Disclaimer: Always follow safe practices while working with tools. What is safe for one woodworker under certain conditions may not be safe for others in different circumstances. Viewers should undertake the use of materials and methods as shown in these videos after evaluation, and at their own risk.
Making the mold
The Mold design I have given is an outer mould that can allow a one piece neck/body or a separate neck/body to be used.
All my early instruments used an inner mold as used by violin makers, however, I found that when I removed the body from this, there was a tendency for subtle distortion in the form. The same thing is seen in most violins of the baroque period, but not today where symmetrical forms are the norm.
The mold is in three pieces joined by dowels of wood or plastic/metal, this means you can work on the instrument from the top, inserting the linings and then remove sections and add linings to the bottom without full removal. (see videos for demonstration)
I use MDF(medium density fibreboard) which comes in 12mm thickness's in the UK, My earlier inner moulds were of wood.
Note that the space for the neck is at the larger end of the spectrum, so you need to insert a couple of pieces of veneer/card for less wide necks.(Or modify your mould accordingly)
The best way to make the mold is to work on getting one layer smooth and then using it as a master mould, setting up your router on a router table to copy the form.
This next video is an update to the first two videos about making the Mold, Since I drew the plans for this back in 2006 I have made some adaptations: The insert made with wood glue needed improving, while it was a nice touch to use waste material to make a soundhole insert, in practice it was a pain and only worked with adhesive that didnt shrink,The second part of this video shows the fitting of the mold with nut inserts so that it can be used as a clamp to hold the top and bottom during gluing, a fantastic idea! I have taken from the Ukulele maker Pete Howlett(many thanks for sharing this)
Petes great ukulele making series:
If you are using the mold to glue the top and bottom at the same time then you need to make the top sections of the mold in 2 pieces.
(Therewas a year inbetween the last mold making video(1.2) and this one, I actually forgot that I was going to make the top sections of the mold split in two and during gluing up I discovered my errror and had to cut open the mold with an instrument inside!! If you watch the videos in order you will avoid my mistake. I wish I had a film of my reaction when I realised my blunder, would have made a good outtake for the DVD extras.......lol