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  #31  
Old 04-03-2020, 05:20 AM
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JayBee1404 JayBee1404 is offline
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Originally Posted by Silly Moustache View Post
A point about the soap dishes - I got those funny water-bead things (still can't fathom their real purpose) and put them in small soap-dishes and taped them inside my cases.

They leaked sticky goo into the cases and onto one or two of my guitars.

I am going to try his again but with spnge between the beads and lids.
Hmmmmm....I currently have Oasis soundhole humidifiers in the Martins’ cases, a Music Nomad soundhole humidifier in the Brook’s case, and D’Addario ‘Humidipaks’ in the Lowden’s case.

I’ve never had any kind of problem with any of those humidification methods over the years I’ve used them - no leaks, RH maintained in-range throughout the winter. I’m thinking I’ll stick with what I know.

The usual disclaimers apply......IMHO, YMMV etc.
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Last edited by JayBee1404; 04-03-2020 at 06:40 AM.
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  #32  
Old 04-03-2020, 06:03 AM
Robin, Wales Robin, Wales is offline
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Hi me again!

Most of my guitars are Collings built in the 21st C. they are fine guitars but VERY sensitive to changes - and strangely, more sensitive to temperature, than RH.

My older guitars are far more stable. Are they more solidly built? Maybe, but just as resonant.

!
I do wonder about wood sourcing and age/stability. Collins make about 1500 guitars a year - that's a lot of high quality timber to source with an assumed provenance, particularly if they are not felling it themselves. Mind you its nothing compared to Martin at 85,000 per year - where is all that mahogany and rosewood coming from? I'd be surprised if Martin is buying and laying down wood now for builds programmed in 2030, more likely it is being 'cooked' to dry it. Does this have an effect on its hygroscopic tendencies? I have no idea!

I expect, however, that your older guitars were initially made from more seasoned stock - simply due to its availability.

I could be well off the mark here though !!!!!
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  #33  
Old 04-03-2020, 09:47 AM
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KevinH KevinH is offline
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Originally Posted by Robin, Wales View Post
I have a LOT of questions around this topic. Like, what is the correlation between air humidity and the hygroscopic tendency of various woods - and how does that tendency change with wood seasoning.
I find this all very interesting as well. If you haven't seen it already, you might take a look at the Wood Handbook, a free download and an interesting read while shuttered up inside. Left on its own, wood will absorb or release water to move toward its equilibrium moisture content. The EMC is quite insensitive to temperature, but depends on the RH (see Figure 4-1 in the handbook). Your question about how the tendency (I assume you mean rate of change?) depends on seasoning of the wood is a good one.

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Originally Posted by Robin, Wales View Post
...I'm at 11 deg C and 66% inside today and 10 deg and 68% outside. My guitar sounds fine. Is this related to the moisture content of the guitar woods or the way sound travels through moister air? Despite my guitar having lived above 60% for the winter I still don't get a reading above 2 or 3% water content from its woods. So is it a linear correlation and do different woods react differently?
Are you sure your moisture probe is working correctly? According to Table 4-2 in the handbook, the EMC is 11.2% for conditions of 10C and 60% RH. Out of curiosity I went outside this morning and stuck a probe into some exposed roof framing on my house - basically under the eave of the roof, where the wood (fir and cedar) are exposed to the air, but not directly to any liquid water. The RH here in the Seattle area has averaged around 60% (with 20% swings) over the past month. Temp is 4C. I measured moisture content values between 10% and 13%, consistent with the handbook value. If you have a piece of wood that's been sitting outside out of the rain, it would be interesting to try your probe on that, as a check.

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Originally Posted by Robin, Wales View Post
...I'm at 11 deg C and 66% inside today and 10 deg and 68% outside. My guitar sounds fine...
And that's really the important point. Ultimately what matters is what you see and hear happening with your guitar. I hadn't given much concern to humidity in the past. But now that I have a small herd of nicer guitars I'm watching the humidity and how the herd behaves.
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  #34  
Old 04-03-2020, 11:39 AM
Arch Stanton Arch Stanton is offline
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I am always right around 55% which i guess is optimal, but we do get dry winter days here in new england. I made a home-made humidifier out of a Harry's shave kit, the little plactic cartridge that the blades come in, it really works great. Of course you have to cut a block square-shaped sponge to put inside and i use a strip of fishing string to lower it down in the sound-hole. I admit its a bit of a pain to lower and hoist it up, but if does provide optimal humidification and lasts a long time, several weeks. I was sick of changing those little sound hole ones, always drying up too fast because the sponge is so small.
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  #35  
Old 04-04-2020, 06:50 AM
Robin, Wales Robin, Wales is offline
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Originally Posted by KevinH View Post
I find this all very interesting as well. If you haven't seen it already, you might take a look at the Wood Handbook, a free download and an interesting read while shuttered up inside. Left on its own, wood will absorb or release water to move toward its equilibrium moisture content. The EMC is quite insensitive to temperature, but depends on the RH (see Figure 4-1 in the handbook). Your question about how the tendency (I assume you mean rate of change?) depends on seasoning of the wood is a good one.



