String tension

[Eddie]

I have several acoustic guitars that are very valuable to me. Do heavier gauge strings ie 12-53 and 13-56 add appreciably to the string tension and contribute to bowed necks?

[Stubee]

Not for guitars that are designed for it and in good structural condition & taken reasonable care of. My '53 LG2 wears 12s and my '52 J-45 wears 13s, full tension for decades.

All guitars necks 'lean' toward the body over the years resulting in need for some saddle lowering & maybe a neck set way down the road...or maybe not.

Using strings that are too heavy for a guitar design will first put excess tension on the guitar bridge & top & can cause problems. A bowed neck could result from higher tension than a guitar is designed for, but necks are a lot sturdier than guitar tops + have truss rods for added stability & adjustment.

A neck that takes a bad bow set under decent care is to me like one that twists = a bad neck.

[H. Mac]

Do heavier strings increase tension and the possibility of bowing? Yep.

The heavier the string gauge, the greater the tension. Every acoustic in existence is in the process of collapsing toward its middle, and the only good thing is that it's happening in slow motion.

Given enough time though, tension will eventually have an adverse affect or a combination of adverse affects on every acoustic. High action is the most common symptom of tension.

You mentioned neck bow so - - with neck bow, the neck warps or cups along its length, and tension usually causes it. The need for a neck set (or re-set) also results from tension, but is different from neck bow.

Although the two can occur together, I say they're different because they require different fixes.

Neck bow is fixed by "unbowing" the neck, with truss rod adjustments, applying weight over time, sometimes with a new fingerboard, new frets, etc. A neck reset involves the removing and reinstalling the neck at a slightly increased angle.

Both fixes result in lowered action.

If there is neck bow, or if a neck reset is needed, lowering the saddle is not a proper fix, even though it lowers the action. It's a temporary shortcut and not a good one.

Shaving the bridge is an even worse temporary shortcut, since it weakens the bridge structurally.

(And yet I have an 0-18 with a shaved bridge and lowered saddle that's been crying out for a neck set for years! Sounds and plays great just like it is!)

But you're supposed to like your guitar, so if you like heavy strings, don't use light ones. I'd try light ones before I made up my mind though.

[Stubee]

Well here's what I'm trying to convey as I was maybe too focused on the term 'neck bow':

Like others said, tension eventually does something to a flattop, it's called 'being a guitar'.

That said, I've come across about 1 'needs work' neck bow or neck twist for every 100 or so lifted top, neck 'tilted up' (needs neck reset), loose braces, lifted bridge or other tension-related issue on vintage Martins & Gibsons. This is for guitars that had at least reasonable care.

On what strings: many old small bodied guitars were damaged with strings too heavy for the build. So figure out what yer guitar will take & use those as a max. Many 00 sized guitars can take 12s, dreads usually 13s. It varies...

Will lighter strings hold off need for a neck reset etc.? Yeah maybe, but its still tension & you may not enjoy the 'benefit', if any, in your lifetime so play what it can take & enjoy it.

[Eddie]

Thank you for the replies

[H. Mac]

Originally Posted by Stubee

Well here's what I'm trying to convey as I was maybe too focused on the term 'neck bow':

Like others said, tension eventually does something to a flattop, it's called 'being a guitar'.

That said, I've come across about 1 'needs work' neck bow or neck twist for every 100 or so lifted top, neck 'tilted up' (needs neck reset), loose braces, lifted bridge or other tension-related issue on vintage Martins & Gibsons. This is for guitars that had at least reasonable care.

On what strings: many old small bodied guitars were damaged with strings too heavy for the build. So figure out what yer guitar will take & use those as a max. Many 00 sized guitars can take 12s, dreads usually 13s. It varies...

Will lighter strings hold off need for a neck reset etc.? Yeah maybe, but its still tension & you may not enjoy the 'benefit', if any, in your lifetime so play what it can take & enjoy it.

Yep, I agree, Stubee. Neck bow (and twist) is far more rare than the need for a neck reset and the other repairs that Stubee mentions. In fact, I was a bit curious that the OP mentioned it.

And I'll confess - my 0-18 with it's lowered saddle and shaved bridge could be the "poster guitar" for a neck reset advertisement. It begs for one!

Yet, everyone who plays it is flat out shocked by this little guitar. Typically, people play it for about 15 seconds, stop, turn it top up and look at in disbelief, shake their heads and smile, compliment it, then play it some more, compliment it some more, etc.

I have had more offers for this 0-18 than for all of my other guitars put together! If I can dodge getting the neck rest for a few more years, great!

[Stubee]

And I'll confess - my 0-18 with it's lowered saddle and shaved bridge could be the "poster guitar" for a neck reset advertisement. It begs for one!

Yeah, I've had my '52 J-45 for probably 10-12 years and it could use a reset just cuz the saddle is low...but it is a beater, it sounds great, and it hasn't moved a fraction since I bought it. Did have a really really beat '51 J-50 that finally got to the "must reset" time after about ten years of heavy playing by me--was close when I bought it for $425!--but I sold it and got the J-45 to replace it. I'll tell ya, the J-45 is great but I still miss that whipped out J-50.

Guitars are odd things and it sure is tough to predict what one will do vs. another.