Introduction: Si's Banjolin. in Need of Some TLC.
A Banjolin (or Mandolin-Banjo, in the original form (check history) of having eight strings, in four pairs, in the exact same manner and tuning as a Mandolin (and violin) - indeed, that is what it is - a Mandolin with the body of a Banjo. Great :-)
A cherished three generation family heirloom that has been well-played - with all the bruises and scars to show for it. A friend has asked me (some might say foolishly) to give it some TLC. It's a lovely little thing and I can't wait to play it. I've never played one before, or a Mandolin for that matter but I do bash around on a ukulele so it should be within my reach for a bit of fun. It'll be nice to hand it back, in the hope that it enjoys more use and continues to bring a smile to those in its company.
1) Repair the back of the pot - which had partially parted company with the instrument.
2) Replace vellum/skin - which had split.
3) Attempt to re-shape the rim prior to re-fitting the back.
4) Re-set the nut.
5) General setup. Inc' adjust bridge-height to improve playing-action and notation accuracy.
6) Dress fret-ends to remove sharp edges.
7) Finishing touches (retain character). The bridge situation required a few more coats of thinking about.
8) Restring, spit 'n' polish.
Step 1: The Strip-Down.
First off, were the strings. Next was the Pot back, which didn't need much assistance in coming away, as the rim had warped slightly to an ovoid, which had broken the join. Next, was to remove the head assembly from the pot. All screws and other parts were in good shape, so, no parts to search for.
Step 2: Reattach the Pot Back.
It's fair to say, that the oval warping of the rim posed the biggest problem, both for the banjo, and for me. I attempted to rectify it with clamping for a couple of weeks, gently increasing the pressure over time - I didn't have much luck. Not wishing to remove the character of the instrument by having to reshape and refinish the whole rim and pot back, a compromise had to be made, so I decided to refit the back, as was, and resign myself to a very small offset. I then got creative with pastels and bees wax.
Step 3: Strip the Head.
Firstly, the damaged skin (vellum) needed to be removed, which entailed dismantling the head into its component parts. The old skin, which had effectively become part of the hoop, had to be carefully cut away from it with a craft knife, taking care not to distort the roundness of the open-looped wire ring.
Step 4: Replace Natural Skin Vellum.
Another first for me. I really enjoyed this aspect - from the research, through to the final tuning. An interesting history and some tricky old-school techniques to get to grips with. Fitting the new skin is a sequence of soaking, shaping, stretching and drying, and ultimately, tuning.
A big thanks to the guys at Clifford Essex for the vellum (s). They sent me an extra one, for free, as a practice piece. Luckily, their instructions are so good, that I didn't need it. Just for the record, I used the higher quality of the two skins for the Banjolin and have saved the spare inferior one for a drum project - honest ;-)
Step 5: Reassemble and Refit the Head.
It was clear from the start that the playing action height is primarily set by the position of the vellum, as there are no adjustments available other than with the height of the (floating) bridge which sits directly on the vellum. Taking these points into account, I was anxious to replicate the original setup and thoroughly enjoyed the challenge in the face of a splitting skin - or two :-(
I got lucky.
Step 6: Rebuild.
There appears to be two standard bridge heights. In my opinion, both were too high for the instrument to have a playing action that is both comfortable to play and for it to actually sound tuneful. I don't have an explanation for this and I didn't dwell on it for too long and have no real knowledge of the instrument's history - so I just cracked-on with it until it felt right.
Replacement bridges are only a few quid and I'm guessing that sanding one down to the correct height is within the realms of normality but I didn't want to tamper with the original and couldn't be bothered waiting for one to arrive in the post - so I made one out of a stick and a short length of chunky copper wire.
Always the Heath Robinson.
Polished, tweaked, restrung and tuned.
Goodbye, you quirky little thing. It was nice.