowning
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The bushings were not large enough in diameter to cover the original splintering around two of the pegholes so the remaining damage was filled with a
touch of glue mixed with the sawdust from filing the pegbox sides. The filler will dressed flush with the pegbox sides once the glue has fully
hardened.
This is the outside of the pegbox after filing.
The next stage will be to trim the bushings in side the pegbox. As the damaged pegbox backplate is to be replaced, the bushings will be trimmed once
the the old backplate has been removed allowing easier access.
Reaming of the bushings and fitting the pegs will be undertaken once the new backplate has been installed.
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jdowning
Oud Junkie
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Moving on to prepare the new pegbox backplate.
The blank for the backplate has been cut from a piece of 19th C American walnut on my bandsaw - a 14 inch Rockwell Delta fitted with a 'Viking' 1/2
inch blade, 3 teeth per inch (Lee Valley Tools cat #02j04.93 - no I am not a shareholder, they just sell good quality product!). This is the only
power saw that I have in my workshop and is used for all of my woodworking projects. It is set up so that I can accurately cut veneer to less than 1mm
in thickness - up to 6 inches wide, if I want. One of the most important factors in setting up a bandsaw is correct blade tension. If blade tension is
too low the blade tends to bend backwards under pressure of the cut and will distort causing the blade to 'run out'. The blade tensioner on my bandsaw
is theoretically calibrated to handle up to a 3/4 inch wide blade but - at that setting - the tension is far too low (the wider the blade the higher
the tension required). I have found that with the blade tensioner set to maximum a quality 1/2 inch blade is just about the widest that the machine
can handle.
The blank shown in this image is hand planed on one face before sawing, and is just over 1/16 inch (1.5 mm) thick.
The saw marks are then removed by hand planing. I use a small block plane with an adjustable throat finely set. The blank is clamped first at one end
to a flat pine board, planed, and then reversed and planed in the other direction to complete the process. The blank is then finished with a cabinet
scraper to remove any planing marks and reduce the blank to the required thickness.
A cabinet scraper does not actually 'scrape' but planes a very fine shaving. In this type of scraper the blade is first ground and honed to a bevel -
like the blade of a hand plane. The edge of the sharpened blade is then burnished or polished with a hard steel rod. This turns the razor sharp edge
of the blade into a hook shape which is the shape required for the cabinet scraper to function efficiently.
Measuring the thickness of the completed blank I find that it measures only 50 thousands of an inch whereas the original measures 73 thousands of an
inch. So - I must repeat this operation and prepare another blank of the correct thickness. Not a problem - I do not make instruments for a living!
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jdowning
Oud Junkie
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The old damaged pegbox backplate was removed by brushing hot water along the glue joint inside the pegbox and using a hot iron to soften the glue. The
surface of the backplate inside the pegbox had no varnish finish so the water quickly soaked into the joint. Transverse burn marks were in evidence on
the backplate.
With the backplate removed the interior of the pegbox was cleaned up, bushings smoothed over with a file and the new end block trimmed to size all in
preparation for final finishing.
All old glue was removed from the backplate glue joint with a stiff cabinet scraper blade. This also levelled any irregularities in the joint.
Removal of all of the old glue is an important part of preparing the joint.
The scraper blade is sharpened differently from the blade in a scraper plane. The edge is first filed straight and square and then honed on an oil
stone to produce sharp 90 degree edges on the blade. The two edges are then burnished over with a hardened steel rod - each to an angle of about 10
degrees - to form a hook shaped cutting edge. Correctly sharpened and prepared a scraper blade will shave off very fine shavings - cutting not
scraping.
The replacement walnut backplate blank is finish thicknessed slightly oversize to 0.078 inch and cut roughly trimmed in readiness for bending to
shape.
The original finish on the backplate was tested and appears to be spirit based (shellack?) covered with a thick protective coating of a wax polish.
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jdowning
Oud Junkie
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The new backplate will be hot bent, using a bending iron, to fit the curves of the pegbox. While I am at it, I shall also make a caul - hot bent from
1/4 inch thick plywood - for gluing the backplate to the pegbox.
For those interested in making their own lutherie tools here is my bending iron easily made from scrap material - not pretty to look at but it works,
has a wide range of heat adjustment and is versatile with large heat capacity. It is made from a piece of thick walled copper pipe that has been
pressed to an oval shaped section in a vice and bolted to an iron support bracket. Three layers of asbestos cloth have been used to insulate the
support bracket from the heat of the iron. A few spacing washers to create an air gap would probably work just as well.
A small propane torch has been mounted on the support bracket using a standard cable clip. This allows the position and direction of the flame to be
adjusted for heat control.
The bending iron could also be made from other materials such as steel or aluminium pipe.
As the heat source is a propane torch, this style of bending iron should only be used in the vertical position to avoid flame instability and danger
of 'flare ups' caused by burning liquid propane.
This bending iron is a heavy duty tool more than adequate for bending veneers a few millimeters thick but can just about handle plywood or other
thicker materials where a lot of heat capacity is required.
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jdowning
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The walnut backplate and matching glue caul in 1/4 inch thick plywood have been bent to shape on the bending iron. Here they are being tested for
correct fit - a dry run before gluing - using some small fast action clamps picked up at the local dollar store (thank you China!). I shall need to
make a few minor adjustments for a perfect fit.
The backplate will be glued in place with hide glue. Hide glue is the most versatile of glues and should be used for instrument construction and
repair wherever possible. It is relatively cheap, non toxic, has an infinite shelf life in its dry granular form if stored properly, it can be strong
with short 'grab time' but can be diluted to vary strength and set time as required, it can be remelted with heat and humidity and it does not stain
wood. It is commonly available in two strengths a very strong brown coloured 'granular hide glue' with fast grab time and a purer, clearer 'pearl
hide' glue that is weaker with slower set time. I prefer to use the latter where appropriate.
