Truss Rod and basic guitar adjustment: Acoustics

Kettleson

Hi all:

I've purchased a few mid range acoustics and a few questions if possible.

1)
Truss Rod: Does the action of the truss rod to adjust the relief/action work in reverse on some different makes?

ie: I'm following the quarter wind(s) "clockwise" rule, but on a 70's Japanese guitar this procedure made the action way much higher. Anti-clockwise worked perfect.

2) I'm also attempting to adjust a 1969 Yamaha Fg140. The action at the 12th is a bit high, (rough assessment I can put 2 x 5 cent pieces under the 12th fret).

I adjusted the truss rod slightly clockwise by about 1/8 turn, but it just wont budge any further and I don't want to force it.

Is the action as the 12th as good as it can be? Can a truss rod be lubricated in any way? Or should I leave well enough alone? It sounds great open playing, but a wee bit high action up the neck.

3) Different guitar again. 6 string K Yairi 1974. Lovely thing. But i've just noticed that one of the internal supporting struts on the back of the guitar must be a bit unglued. (There is a bit of a knock when I tap the back).

Does this need attention from a Luthier, or should I stick with it for now?


4) Also, I'm getting into blues'ey 6 string acoustic plucking, but the medium Martins I'm using at the moment are too heavy for some of the subtle string bending. Should I just change to lights? or is there another brand/guage that it might be worth trying for this style?

PS: Any recommendation of guitar for that ^^^^ style of playing also welcome.

Cheers...

kevin65

You need to be very careful with truss rod adjustment, tighten too much and you can snap off the nut at the end. The general rule is that rotating clockwise tightens the nut onto the end of the truss rod which puts more compression on the neck and reduces the bow, i.e. pulls it straighter. Rotating anti-clockwise loosens the nut and increases the bow in the neck.

However, you should check for your own guitars before making any adjustments. Sometimes the truss rod nuts can be a bit seized, I have used a small plastic pipette to put a couple of drops of WD40 onto the end of the truss rod so it work its way down into the threads. However, if its very stiff don't force it or it could snap off.

Adjustments should be made in 1/8 turns and leave to see what effect it has before proceeding. Unless the guitars really need adjustment, maybe better to leave well enough alone.

It you're not sure, better to bring to a good luthier.

Kettleson

Thanks Kevin, very good advice.

martinedwards

truss rod adjustments are best done by folks who understand the whole thing

when building instruments I always used double action rods that worked BOTH ways, which threw the usual rules but allowed more adjustment.

I know some folks adjust their truss rods every time it rains as the humidity change effects everything so much......

I have guitars that I haven't touched the truss rods on in 30 years......

the BRIDGE is where action changes take place.

as for the brace?

cut a lolly stick to 1mm longer than a snug fit vertically between the loose brace and the top (including another bit of lolly stick inside the top, parallel to the top to spread the pressure)

wick a little regular wood glue... just bog standard PVA.... under the loose brace, then force the lolly stick in to hold it.

a wee tip.... PVA doesn't stick to polythene, so a bit of poly bag between the lolly stick and the strut will save..... problems...... after the glue has dried (allow 24 hrs to be safe)

biketard

Not that I'm suggesting you do this yourself, but sometimes when a truss rod just won't go any further it's because the wood under the nut has become compressed. Sometimes the right-sized washer under the truss rod nut can save the day.

Also while the nut's off, a small dab of vaseline on the threads works as a great lubricant. I wouldn't recommend dripping oil in there as it gets absorbed into the wood and does it no favours.

Nice lollypop fix, martinedwards!

Kettleson

Thanks folks. Very interesting and much appreciated.

Kettleson

For anyone looking in on the thread, here's a short video on neck construction and function of truss rod.

https://www.youtube.com/watch?v=loV2_sDuEo8

https://www.youtube.com/watch?v=z-8xn3BOew4

kevin65

biketard wrote: »

Not that I'm suggesting you do this yourself, but sometimes when a truss rod just won't go any further it's because the wood under the nut has become compressed. Sometimes the right-sized washer under the truss rod nut can save the day.

Also while the nut's off, a small dab of vaseline on the threads works as a great lubricant. I wouldn't recommend dripping oil in there as it gets absorbed into the wood and does it no favours.

Nice lollypop fix, martinedwards!

Agree with the dripping oil, that's why I used just a drop in a pipette onto the top of the nut. Using oil to lubricate tuning machines can also cause damage to surrounding wood if there is excess.