Funny that Owen should mention outer cases as I'm building
one for an instrument which is going out on rental at the end of the month. My first all iron strung 1x8, 1x4 following the single 8 by Bertarini in Florence. Finally with the long scale there's room for the treble of the 4"
Each time a get around to making the outer case I try to learn from past mistakes. This is so far the most ridgid for it's weight(about 8 pounds with the lid off (I'll let you know what it weighs with the lid)
I like to make the bottom an open frame like a stand and this time I managed to use up one 12" wide cedar plank by
arranging the cheek-bentside-tail in one continuous cut and usining the left overs for the spine and front which is double thick. This time I used 1/4 inch poplar ply with two good sides because the solid wood available was of such poor quality and because of my time limit.The joints are reinforced with cloth tape and fir battens on the exterior.
In order to get the ply to bend in a seep curve without support, I resorted to halk kerfs about every inch on the inner surface. I just finnished glueing on the cheek blocks which are nice light obeche wood (these are the important front corners and they need to be really stiff so there is an angle iron embeded i on each side to hold the front corner square.
If anyone wants more info I can provide it as I build and attach the lid which is supported by steel angles.
Outer cases are tricky to build and can get to weigh more than the instrument. They can also get expensive which is probably why the false inner-outer construction won out.
If I ever run out of gorgeous material for the inner italians.I may have to resort to the inner-outer style.I also like repainting the outer cases every few years an of course it is much safer with the harpsichord in another room.
I've also had pretty good luck attacing lids to plain case italians. So I hope I haven't offened anyone with the mention of plywood which was made by a few builders including Cristofori! Jack Peters