Martin D18 GE Custom Shop 12 fret - set up questions...

[coolhand78]

Originally Posted by charles Tauber

It looks like you have 5/32” at the 12th. To get it to 3/32” you’ll need to remove 4/32 (1/8) at the saddle. Looks like your current saddle projection is about 5/32. If you remove 4/32, you’ll have 1/32” of saddle projection, which is not enough for an appropriate break angle. Doing so will also reduce the vertical height of the strings from the top at the bridge. Martin’s target design height is about 1/2”. Reducing that significantly might change the volume or tone of The instrument.

Unless the bridge is thick and can be shaved, you might be looking at a neck reset. Again, you should have a skilled professional assess it first hand.

There are other things that can be done, but are not advised on a new purchase unless the purchase price was commensurate.

This is what I fear!

[coolhand78]

Originally Posted by Zissou Intern

Also wondering... is there a significant belly behind the bridge?

There doesn't appear to be - I'll inspect closer tonight and report back.

[JayBee1404]

Originally Posted by Zissou Intern

Also wondering... is there a significant belly behind the bridge?

Originally Posted by coolhand78

There doesn't appear to be - I'll inspect closer tonight and report back.

The 'significant belly' Zissou is referring to can be checked by laying a straight-edge across the bottom bout directly behind the bridge - a total of 1/2" or less (adding the gap on both sides together) is generally accepted as the 'normal' range on a Martin Dreadnought.

Apologies if you already knew this.

The usual disclaimers apply......IMHO, YMMV etc.

[coolhand78]

So placing a ruler across the belly of the guitar and measuring the gap to between the top and the ruler i get 3/32nds...

[JayBee1404]

Originally Posted by coolhand78

So placing a ruler across the belly of the guitar and measuring the gap to between the top and the ruler i get 3/32nds...

Is that 3/32" at the guitar's edge on both sides, or both sides added together = 3/32"?

Either way, that's not a lot so I'd guess that the problem isn't caused by 'excessive belly'.

I'll repeat my earlier advice, also Charles's - get thee hence to a good tech/luthier and let him/her do a proper assessment of the guitar. A GE is a fine instrument, too good to go on guesswork.

The usual disclaimers apply......IMHO, YMMV etc.

[coolhand78]

So I took the guitar to a qualified luthier today, and it appears that I was off on my measurement of the neck relief; the tech measured it more accurately at 0.025" and mentioned that it should be more like 0.010"...

He also commented that the bellying was more significant than I'd first thought as was the height of the strings at the first fret.

So the upshot is that over the next few days he's slowly going to tighten the truss rod and bring the neck back to a more acceptable level and then re-assess from there.

I'm very keen to hear peoples thoughts on this.

Thanks for your help.

[JayBee1404]

0.025" is a lot of relief! Bringing it back to 0.006 - 0.010" might correct the high action at the first fret, and it will certainly reduce the 12th fret action, although probably not by the 0.0125" needed. If the bellying can be reduced, you'd gain a little there too.

Did he give you a number for the bellying? That could be the result of over-humidification, or maybe a loose brace, both fixable.

Anyway, it was a good move taking the guitar to the luthier - keep us posted how things move along please?

The usual disclaimers apply......IMHO, YMMV etc.

[coolhand78]

Originally Posted by JayBee1404

0.025" is a lot of relief! Bringing it back to 0.006 - 0.010" might correct the high action at the first fret, and it will certainly reduce the 12th fret action, although probably not by the 0.0125" needed. If the bellying can be reduced, you'd gain a little there too.

Did he give you a number for the bellying? That could be the result of over-humidification, or maybe a loose brace, both fixable.

Anyway, it was a good move taking the guitar to the luthier - keep us posted how things move along please?

The usual disclaimers apply......IMHO, YMMV etc.

He checked all the bracing and said it was fine, I'm in Australia and bought the guitar from a guy in Sydney, so humidification may very well have been an issue...

[zhunter]

In general, no need to wait a few days to dial down that relief unless there is a serious humidification issue he wants to fix. As noted 0.025 is a lot but, unless the truss rod is not functioning properly, tighten it up and get the relief right. Wet season go as close to flat as you dare. Dry season ~0.007. A typical GE neck is pretty robust and once set probably won't move around to much. But wood will be wood and unexpected behaviors can occur. Be sure you remember the belly numbers from an earlier post. 1/2" total would not be significant on a Martin.

Between setting the relief and getting the nut slots right you may be surprised at the difference in action. Have to wait and see.

hunter

[charles Tauber]

Originally Posted by zhunter

Between setting the relief and getting the nut slots right you may be surprised at the difference in action.

Likely, that's all it needed. .025" of neck relief is likely the main issue, easily fixed with a working adjustable truss rod.

[JerryM]

A Good Qualified Luthier is the only way to go before messing with it!! I have had 4 Martins now in the past 10 years with neck angle, saddle height issues.Underset necks being the biggest problem, I won't buy a Martin anymore before actually playing it and close examination. I actually take my measuring tool with me when looking. A Collings, or Bourgeois, no worries but any of these set in necks are expensive to reset and in my experience soon eat up any left over funds in a good deal....

[coolhand78]

So the news wasn't good. It appears that there's a kink in the neck. ie. the neck angles upwards from the neck join.

The tech was able to straighten the fretboard between the 1st and 10th frets but when you lay a straight edge along the frets there's a distinct and visible gap. he can also slide a .002" feeler guage between the fretboard and the soundboard. The kink is actually quite visible by eyesight alone. If you use the string as a straight line you can see the gap gets larger as you reach the 12th fret then it starts to get smaller again as you reach the end of the fretboard.

So it looks like i'll be sending this one back...

[pandaroo]

Originally Posted by coolhand78

So the news wasn't good. It appears that there's a kink in the neck. ie. the neck angles upwards from the neck join.

The tech was able to straighten the fretboard between the 1st and 10th frets but when you lay a straight edge along the frets there's a distinct and visible gap. he can also slide a .002" feeler guage between the fretboard and the soundboard. The kink is actually quite visible by eyesight alone. If you use the string as a straight line you can see the gap gets larger as you reach the 12th fret then it starts to get smaller again as you reach the end of the fretboard.

So it looks like i'll be sending this one back...

I hope the seller is a reasonable person and accepts it back.