Could y'all just give me a second opinion on an action issue?

[belbein]

I've been away for a while, dealing with trivialities. Now that I'm back, I'm unsure that I'm thinking through this thing right, and just want some back-seat-driving.

The deal is: my Weber Mandola has always been lovely to play: it has a very light action, which is the way I like it. A few days ago--after all the cold weather in the past few months--I picked it up and found that it has a problem. The problem is that while the 1st (A), 3rd (G) and 4th (C) courses are their usual mellow selves, the 2nd (D) course is muted from about the 5th string on up the fretboard.

I've done quick and dirty measurements of clearance above the frets, and it looks like this:

Fret#/Bass side/D String/Treble side
#1/0.013mm/0.015 mm/0.013 mm
#5/0.030/0.016/0.020
#12/0.026/0.022/0.025

(Sorry ... my table formatting effort didn't work!) There are no indications of a neck joint problem: no cracks, no distortions.

So, I diagnose this as a relief problem, and it needs some truss-rod discipline. What do y'all think?

(One more fact: this has that complex Weber vaguely s-shaped bridge. I thought about just cranking the bridge up some more ... but it looks like the bridge is cranked waaaaay up: there's 0.078 mm of screw showing below the bottom of the bridge and above the top of the nut. It is every so slightly bent forward--just the slightest concave shape, barely visible, not really measurable.)

[Marty Jacobson]

Hard to tell without having it in my hands. Bring it by and I'd be happy to go over it with you.
But from looking at your numbers, I think some of them are off by an order of magnitude. For example, do you really mean your bridge is cranked up .078mm? That's the thickness of a blonde human hair. Hard to measure, let alone see, unless you're a micro-machinist.

From the numbers you posted, though, it looks like it may need a light fret dressing. Nothing major. But stuff moves around and that's one of the reasons for dressing frets.

[Ivan Kelsall]

Go with Marty's suggestion & let him have a look at it. Other than that,i'd re-set the bridge height.The string height above the 12th fret ( top of fret to bottom of string) would have been helpful info. Sudden temp./ humidity changes along with a very low action can be a problem,
Ivan

[pfox14]

Your measurements seem to be off by a factor of 10.

[belbein]

OK, don't I feel stupid. I misread the gauges. I could plead late nights, lack of sleep, stress ... but the truth is that I've done this before, so I guess it's just a case of the stupids. The measurements I gave are 1000ths of an inch.

If I had time, I'd take it by, Marty. I'd like to see you again. Unfortunately, I'm really under the gun at work. I appreciate the offer ... maybe next week or thereabouts I'll have some time freed up.

Ivan: all of the measurements are string clearances, i.e. between the bottom of the string and the top of the fret.

Can any of y'all recommend some good, easy to read feeler gauges? The ones I have, which are cheap auto supply store gauges, have the thicknesses just printed on, and they are hard to read. (poor carpenter, blaming tools, I know)

[Timbofood]

Get in touch with Peter Jenner, see if he's worked the kinks out on his new design.
Don't say I'm not supportive Peter

[Bertram Henze]

#12/0.026/0.022/0.025 ... if these are inches as you said, that means there's one of my OM A strings barely fitting under at the 12th fret. That's not low action, thats a flat tyre. But the cold weather (with the resulting lower indoor humidity) may well have caused the top to shrink a bit, which is typically countered by cranking up the bridge some more (which my solid bridge can't do, for instance, that's why I have case humidification in winter).

[Ivan Kelsall]

My apologies belbein re.your measurements. All my mandolins are set up with the exact same action at the 12th fret.The necks are all 'flat' = no 'relief',that's what Weber told me about how they were sent out from their workshop. The 'G' string height is 2mm & the 'E' string height is 1.5mm. You don't really need feeler gauges,a good quality,easy to read 6" steel rule with mm's on one side will be good enough.With sliding gauges under the strings,there's a danger that you could lift them sightly unless you're very careful indeed. Feeler gauges are fine for measuring 'solid' gaps only (IMHO),
Ivan

[pops1]

I like to measure in 32's the G i like 1.5 to 2/32 the E 1 to 1.5/32 depending on the set up of the instrument. I am referring to mandolin and a mandola may need to be slightly higher in which case use the higher of the recommended heights. Sometimes i like using mm some times fractional measurements, just what i got used to.

[tree]

The quick and dirty thought I had was perhaps it dried out a little . . . you might try humidifying it (if you haven't already) and see if that changes anything.

I discovered I had gotten behind on humidifying my instruments recently and got diligent about my Dampit use . . . in just a couple of weeks, the tops rehydrated, action very slightly raised, tone improved (I think, anyway).

I could tell because for several successive sessions, when I took the mandolins out of the case and checked the tuning before picking, they were consistently (and surprisingly) sharp.

[Marty Jacobson]

No need for anything drastic, if those are in inches. I wouldn't worry about anything yet. Jack up the bridge until it plays cleanly all over the fretboard. Then lower the bridge until it's as low as it will go without buzzing. If that is unplayable, then you can start messing with the truss rod and fret dressing. But I think all should be fine.

[Pete Jenner]

That's the thickness of a blonde human hair.

I always thought blonde was thicker than brunette. The things you learn here.

[Tom Haywood]

If it hasn't been kept humidified lately, then I would put it in a case with a humidifier for a week before making any adjustments. We just had three weeks of very low relative humidity. 20% - 25% inside my office (with plants) for several days, and well below 45% for the rest of that time.

[belbein]

Thanks, everyone. Thursday here was warmer and wet. Thursday night, it was back to normal. I kept it overnight Friday and Saturday in a case with a small case humidifier, and it's now fine. Since the cold weather now appears to be over, I'm going to leave it alone, but I am going to look for a humidifier for the room where they hang.

[Tom Haywood]

Very good. The simple solution is to put it back in the case with a humidifier after playing as long as you are running the furnace.