Hi everyone . An old Gibson mandolin has come in which needs a little work . Its pretty straight forward but I don't have much experience with these . It seems to be around 1913 so its the oldest instrument Ive worked on . The back has a wide crack as it wasn't quarter sawn , and is separated from lining also . I think I will have to glue and clamp the cracked area back into shape as well as possible and then glue in a strip of veneer wood into the crack to fill it . Does this sound ok ? Titebond or fish glue might be in order as it is awkward . I will do Frank's brace glue-up too . Also once its done , what should I clean the lacquer with ?Note the spool clamps are just acting as feet .
I would humidify it to close the crack as much as possible, then add a splice if needed. Personally I would use hot hide glue for the repairs and splinting.
for cleaning I would do the minimum, maybe a wipe down with warm water and a touch of dish soap. Naphtha will be ok to use for serious cleaning if needed.
I’d stay away from serious polishing to keep the present patina.
Thanks Jim your input is valuable here , I didn't consider humidity because we are between a large lake and the sea but its definitely worth doing . Do you know what woods were common for the back ? It looks rather plain but has strong silk rays in the crack .
Most Gibson A mandolins were birch, but maple would be ok for a splice too, a wood color that closely matches.
if you use Naphtha for cleaning experiment first in a small spot to make sure it doesn’t effect the finish.
If it’s 1913 wouldn’t the finish be varnish? If so, cleaning it might be different than with lacquer.