I am a guitar player who has an electric, an acoustic, and an acoustic bass. I’m contemplating getting a mandolin just to have something to noodle on if I’m travelling or whatever.
If I got one I am thinking of reversing the string order so that the tuning would be in the same order as the first four guitar strings, or as all of my acoustic bass strings.
Are there any mandolin players out there who have thoughts on that? Is there any specific reason why I shouldn’t string it that way?
Take this with a grain of salt: I’ve always heard that stringed instruments are built with additional bracing on the side with the higher tuned strings and reversing the order puts undue stress on the whole instrument resulting in, at best, chronic tuning problems and, at worst, damage to the instrument.
That sounds like it makes a lot of sense, salt notwithstanding 
. I’m curious to hear other opinions.
Further, when you see, say, Paul McCartney playing lefty, his guitar has been built in reverse. I’d bet this is a recent thing (like, the last forty years) because it’s expensive for regular Joes as they make much fewer lefties. Safe to say his Hofner bass wasn’t a lefty?
It’s always bothered me that there are no “lefty” pianos.
BTW: there are travel guitars (pretty sure Martin makes one) that are much thinner and bowl-less and lighter for taking into the woods and annoying wildlife. 
I play all the instruments you mention.
Standard mandolin tuning is in 5ths (G-D-A-E) whereas standard guitar tuning is in fourths. The string tensions might be an issue if you want to tune a mandolin in fourths.
You wouldn’t be able to buy a standard set of mandolin strings, you’d have to figure what gauges to buy and get them by the each.
If your goal is to play guitar chords and shapes in a higher register, you might be better off with a “manditar” or some similar instrument. Or a tenor guitar, which can be tuned either in fourths or fifths.
I have a lot of guitars and one really cheap mandolin. I think the nut is going to be an issue. The grooves for the strings are cut to fit the string sizes (anything else would probably result in tuning issues). It’s not cut symmetrically from headstock to fretboard, so you can’t just pop it out, turn it around and glue it back in.
The bridge is also probably going to be weird. Mandolins don’t normally have individually adjustable saddles. They’re cut in a staggered way that also can’t be flipped around and get you the opposite stagger. Most of them do have floating bridges that can be moved around. You can probably get at least two strings to intonate well, but the other two will probably be wonky due to the stagger being off.
The rest of it is pretty symmetrical. The tuning pegs and tailpiece on mine won’t care what gauge string is running through them, at least. Have you thought about getting a left handed mandolin and flipping it over to play it righty?
That’s why you get paid the big bux. 
@scabpicker all the things that you mentioned were things about which I had no idea. And the left-handed mandolin idea is brilliant; I never even considered that.
And, if I get a mandolin, it too will be one really cheap mandolin.
It is kinda sinister, if you think about it.
It’s still the right thing to do, I think.
Ha! Touché
Glad to be of help! One thing I will say about this plan: The flipped over chord shapes work pretty well. The scale shapes don’t, of course.
You two are just precious. 
Your E string will always be the lightest one, no matter where it’s positioned.
You seem to think that they’re planning on tuning the mandolin like the four lower pitched strings on a guitar, in fourths. They don’t seem to be. Their original plan was to leave the strings tuned to their current pitches, but change the order from top to bottom. That’s impractical on most mandolins. So instead of re-stringing a righty mandolin, they seem to be planning on playing a lefty mandolin right handed, accomplishing the same thing.
The only real benefit is that the chord shapes from a guitar would work just fine, even if they’re not always the same inversions that a mandolin player would choose. Scale patterns don’t work, but scales on a mandolin are fairly easy.
I guess, bearing in mind that there are only four pairs of strings (or four notes at the nut), I guess I’m looking at something along the lines of a “Shredneck” that actually plays.
So, instead of G-D-A-E, I would have an instrument that plays E-A-D-G. Though not the six strings of a guitar, they would be in the same sequence of the first four notes of a guitar, or all notes of my acoustic bass.
Well, but the flipped over order of strings would be in inverted in order, but not pitches. Still tuned in fifths from the lowest pitched string to the highest pitched string, just with an inverted layout on the fretboard. As I said earlier, the chord forms from the lower four strings of a guitar would generally work in this setup. With scales, you’d be working in normal mandolin patterns, reversed from top to bottom. A little weird, and you’d probably have a bit of a confusing time talking to other mandolin players on technique. But that’s kind of to be expected since you’re changing how you play the instrument.
If that wasn’t your plan, you probably would need to go with custom gauges of strings as @Jaycat.again mentioned, at least for the higher pitched strings. In the most basic case of just tuning them from GDAE to EADG, you wouldn’t want to invert how the mandolin is strung, but largely just lower the pitches of the strings. The low E is available just a minor third down from G, so probably doable with the current gauge. But that high pitched G string would be a nine semitones down from its original E. I’d imagine at least that would have to be a thicker gauge than the high E on a normal mandolin, otherwise it would be very floppy. The string tuned to D in this new tuning would probably have to be thicker, too.
Really, mentally flipping the fingering around from the guitar form’s chord shapes to work on a normally strung mandolin to experiment with this idea wasn’t hard for me (other than my hot dog fingers, which are a factor to contend with on anything but bass or steel guitar), but it is kind of odd. You could do that as a placeholder until you figured out the mandolin’s native chord and scale forms.
We’re here to help!
Can you imagine the re-sale value of a left-handed Piano? Sadly “real” Pianos are a bit of a liability, or can be, these days.
Well, this thread sent me down a few rabbit holes… I won’t mention some (I lusted after a few backpacker guitars and other “tiny portable guitars”), but I appreciated GoldTone’s alternative-mandolin-tunings-made-simple page.
What I really wish I could do is tune my mandolin DGBE so that I could chord like the highest four strings of my guitar*. Easy for the top two strings, but that’s be quite a change for the lower two (or four, yeah, I know a mandolin is really tuned GG-DD-AA-EE).
*I have guitar chords and scales stuck in my head, and don’t play mandolin enough that I can mentally switch back and forth (same problem with French and Spanish, they both live in the same “Romance Language” spot in my brain).
You know it. People are actually giving away Steinways nowadays; my wife is on constant scan mode for one, God help me. Pray for burpo.