The glue granules after being just covered in water and allowed to soak overnight are then heated and stirred to melt the glue using a water bath to
keep the temperature of the glue below 140 F. Above that temperature the glue will spoil.
When I attended general woodworking classes at school in the early 1950's we used only hide glue heated in cast iron, water jacketted, glue pots -
the pots being kept bubbling away all day so that glue was always ready when needed. I still have a couple of these that I keep as souvenirs of times
past. Today, I simply put the glue in a small clean glass jar - only as much as I need for the work in hand - and put the jar in a saucepan of boiling
water on the stove to melt the glue. I do not bother to check the glue temperature - I suppose that I should but life can get too unnecessarily
complicated. Once made up, the glue will not keep for more than a week so I just make up a fresh batch when needed and throw out the old stuff.
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jdowning
Oud Junkie
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The new pegbox backplate has been glued in place and trimmed ready for shellacking. Before gluing, the end grain of the new pebox end block was sealed
by coating with hot glue and immediately searing the glue in place with a hot iron. I decided not to use the plywood glue caul as I was not able to
work quickly enough during the gluing operation. Instead I worked my way along the backplate reheating the glue with a hot iron and clamping as work
progressed.
I prepared the shellack by covering orange shellack flakes with about three times their volume of methyl alcohol in a 'mason' jar with a sealed lid
(to prevent evaporation of the fluid). This mixture was allowed to stand for two or three days until all of the flakes had dissolved. The white
sediment (impurities) at the bottom of the jar was discarded by decanting the clear shellac through a cloth filter.
The orange coloured shellack is good for coating dark woods and providing an 'antique' finish that hopefully will match the original finish of the
oud. The shellack is used very dilute so can be applied with a brush but many coats will be required - I am in no hurry! Normally, brush application
of coloured varnishes is difficult and requires a lot of experience to achieve a consistent finish. Using the orange shellack at high dilution -
although fast drying - avoids this difficulty. I will apply one coat each day - to ensure each coat is fully dried - with very light sanding between
each coat - sufficient only to remove any dust particles or other imperfections.
Once the shellacking is complete I shall fit the pegs. The original pegs have been refinished with a penetrating black stain. In common with other
luthiers like Jameel and Richard I prefer to use India ink - readily available from office supply stores. This ink is made from lamp black which
provides a dense opaque finish unlike stains made from analine dyes that tend to be translucent and show the wood grain. The peg heads will be further
sealed with a shellack coating.
Both the shellacking and peg fitting operations will be carried out with the pegbox detached from the oud for convenience and ease of handling.
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Ronny Andersson
Oud Junkie
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John any update on the project?
Best wishes
Ronny
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jdowning
Oud Junkie
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Hi Ronny- thanks for your interest.
To update everyone, the project is still very much alive with the pegbox undergoing many coatings of shellac and the pegs stained and ready to be
burnished and fitted. More on this later. I shall split the rest of the work into two more sections - the soundboard and the body - so that I might
carry out the operations in parallel and keep everything manageable (I only have a dial up connection so uploading data can get very slow)
Among other things, I am currently very much involved with local museum projects - restoration work, demonstrations, historical displays etc. - so I
have to spread my 'spare' time in retirement accordingly. I also have two lute recital/talks scheduled for this summer season and have had to switch
priorities to rebuilding one of my lutes (and refurbishing its fitted case) for use in these events. This work is now almost complete but I had hoped
to have finished work on the oud as well because I plan to incorporate this instrument in my talk which deals in part with the history of the lute and
its music. As things now stand I shall likely still make use of the oud even in its partly restored state.
Regards
John
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jdowning
Oud Junkie
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The final stage in this part of the restoration is the fitting of the pegs. This was done with the pegbox still detached from the neck for
convenience.
Using a violin peg reamer the bushings were carefully reamed out to size - ensuring that the reamer was kept in true alignment with both bushing
holes.
In this case the reamed hole at the tail end of the peg was found to be slightly oversize (possibly due to the way the blade of the peg cutter was
set) - but this is what I want anyway. The objective here is to make the fit of the peg at the peg head end slightly tighter than at the tail end of
the peg in order to minimise any twisting force along the peg shank that could cause destructive damage to the peg. The best fit is judged from the
markings in the bores of the bushings (left by the staining of the peg) which should be heavier at the peghead side than at the tail of the peg. The
refurbished original pegs - of rather poor quality - are of softer material than the pegbox, so will bed in faster. To achieve this fit the peg holes
were reamed until the peg had entered the bushing at the narrow end about half way and then the burnished section (the shiny bit) at the peg head end
was - little by little - carefully reduced by rubbing with a strip of fine emery cloth until the best fit was achieved.
Once all pegs have been fully 'bedded in', the pegs will be finally trimmed evenly at the tail end and the cut surfaces restained.
One of the pegs at the tail end of the pegbox was found to have been previously damaged by twisting of the wood fibres. This was repaired with a
couple of drops of "super glue" that were allowed to soak into the damaged area consolidating the fibres and bringing the peg back to full strength.
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jdowning
Oud Junkie
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I should mention that the reaming of the pegholes should take place after the sides of the pegbox have been varnished as the varnish that soaks into
the bores of the bushings is then removed during the reaming operation.
I shall probably need to drill some new string holes in the pegs where the original holes no longer fit.
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SamirCanada
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Any updates Sir John?
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