Really need advice on humidifying second hand HD-28

[erkus]

Hi Guys!

I'm new to this forum. Apologise in advance if I'm missing a sticky thread for this or similar, but I'm really stressing out about my new-to-me Martin HD-28 2018.

I bought the guitar a couple of weeks ago and figured that I'd have time to sort out the RH% situation once I got guitar. It showed up online at my local store and the deal was too good to pass on. I made the proper inquiries about the condition and everything seemed fine. Images looked great. One previous owner that hadn't played the guitar at all and a really good second hand price so I went for it.

After playing the guitar for two weeks there's a noticeable belly that I didn't notice when I got the guitar. There's also a couple of tell tale bubbles in the finish on the back near the binding just where there's a brace. I'm thinking that the RH% in my apartment for the last couple of weeks might have caused significant drying. The RH% in my apt. seem to be somewhere between 35% and 40% for the most part. Not optimal I guess. I have no idea if that is enough to cause this over ~2 weeks.

I've bought an Oasis OH-5 and a hygrometer. Three issues remain:

1. I can't close the case lid (Martin thermoplastic standard case) with the humidifier mounted on the strings in the sound hole. The cap protrudes too much. I've made a MacGyver solution and tied it in place with a piece of string until I figure out what do to. I tried gluing the stabiliser bar thing on top of the cap, but the cap is too wide to fit between the D and G strings without really bending them so I removed it. I'd really love suggestions on how to solve this. The case with the guitar in it doesn't really have to be transportable since I'm stuck at home anyways. Messing around with the string every time I want to play doesn't really make the guitar accessible.

2. I've put the hygrometer by the sound hole as well. The thing is that it hasn't registered any increase in humidity at all since I put it there 24h ago. This is what is stressing me out. I put the humidifier and the hygrometer in a lunch box to see if the thing worked and the RH took off immediately so both humidifier and hygrometer probably works. But why doesn't it register? I'm scared that it's not working in place and causing more dryness and potential damage.

3. I use medium gauge strings (.013 to .056). Considering the state of things, should I perhaps detune the strings for a couple of days and leave everything in the case?

I've never had guitars nice enough to have to care about these things before so I'm a bit lost. Have I missed anything else that is important? Ive attached a link with some images to help explain my ramblings

https://imgur.com/a/2Bnwuhv


All the best
//Erik

[Dyson Guitars]

Hey Erik,
First thing, putting a straight edge over the top is not showing a belly but the arch of the top that is built into it. That is a good thing, you'll know your guitar is too dry when that arch is flattened out.
The bubbles in the finish look like either a small separation or a bad fill under the finish. I don't know how that would have to do with humidity but maybe it can. I wouldn't worry about them any way other than aesthetically but that is me.
38% isn't a bad humidity, you're about 7 away from perfect. 45 is about perfect for most folks but I'm betting you are close enough, just don't let it fall much lower.
They make a flat humidifier that just goes into the soundhole of the guitar that wouldn't interfere with your case if you want to search one out. Kyser Lifeguard I think it is called.

Relax and enjoy playing that awesome guitar!!!

[kriso77]

I recommend buying a set of D'Addario Humidipaks. They are a little pricy compared to the conventional sponge humidifiers, but it takes the guesswork out of humidifying your guitar. 35%-40% is not perfect but far from extremely low. Unless you are leaving your guitar near a heat register or baseboard, I doubt serious problems would occur that quickly.

Hydration is a somewhat slow process. It may take anywhere from days to weeks for it to regulate, but if you keep it in the case when not using it, you should see some improvements. I like the Humidipak's set it and forget it approach. They are designed to hydrate your guitar and case somewhere around 45-49%.

The bellying could also be caused by the medium strings. If there is too much tension, it could cause that to happen.

[Bob from Brooklyn]

Welcome! Nice guitar! Probably be a good idea to have a pro look at it.

[SkipII]

Others can address the remedies, but to address your humidity issues:

1. Your guitar top is not over-bellied. Some belly is normal and enhances the tone. Yours appears very normal, actually optimum.

