January 10, 2009
After gluing on the fingerboard and nut I touched up the varnish and gave the whole instrument a good final cleanup and wax.
Then it was time to add the tailpiece and machine heads and the instrument was almost finished.
The final-ish thing was to make a bridge – I used some leftover Tasmanian Blackwood and made a bridge, tuning in the strings with stepped forward and back slots.
Finally I got some new strings and strung it up for the first time. It needs playing in but the sound is wonderful and will only get better!
You can read all the steps here
This was very well worth doing!
Here are some more photos
And here is what it sounds like
January 9, 2009
The sides glued up well, and progress continues – after removing the clamps I gave the sides a quick clean-up with sandpaper to remove glue squeeze-out. Titebond liquid hide glue is great to work with, allowing some slip time to get everything lined up ok, but then once it starts to bind it holds well and dries within a few hours.
The mandolin is now starting to look like an instrument, but it is still fairly rough around the edges. The binding provides a decorative border, but also provides additional strength and protection for the joints. I have been quite worried about the gluing process, because hide glue has a use-by date, and I was half-way through before I read the bottle and found it was out of date by six months. Apparently Titebond put a 12 month use-by date on, but liquid hide glue can last 12-18 months. Perhaps I was lucky this time. But if any components fail I will be buying a new bottle forthwith. I could use the hide granules, but that would involve messy use of double boilers and rushing to use it before it cools etc. The liquid glue is very easy to use, is versatile at room temperature and works well.
Anyhow, I had bought some inlay banding strips at the 2008 Canberra Timber and Working With Wood show with a view to their potential for instrument bindings. The banding strips are about 1.5mm thick and about 6mm wide and 1.2metres long. They are easy to use, being flexible enough to do each of the bouts without steam bending, and thin enough to cut easily with a sharp knife.
You’ll have to wait to see how it looks, as they are still taped in position after gluing, but the early indications are good :-)
The next pictures won’t look much different as I still have to add the bindings for the back/bout interface!
The small round piece of blackwood in the foreground will become the back button, concealing the two pins that help to locate the neck – but more on that tomorrow.
I basically have the back bindings, fitting the fingerboard and some finishing work on the head before fitting it up ready to play – so not long now!
October 19, 2008
I was having a look at some luthier sites the other day and came across Mandolins by Peter Coombe, and thought it would be good to review a local Australian luthier from Canberra.
I’ve seen and admired Peter Coombe’s mandolins at the National Folk Festival – they have a beautiful sound, and look great – making excellent use of Australian timbers, such as Tasmanian myrtle and Queansland maple.
He has an extensive website, and with the high quality sound and finish on his instruments, it is no wonder there is a two year waiting list. He works with his clients to identify what type of sound and what timbers would best suit the individual. You can hear sound samples of his mandolins on the website.
I particularly like the detailed step-by-step construction process he has on the website so you can see how your instrument will be made. It is also a great help for the novice maker such as myself, to see how certain aspects of the construction should be done. And I like the refreshingly honest way he describes how construction doesn’t always go entirely smoothly, and how to adjust things if there are minor mistakes, or flaws in the timber.
I also like the way he deals with the sensitive issue of rare or endangered Australian timbers, such as King Billy pine used on his Goldfinch series – that such timber is not to be wasted even if there are minor flaws – the occasional visual blemish must be tolerated as long as tone isn’t compromised – and after all it is the sound that sets Peter Coombe’s mandolins apart from the Korean factory imports.
If you are looking for a superb instrument with the distinctive look of Australian timber, then I highly recommend checking out Peter Coombe’s mandolins. And check them out at the next National Folk Festival if you are in Canberra around Easter time.
October 1, 2008
I mentioned that at the recording studio I had to do some impromptu raising of the bridge by inserting strips of cardboard beneath one foot to stop a slight string buzz. Well, back home I decided to fit a new bridge. When you buy a bridge from a music shop you will notice that the feet are quite large and the profile is slightly thicker than you might be used to. That is because the bridge needs to be fitted to your particular instrument. But it is something you can do yourself.
