a single mandolin string repeatedly going sharp

[Bob Laughlin]

has anybody had this problem? - a recent mandolin i built has a problem i've not encountered before - one of the A strings goes sharp within a minute or 2 of tuning it - consistently - the other A string stays right on pitch as do the rest of the strings - i've changed the string to no avail but have'nt tried a new set of tuners yet (stewmac golden age)

what could cause such behaviour?

[Greg Mirken]

It almost has to be the string binding in the nut slot. When you tune up, there's more tension between the nut and the tuner, which pulls a little string through as you play. Try reshaping/smoothing/lubricating the slot.

Or, you might be perilously close to a rift in the space/time continuum.

Greg Mirken

[Dale Ludewig]

nut slot probably is my guess also.

[Rolfe]

nut slot my guess too, but rift in the space/time continuum should be investigated

[Steve Etter]

+1 on the space/time thing.

[Nelson Peddycoart]

I am having a similar problem. I told my wife that I needed to stop by Home Depot to get some dry graphite before meeting her for dinner the other evening. She asked why. I said "I need to lube my nut." She gave my a funny look and after a minute said "O.K....Which instrument?"

She is catching on....

[Bob Laughlin]

of course - it seems obvious now - what else could it be!
thanks to all - bob

[allenhopkins]

Nah, I like the "space-time continuum" theory better. Are you missing any socks? These disappear through the rift into a parallel dimension. In exchange, we receive wire coat hangers -- at least that's what they appear to be in our universe.

[Big Joe]

In the space-time continuum concept, you should also check the slots on the saddle to see that the string is not binding there also. Just like nuts, they need to be checked as well.

[Ivan Kelsall]

Nice to see that old & very amusing thread rearing it's head once more Allen - wire coat hangers - i love it !!,
Ivan

[danb]

I had a similar problem from slightly raising string gauges.. I used 400 grit paper folded in half and widened the nut slots a hair for my a strings. a little graphite from the tip of a pencil also sort of helps as a temporary measure, but really you want a nice hard nut (mop or bone) and nice smooth slots

[Bob Laughlin]

i believe the problem (string binding in nut groove and going sharp later) started after i tried the baking soda/cyanoacrylate glue fix to raise the nut action (laziness) - this seems to work on wound strings, either guitar or mandolin, but not so well with unwound strings esp. smaller guages - i think

[fishtownmike]

I would check the F hole. Nah just had to say something since everyone else mentioned the nut or bridge saddle.

[MikeEdgerton]

Nuts.