2. Dryness would not cause bellying. Over-humidifying would.

3. The imperfections at the binding could be from over-humidifying or even under-humidifying. It is the finish coat separating from the substrates, in this case the plastic binding or the adjacent wood, as a result of some movement there. Sadly, I am seeing this more and more on newer Martins and it is more likely attributable to poor prep on the lacquer. If you got a "deal you couldn't pass up" then I would let this pass as well as the price of admission to the used guitar market.

4. Relax and enjoy it. It's an HD-28, not a Faberge egg. Wail away. Congrats.

[erkus]

Thanks for the replies! Feel a bit calmer now

The paint finish doesn't bother me at all as long as something bad isn't causing it.

However I still don't understand how the hygrometer can be stuck at ~38% with the "plus" humidifier literally right next to it for a day+. Maybe the case lining or something else in there is sucking up the moisture? It seems to seal pretty well. I'll check out the Humidpaks and the Kyser Lifeguard.

I'm thinking that in the long run, it might be easier to just get a guitar stand and a room humidifier. I have no idea on where to begin or how to set that up though. Any good sources to read up on it that you'd recommend? Am I wrong in thinking that it would be easier to get a precise RH% in the long term doing that instead of having it in the case with what really feels like afterthought solutions?

I didn't imagine this much hassle but it really doesn't matter because the guitar is so good. It's like i've been flying a Cessna all my life and someone suddenly handed me a jet fighter

[SkipII]

Originally Posted by erkus

Thanks for the replies! Feel a bit calmer now

The paint finish doesn't bother me at all as long as something bad isn't causing it.

However I still don't understand how the hygrometer can be stuck at ~38% with the "plus" humidifier literally right next to it for a day+. Maybe the case lining or something else in there is sucking up the moisture? It seems to seal pretty well. I'll check out the Humidpaks and the Kyser Lifeguard.

I'm thinking that in the long run, it might be easier to just get a guitar stand and a room humidifier. I have no idea on where to begin or how to set that up though. Any good sources to read up on it that you'd recommend? Am I wrong in thinking that it would be easier to get a precise RH% in the long term doing that instead of having it in the case with what really feels like afterthought solutions?

I didn't imagine this much hassle but it really doesn't matter because the guitar is so good. It's like i've been flying a Cessna all my life and someone suddenly handed me a jet fighter

I remember the day I traded for an HD-28 after years of much lesser instruments. It's a Rite of Passage.

You will get different views on hanging your guitar. Music shops do it as a common practice (but recognizing that their focus is to show off the guitars, not protect them for life). Th better dealers closely control humidity, but most stores do not. As a general rule, you guitar is MUCH better off in a good case. Any sporadic changes in humidity would take a while to work their way into the case. The case will provide a more more stable humdity environment, which in the short-term is as or more important that any precision around the exact RM itself (assuming you are fairly close to a normalized 45%).

[Martin_F]

Guitars are fairly robust things. Unless your humidity is extremely low, you likely aren't going to do any damage in a couple weeks. I only work to humidify my guitars to 40%, so you aren't far off of where I keep mine regularly. Anywhere between 30-70% humidity isn't likely to hurt a guitar in the short-term. 40-60% being optimal for the instrument in the long-term. I find guitars actually sound better closer to 40% humidity than they do being higher. I'm not sure where the idea came from that guitars automatically break below 40% humidity. Back in the old days, no one humidified and those guitars seemed to make it out alive. Not that you shouldn't protect your guitar and humidify it, you should. But, it's nothing to be overly paranoid about. Where you have to be more worried is when the humidity dips below 30% or like where I live to below 20% in the winter. I generally don't even start to humidify my guitars until my house consistently goes closer to 35 or 36% humidity.

You don't have to put the oasis in the sound hole if you can't do it. I just throw mine in the case beside the guitar up by the neck/body joint where there is a little space.

I wouldn't worry too much about these things. Enjoy the guitar! It's likely those finish issues were there in the first place. That is why it had a good price on it.

My opinion...
Martin