Step one – fitting the feet
You can see how the bridge’s feet are flat, but your violin has a curved or arched top. So your first task is to shape the feet to the arch. If you have a belt or drum sander you can get close very quickly, but that is not recommended for the beginner – you can take off too much wood too quickly. So just get a small sheet or disk of 180 or 360 grit sandpaper and lay it on your violin top – with the abrasive side up! Then loosen your strings just enough so you can lift the bridge with some effort (this is so you don’t take all the pressure off and possibly dislodge the soundpost). Now slide the sandpaper underneath and holding the bridge you can either move the bridge a little against the sandpaper taking care to keep the bridge vertical so you don’t round off the feet, sand the bridge until the feet match the profile of the instrument. The other way to do it is to hold the bridge still and move the sandpaper. Be patient – it takes time. But what you are aiming for is to match the feet to the instrument so there are no sound losses.
Step two – the top profile
You will see in the photo above that there is a pencil line and markings for the proper position of the strings. I just used the old bridge for a curve template, but slid it up a little because I wanted to raise the string height a little. I then sanded down to just above the profile. This is deliberate, because at this stage I haven’t cut V-notches for the stings to ride in. The important thing is to get the profile about right by refitting the bridge and trying it for string height. If it’s too high, make a note of it and reduce the profile slightly and try again.
You will also see in the picture above, that the bridge is still a bit fat. So take the bridge out and lay some 360 grit sandpaper on a flat surface – and reduce the thickness overall using a circular or figure eight motion.
Now using the old bridge as a template, mark where the strings should go – or if you have Bruce Ossman’s book use the bridge template in there. And using a Stanley knife or sharp knife gently notch the top at the pencil marks to about half the depth of the string, and make them a V-shape so the string beds in nicely without sideways movement. These are at most half a millimetre – so it’s not much – but now you know why you sand down to about half a millimetre above the pencil line. So you are nearly there. Just erase the pencil marks with a light sanding.
Step 3 – Thinning the top
In order to impart the string vibrations to the the bridge, without the thickness of the bridge dampening the sound, there is just one more step. What you will do is to taper the bridge profile on the side nearest the fingerboard. Again, it’s a bit more sanding, but in the end it’s probably not much more time involved than it has taken to read this post – and you have the satisfaction of being able to interact more intimately with your violin! This photo shows the taper – and the finished bridge installed. Tune it up and hear the difference :-)
March 13, 2008
Looks like a great exhibition coming up for anyone heading to California… Violin making in America – a celebration of the luthier’s craft and technological innovation – including electric violins from the 1930s, and all the different shapes that violin makers have tried in their quest to improve on the centuries-old design.
And violins are nothing without a bow – so the exhibition also includes a large selection of bows too!
February 21, 2008
Once the glue had dried I removed all the peg clamps and used a pencil to draw around the outside of the ribs onto the material for the back.
By keeping the pencil flat to the ribs this means that the line would allow a little overlap beyond the ribs – this will help to protect the ribs from knocks when the fiddle is assembled.
After cutting out the shape roughly with the hobby bandsaw I set it in the vise and positioned the hollow rib frame over the board. Again using a pencil I roughly outlined a dish shape inboard of the blocks and leaving a little margin for the edges so that there would remain a flat lip for gluing the back to the ribs.
Using great care and loads of protective clothing – canvas apron, earmuffs, dust mask, visor and gloves I gently scalloped the dish out with the Arbortech Woodcarver blade mounted in a standard Ryobi angle grinder. And I mean gentle – that blade can take off a load of wood very fast if you are not well braced and well balanced on your feet.
Then a bit of leveling with hand chisels and finally dressing with a curved scraper. This latter is a wonderful tool that gives great feedback and you can scrape along or across the grain with impunity.
By the end of the evening I had the first phase of the back almost done. The next thing will be to thickness it down a little and then shape the convex surface close to the interior contour. The wood already has a ring to it – it’s amazing how you can hear the acoustic properties change as the scraper is drawn along the timber.
February 10, 2008
With the glue dry on the ribs it was time to separate the skeletal structure from the mold ready for the next step – lining the ribs with reinforcing strips to provide a greater glue area for the top and back plates.
This is essentially the same process as for the ribs themselves – soak some thin timber strips for about half an hour and then heat up the water pipe in the vise and with the tin backing strip, steam bend the linings at each end – I’m not sure if Neil Gow did it this way or if Antonio Stradivarius used this technique for his violins, but the concept of lining the ribs goes back a long way into the history of violin making.
I then clamped the strips in place against the inside of the ribs to dry so they would retain their shape. I held them in place with clothes pegs and a couple of spring clamps for the ends.
Here are some closer views.
The next step is to glue these firmly in position and clamp again until the glue sets.
After this I’ll shape the end blocks and start work on the top and back plates.
For previous entries on this topic see:
Pochette part four
Pochette part three
Pochette part two
Pochette part one