When not to Truss Rod

[Sevan]

Hey guys, I was wondering if I could get away with not having a truss rod on a 19 1/2" scale length mini guitar build. I built a cigar box guitar with a 19" scale length with no truss rod and no problems. Many people build the at a 25 1/2" scale length, but they also only have 3-4 strings. I'm only asking because I can a really good deal on a 19 1/2" scale neck (cheaper that materials), but it has no truss rod.

[Crusader]

I think it would be okay, it is so short

[Bizman62]

Back in the day no guitars had truss rods and they were just fine. Then again, the necks were bulkier than what now can be found in modern electric guitars.

I've got a couple of acoustics from about 1940's, the scale lengths being roughly 24 and 25". Both have a straight neck or at least straight enough for a low action without a truss rod.

A lot depends on the wood. They didn't fertilize forests when the trees for my guitars grew which made the wood tight and hard. For cheap necks they may use whatever wood they can easily get. Check the end grain for direction and tightness. If the growth rings are vertical and tight, you've got a quality neck. If the rings are horizontal and sparse, the neck is more likely to give in.

You can also reinforce a neck or even insert a truss rod. A fellow builder had an old acoustic similar to mine with a bent neck. He removed the fretboard and inserted a couple of carbon fibre rods. Many things are doable if needed! Are they cost effective is another question...

[Sevan]

Thanks for the quick replies. 

Removing the fretboard and installing carbon fiber rods wouldn't cost much of anything but time, provided you don't buy the rods from a music or luthier store. I've removed a fretboard before, but I've never routed a carved neck. That would be the tricky part.

I always thought the older guitars still used a reinforcement bar.

Edited March 20, 2023 by Sevan
Word edit

[Bizman62]

3 hours ago, Sevan said:

I've never routed a carved neck. That would be the tricky part.

Think about the neck being attached to an acoustic body while doing that. And the guy who did that is a hobbyist, first time he did anything like that.

Actually it would be very easy to secure a carved neck on a board between two rails that can be used both for aligning the router and keeping it from rocking.