HELP! Troubleshooting my E10D-TC.

[jphenderson91]

The Problem!

Today I took my E10D-TC out of the case to humidify it after not playing it for a couple weeks when I noticed that the action was considerably higher than normal. The guitar had sat in it's case with a soundhole humidifier in it for about two weeks. The room stays at 65-75 degrees all year long and there is no natural sunlight in the room. So after taking the guitar out of the case I noticed a little rust on the coated G string where the soundhole humidifier sat. The strings were about 6 months old but maybe I over humidified the guitar a little bit. Humidity is about 35-40% in the room but it has rained a lot this last week. The humidity generally stays in a relatively safe range for guitars. All other instruments in the room have no issues.

Anyway, I have had this guitar for 6 years now and it has been very stable since I first got it. In fact, the neck seemed to be a little overset from the factory so I have had to use medium Martin (190lbs) tension strings and a very high saddle to keep the action from being too low. The guitar has never had high action and I have never had to tighten the truss rod because the neck has been straight since I got it.

But today I noticed that the action was a good 1.5mm higher than normal at the last fret and at the saddle.
What concerned me the most is that the guitar looked like it had a lot more belly bulge than my other Eastmans and a quite a bit more than my Martin's (which are almost flat)

Troubleshooting:

First, I noticed that there was a lot of relief in the neck so I decided to tighten the truss rod to straighten out the neck. After about a full turn of the truss rod (360 degrees to the right clockwise) the neck became straight, which brought the action down about .5mm (now it was only about 1mm higher overall than my D28 Authentic that is set up perfectly.

Secondly, I decided to do a string change and lower the overall tension on the bridge by about 15lbs (now 175lbs of tension instead of 190). This seemed to bring the action back down to about normal, but to my eye it still looks like there is more belly bulge than my other Eastmans and Martins. There seems to be a slight raised spot just behind the bridge about an inch from the low E and A strings.

What Now?

My next course of action is going to let the guitar dry out just a bit as I think I may have slightly over humidified it.

If the belly bulge doesn't go down in a week or two I am going to take it to my Eastman dealer and see what their tech thinks.

Anyway, what would you do if you were in my shoes? Do any of your Eastmans have belly bulge?

Also, I don't think the guitar is dried out because there are no fret sprout or cracks. The signs I see may point to high tension on the neck and a little too much humidity.

What do you think?

I may be able to post pic of the bulge soon.

[Victor Vector]

Yea sounds like the 13's with a steep break angle from a high saddle combined with the humidity finally got to it. Let it dry out, switch to 12's and lower the saddle height if needed and see what happens. Theres nothing much more a tech can do if it doesnt go away some other than installing a bridge doctor if its gets too bad.

[DonO]

JPH,
humidity, string tension, and light bracing all contribute to belly bulging. If you lay a straight edge across the top, right behind the bridge and there is a gap more than 1/4″ on either side, you might have a structural problem due to over humidification. I agree with Victor, take the 13 strings off, let it dry some and see what it looks like. Good luck!

Don

[Guzzi Fan]

I don't think you have to worry, JP.

I had bought an AC122-2CE (all solid sapele) that had been sitting on the shelf for a year or two.  When the guitar was shipped to me, there was a lot of fret buzz.  When I set relief high enough to eliminate the fret buzz, the action was much too high.  Based on humidity readings in the sound hole while in a closed case, the guitar was very dry.  I put several damp sponges in aerated zip lock bags, and cautiously put them in the guitar and case to humidify.

I went a little bit overboard and the belly did start to bulge. It took a few days of exposure to the winter low humidity level to bring the moisture level down, but it did come down, and so did the belly bulge.  I also left the guitar case open, as it was at an unacceptably high humidity level too. Since then, with regular humidipak use, I never had any problems again.  I have read before that humidipaks will not be enough on their own if a guitar is too wet or too dry, but they will mostly hold it stable once a guitar has a reasonable level of humidity.  

Do you have a hygrometer to measure the sound hole and case humidity?  Maybe a few days, or weeks at the ambient humidity will be enough to bring the top down again.  I would definitely open the case to the lower ambient humidy as well.

Good luck!

Rod

[jphenderson91]

[sundance]

Many guitars have been ruined with case humidifiers. The only reason that a guitar would need to be humidified is because someone built it when the wood wasn't dry. Which happens more often than you think. If you're not experiencing issues from drying, then never humidify your instruments.

[cjhorne]

Many guitars have been ruined with case humidifiers. The only reason that a guitar would need to be humidified is because someone built it when the wood wasn't dry. Which happens more often than you think. If you're not experiencing issues from drying, then never humidify your instruments.

Your advice of not using a humidifier in location with a cold winter (i.e. low indoor humidity when the heat  comes on) goes against everything I have read, and I have read a lot on the subject.  Do you have any supporting references on your advice?

That said, I have a PCH1-D - layered sides and back with a solid torrified top that has been setting out of the case all winter with seemingly no adverse effects and no noticeable change in action.  That's a lot different than a sold wood guitar though.

[Victor Vector]

https://www.stewmac.com/luthier-tools-an...20Products

[jphenderson91]

I can't comment on the humidity other than I have heard my luthier say that 30% is actually okay for a guitar (little dry but not bad) whereas 15 or 20 can start being dangerously close to cracking.

Also, I noticed today that my E1SS has some belly at the bridge as well. The saddle is somewhat tall and the action is still good on the E1SS (the action doesn't seem to have move since I got it a few months ago) which makes me wonder if a little belly is a little common with Eastmans and if it affects the playability of the guitar all that much. .

I lowered the string tension and saddle a little on the E10D-TC and it is playing much better. I have had the guitar out of the case for 24 hours now and the belly has went away some. If the action gets any lower I will have to to shim the saddle and raise it again. All of this to say the belly bulge (though it's there) doesn't seem to affect the playability right now on either guitar. Both guitars still have fairly tall saddles, low action and light strings.

I think I am going to still wait another couple weeks and monitor the guitar (and let it dry out) and then send it to my Eastman dealer to have their tech check the belly out to make sure it's not a loose brace or something else.

[sleigh]

Sundance: "Never humidify your instruments" is counter to every piece of advice I've heard on the care of acoustic guitars (as cjhrone also noted). Having owned several acoustics over the years, I've witnessed them reacting to changing humidity levels, both high and low (though yes, you can over-humidify them and cause problems.) I'd be curious as to where you heard this and who said it, and whether there's corroborating evidence.

I had an Ovation acoustic that was super-sensitive to change in humidity. When humidity was low, the strings would buzz against the frets or (well up the neck) not play at all. When humidity was high, the strings would sit well off the neck and be hard to play.