Purposely Over-humidify to fix belly bulge?

[mattx]

I have an Alvarez Masterworks dread that is only a couple months old. It has been kept in the case at all times and I'm using the D'Addario 2-way humidipaks in it.

Despite that, somehow it has developed a pretty bad belly bulge and very high action presumably from being overhumidified. It presents mostly a big rise behind the bridge with no visible dipping in front of the bridge. There are even some fine finish cracks at the corners of the bridge.

The guitar has forward shifted bracing and is all solid. The bridge is still glued down well and the braces look good.

I tried drying the guitar out with no tension on the strings for several weeks. This only helped a small amount and most of the belly came right back when the strings were at full tension.

I've decided to try again by slackening the strings and purposely overhumidifying the guitar in the case before trying to dry it out again...

Has anyone tried this? Am I going to regret it?

[charles Tauber]

Most factory guitars are made in an environment of between 40 and 50 % relative humidity. Use a hygrometer to measure the relative humidity of the environment in which you store your guitar. If you can maintain it at the 40 to 50% range, you will not see significant changes in the geometry of the instrument due to humidity and can rule that out as a cause of geometric changes.

If your guitar, when maintained in the appropriate range, has geometric changes, such as the top bellying, it won't be due to humidity issues. Some rising of the area between the bridge and butt is common in many guitars. Many guitars are made with an arched top. One should not confuse the arch with "bellying".

The absence of string tension is irrelevant to the guitar's ability to absorb or desorb moisture. By removing string tension, you've simply determined that under string tension the guitar has more bellying than you think it should. That could be caused by loose braces, heavy strings or inadequate bracing.

Beyond maintaining the humidity level, if the action is too high and you believe there is excessive bellying, your best best is to have it looked at by a qualified repair person who can assess the situation and suggest remedies.

[mattx]

Humidity on the main floors of my house is perfect. The basement runs a bit higher (low 50s). I had the guitar in the case in the basement with the 2 way packs in it when the belly happened. I guess the 2 way packs weren't enough.

The top was almost entirely flat when I got the guitar. I can't see any problems with the braces. I'm bummed about it.

[edcmat-l1]

If it's only a couple months old wouldn't it be under warranty?

[mattx]

Warranty is lifetime but reading up on the site it seems like they would deem this "environmental damage" and not cover it. I can ask the dealer. It also has quite a bit of saddle height so I can probably just do a setup on it to fix the action. Just seems like the top isn't stable and this is likely to get worse.

[charles Tauber]

Originally Posted by mattx

Humidity on the main floors of my house is perfect...

The top was almost entirely flat when I got the guitar... I'm bummed about it.

Leave it strung at full tension. Store in on one of the main floors where the relative humidity is "perfect". Leave it there for a week or two, playing it as you wish. If it a humidity-related issue, then it should return to being the way you purchased it. Having the guitar in low '50's relative humidity and "normal" household temperatures will not cause "environmental damage". Wood absorbs and desorbs moisture in response to its environment. As it does so, it changes size and shape. That's what wood does. That's why one attempts to control the relative humidity of fine articles made of wood.

Photographs and measurements would help to interpret the magnitude of the problem.

[mattx]

Thanks for the suggestions. I'll take some measurements and photos and post back.

[phavriluk]

I don't know where OP lives, but in New England, humidification comes when the heat goes on, the other seven months of the year, no need to humidify. Certainly not in midsummer.

[JayBee1404]

I find the concept of ‘deliberately over-humidifying’ a guitar that already seems likely to be over-humidified very puzzling. All that would do is exacerbate the problem, surely, like trying to put a fire out by pouring gasoline on it?

If it were my guitar, I would buy an in-case-hygrometer, store the guitar in its case for a period of several weeks, and check frequently that the in-case RH is within range. If it’s high (>55%), I would put some of those silica-gel desiccant packs in the case to reduce the RH.

But add more humidity to an already over-humidified guitar? Nope, makes no sense AFAIC!

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

[JayBee1404]

Originally Posted by phavriluk

I don't know where OP lives, but in New England, humidification comes when the heat goes on, the other seven months of the year, no need to humidify. Certainly not in midsummer.

Same here where I live, in ‘Old’ England!

When the heating comes on - October usually - and the RH in the house drops below 40%, the guitars go in their cases with the humidifiers. When the heating goes off - April-ish - and RH gets into the low 40s and above, the guitars come out of their cases and live in the ambient RH of the house for the whole of the summer.

That’s been my regime since I had a dried-out guitar over the winter of 2004/5, and my guitars have been in good health for fifteen years.

[DavidE]

Originally Posted by mattx

Humidity on the main floors of my house is perfect. The basement runs a bit higher (low 50s). I had the guitar in the case in the basement with the 2 way packs in it when the belly happened. I guess the 2 way packs weren't enough.

The top was almost entirely flat when I got the guitar. I can't see any problems with the braces. I'm bummed about it.

Those 2 way packs actually start at high 50's in relative humidity. So even if your basement was low 50's, your guitar was seeing high 50s. If the packs are new, they're wet and can't absorb more moisture.

[RonMay]

Originally Posted by mattx

I have an Alvarez Masterworks dread that is only a couple months old. It has been kept in the case at all times and I'm using the D'Addario 2-way humidipaks in it.

Despite that, somehow it has developed a pretty bad belly bulge and very high action presumably from being overhumidified. It presents mostly a big rise behind the bridge with no visible dipping in front of the bridge. There are even some fine finish cracks at the corners of the bridge.

The guitar has forward shifted bracing and is all solid. The bridge is still glued down well and the braces look good.

I tried drying the guitar out with no tension on the strings for several weeks. This only helped a small amount and most of the belly came right back when the strings were at full tension.

I've decided to try again by slackening the strings and purposely overhumidifying the guitar in the case before trying to dry it out again...

Has anyone tried this? Am I going to regret it?

I know I'm going to receive a lot of flack and negative comments on this. But it's worth saying.

FORGET ABOUT THE HUMIDITY.


Jerry Rosa of Rosa String Works says it best. He's been a luthier for over 30 yrs and I believe what he says is true. Remember there are always exceptions to every rule.

Check it out and decide for yourself.

https://www.youtube.com/watch?v=tHOu8sVf9EA

Ron

[charles Tauber]

Originally Posted by RonMay

I know I'm going to receive a lot of flack and negative comments on this. But it's worth saying.

FORGET ABOUT THE HUMIDITY.


Jerry Rosa of Rosa String Works says it best. He's been a luthier for over 30 yrs and I believe what he says is true. Remember there are always exceptions to every rule.

Check it out and decide for yourself.

https://www.youtube.com/watch?v=tHOu8sVf9EA

Ron

I watched the video in its entirety and listened to what he said. There is a middle ground between the obsession about humidity and complete neglect.

There are factual inaccuracies in what he says. The bottom line is that guitars do crack and the cause of that is usually low environmental humidity. To suggest otherwise is to court negligence.