There's a buzz

I thought I'd finished restoring the Zither Mandolin Banjo and gave it a quick strum and twang. There was a noticeable buzzing sound. After a bit of prodding and poking I found I was able to stop the rattle by pressing down on the part of the tailpiece that overlaps the edge of the pot. It could just be the angle of the bridge but there was also a little gap between the top of the pot and the top of the tailpiece from where I'd sanded the rim flat after regluing it as the tailpiece was still using it's original screw holes.

Looking online it seems the usual remedy for rattling strings at the tailpiece is to add a little strip of leather between the rattling surfaces. Whilst that's usually it's between the strings and the metal I suspect it'll work between the metal and the pot if that's what's rattling. I think the pressure from the strings will probably squash it flat. So, I popped to Hobbycraft and got some leather chord, it took ages to find as it was in the jewellery making which unsurprisingly I'm not very familiar with. I cut two strips the length of the overlap then as it was a natural beigey colour which didn't match anything on the mandolin I coloured them black with permanent marker. After undoing the strings and loosening the pot bolts I removed the head again and undid the tailpiece nuts.

I tried putting the leather onto the pot then attaching the tailpiece but it kept falling off. In the end I inverted the tailpiece, sat the leather in it then held the instrument upside down and pressed it to the tailpiece and held it in place whilst tightening the the nuts and bolts.

Replacing the head I swapped out one of the brackets that was a little long for a spare I'd made that was a better fit -well metalwork evidently isn't my forte, set the pot bolts, popped the bridge on, restrung it and tuned it again. There was a bit of a buzz still but tweaking the angle of the bridge sorted that out. I may need to sand the foot of the bridge at some point if it keeps moving but for now it's playable.

Reattaching Neck and Tailpiece

Having painted and sealed the pot it was time to reattach the neck, tailpiece and the stud at the back which nobody seems to know the purpose of.

I wound up having to use a hammer to get the stud back into place, this damaged some of the woodfiller on the inside so I had to stop and fix that then spray over that. Next up as the tailpiece.

I'd've liked to have electroplated the tailpiece again as the presumably nickel was rather worn but finding a couple of pieces of pure nickel to use as anode and cathode proved impossible locally and too expensive to order online so I gave up on that. The tailpiece is in two parts, the piece the strings attach to which is all the majority of Zither Banjos and Zither Mandolin Banjos I've sen online have and a second piece of metal which goes between this and the wooden pot. The large metal bracket appears to be there to maintain the shape of the pot against the poll of the strings. I've seen this on one other banjo I've seen on the net. Using a small flat headed screwdriver and an adjustable wrench I replaced both parts. They still fitted the original screw holes despite my having reglued the pot. There's a gap of almost 1mm between the top of the pot and the edge of the tailpiece from when I sanded the rim flat again.

Using a  right angled torque screwdriver I reattached the neck. Messing about with difficult to reach slotted screws gives you a new appreciation for the crosshead screws.