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process, because hide glue has a use-by date, and I was half-way through before I read the bottle and found it was out of date by six months.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 🙂

mandolin bindings

mandolin bindings

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!



And so to bending the sides. You will recall I made a luthier’s bending iron from a piece of water pipe and a heat gun, well here it is in action bending the sides, or bouts of the mandolin.

The first bend was the upper bout for the top quadrant to the right of the neck – this would be the least conspicuous if I made a mistake.

I ensured the bending iron was at the right heat – so water misted onto it boiled immediately

luthier's bending iron

I had the bouts soaking in a tub of water for about 20 minutes. They had been thinned to just under 2mm with the wasp sander mounted on my drill stand. They probably needed to be a little thinner still – more like 1.0-1.5mm thick for easier bending.

Once the iron was hot enough I donned leather welding gloves – so my fingers wouldn’t get burnt if I made a mistake – and picked up the bout and the metal bending sheet that I had made earlier. The bending sheet provides support to the fibres of the timber and helps to hold the steam in the wood. I’ll explain in a moment how I made the backing strap.

luthier's bending iron
I gently worked the timber, springing it slightly and pressing with a wrapping motion against the bending iron. You can feel it reach the right temperature and the point at which it wants to bend. Don’t rush this because – as I found – if you try to go too hard too quickly you will snap the timber and have to start over. It’s best to have a test piece or two so you can practice first on a non-critical component. Here is another view of the process.

luthier's bending iron

Within about two hours I had all the bouts shaped and clamped to the body so they would dry and retain their shape. Blackwood is notorious for springing back to its original (flat) shape. I left it overnight to cool.

The bending iron worked well. I would get it really hot on the 600C setting then when it reaches operating temperature I dialed it back to 300C to maintain heat without stressing the heat gun too much.

Making the bending strap
The strap is quite simple to make. you need an empty steel food tin (washed carefully) with the top and base removed. I cut it open with tin snips/shears. Next I took two small size tent pegs and bent them in a vise into a triangle – these will form the handles so you are not dealing with a sharp tin amidst the heat! I folded the ends of the tin can around the tent peg on the side where the two ends meet, and hammered it so it made a good round shape around the tent peg, leaving about a centimetre (say half an inch) and drilled three holes and joined it with three pop-rivets. Complete the other end and voila – you have a luthier special tool bending iron backing strap!

luthier bending strap

Tomorrow is glue-up time!


Things are progressing well now. Having made the end block from maple out of a tree that burnt at home during the 2003 Canberra bushfires I glued the top and back to the end block and set the neck in place. The neck is a unit with the heel block and has slots cut in the sides for the upper bouts. These will be bent from Tasmanian Blackwood thinned to 2.0mm with the wasp sander.

So the state of play is illustrated here. The fingerboard is yet to be glued in place.

Mandolin neck

Mandolin neck

I decided to go with a cross bracing because by all accounts it is best suited to the single sound hole, provides good rigidity and brightness, and plays in rapidly.

I used straight-grained pine for the braces as this seemed to be closest to bass wood that I had in my shop at the time. I thinned the tops of the braces and cut a cross halving joint to connect the intersection. I also added a brace next to the sound hole for extra rigidity and glued them in place with hide glue. I used that glue because it is acoustically transparent – it doesn’t interfere with the sound.

I tapped the top and reduced the braces to achieve a tuned plate at G, reasoning that this would give a good bass response.

Here is the bracing pattern. I may add another brace at a later point if it needs it for structure

mandolin cross bracing


Armed with a bending iron and not afraid to use it, I set about shaping the linings to fit the top and back. I had prepared the timber (pine slats) by cutting kerfs and then cutting the linings in half along their length to make twice the length for half the effort.

I soaked them for about an hour in a large tub of rainwater, and then measured them up ready for bending.

I turned on the heat gun and waited a couple of minutes to ensure the pipe got really warm on the 600C setting, and set to work.

using a luthier's bending iron
I did the linings in sections so that complex curves were kept to a minimum, and left room for the end and neck blocks.

The linings were then clamped in place held by clothes pegs and allowed to dry so they wouldn’t spring back which would make gluing more difficult.

And here is the result.

mandolin linings

mandolin linings


After roughing out the neck, I set to work with a plane and scraper to smooth out the head part of the neck. This is quite time consuming, so progress this week has been fairly slow – but it is definite progress.

To give some idea of the current status, this is the neck so far with the fretboard placed (not yet attached) in position


And to provide some context, this photo shows the relationship of the components



It has been a productive weekend. Having brought the ribs, or sides, to the right thickness, I rubbed on some orange shellac which really brought out the flaming in the Tasmanian blackwood.

The next task is to make the linings – these are backing pieces which help to attach the sides to the top and back, and also give a broader gluing area for the top and back. These important structural components need to be fairly robust, yet be flexible enough to be able to be bent into the shape of the mandolin. To achieve this, kerfs are sawn into the linings at regular intervals, so that the wood is cut, but not cut through.

This results in a flexible snake of blocks connected by a thin timber, which can then be steam bent into shape. They are much larger than those for a violin, as they help to provide extra rigidity to the instrument, and that is supposed to help the sustain. They also need to be large enough to provide gluing area for the sides – even after the sides have been cut away slightly to allow for the binding veneers.

I clamped a stop block to the scroll saw and was able to make the kerf cuts quickly and evenly, as shown in the photo.

You can read the rest of the story here:
Part 1 – making a start (selecting the timber)
Part 2 – preparing the top
Part 3 – cutting out the back
Part 4- starting the ribs
part 5 – sawing the ribs
part 6 – thinning the sides

making a travel mandolin – part 7 – kerfing the linings.