Are you sure your moisture probe is working correctly? According to Table 4-2 in the handbook, the EMC is 11.2% for conditions of 10C and 60% RH. Out of curiosity I went outside this morning and stuck a probe into some exposed roof framing on my house - basically under the eave of the roof, where the wood (fir and cedar) are exposed to the air, but not directly to any liquid water. The RH here in the Seattle area has averaged around 60% (with 20% swings) over the past month. Temp is 4C. I measured moisture content values between 10% and 13%, consistent with the handbook value. If you have a piece of wood that's been sitting outside out of the rain, it would be interesting to try your probe on that, as a check.



And that's really the important point. Ultimately what matters is what you see and hear happening with your guitar. I hadn't given much concern to humidity in the past. But now that I have a small herd of nicer guitars I'm watching the humidity and how the herd behaves.
Thanks for the info. My gauge could not be accurate at a 2% reading, the floor of accuracy for electric gauges is 6%. I'll try to get a better reading when the strings are off and I can get the probes deep into the neck or tail block rather than the surface of a brace. As you say, I should be reading 10% or so.

That Wood Handbook is a complex read! I'm not sure I understand all the scientific equations but, ostensibly, once wood is at its environmental equilibrium it should only take up and release water content slowly (ie seasonally) as the RH and temp change. The sudden fall of RH in a couple of hours noted by Silly Moustache as causing his guitars to buzz should not effect a stable wood as it can't loose water that quickly. So perhaps the woods are not yet at equilibrium?

It suggests different drying points for wood products that are shipped to different areas of the US. So the wood should be dried differently for a product going to Florida compared to Las Vegas. It did seem that the chosen drying process could make quite a difference to the long-term structural integrity of the wood, as the drying process itself can cause underlying stress fractures within the wood. Plus, woods containing volatiles (spruce?) can give false drying readings as drying is not uniform. All in all, it is a very complex process. Well beyond my pay grade!!!

Last edited by Robin, Wales; 04-04-2020 at 06:58 AM.
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  #36  
Old 04-04-2020, 08:37 AM
rstaight rstaight is offline
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The soap dish pictured is what I used to use until we had a humidifier installed. It uses the heating duct work and is plumbed to a water line.

I just threw the dish in the case under the neck. Once everything got hydrated, I would need to wet the sponge once every 4 to 5 days.

The beads were developed to put in flower pots for a slow release of water.
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  #37  
Old 04-10-2020, 07:53 AM
Silly Moustache Silly Moustache is offline
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Originally Posted by Robin, Wales View Post
30-33% seems incredibly low for the UK? Have you tried simply opening a window? The Met Office is giving 58% for London today. And 74% for me over here in Wales.
Robin,
we always have windows open when weather permits and it certainly does right now. All back doors and widows are open, and today RH inside my newish 40 year old well insulted house is currently IRO 30%.

The BBC Weather site does indeed indicate outside RH of 49% but it is certainly nothing like that in my house which is also full of fresh cut flowers!

We are close to the south coast with the prevailing wind from the English channel, but it is windy, and as my seed trays have just demonstrated it dries things out, even since i watered them four/five hours ago.
I've put all my guitars in their cases them that have'em, with homemade humidifiers and "guitar Nomad" jobbies but I'm short of two which are taking ages to arrive from amazon.
In the cases the readings are in the low 40s.

Two guitars that hang on my wall in my study seem to be fine s they live there all year round, and are the oldest ones - maybe old wood isn't so finicky?
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  #38  
Old 04-10-2020, 08:34 AM
Malcolm Kindnes Malcolm Kindnes is online now
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The air certainly does seem to be very dry at the moment. I live in the north west of Ireland, generally known to be damp, but at the moment the outside humidity is 42%. I've just returned from a winter in Vietnam where the humidity was generally 80 - 90%!
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  #39  
Old 04-11-2020, 08:36 AM
Malcolm Kindnes Malcolm Kindnes is online now
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32% today, remarkable for April in Ireland!
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  #40  
Old 04-11-2020, 09:17 AM
Robin, Wales Robin, Wales is offline
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32% today, remarkable for April in Ireland!
That's amazing! I'm sitting here across the Irish Sea and my room is at 70%
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  #41  
Old 04-11-2020, 01:35 PM
Malcolm Kindnes Malcolm Kindnes is online now
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That's amazing! I'm sitting here across the Irish Sea and my room is at 70%
It is strange alright. Apparently it is going to rain here overnight, it will be interesting to check humidity again in the morning.
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  #42  
Old 04-13-2020, 06:46 AM
Malcolm Kindnes Malcolm Kindnes is online now
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I forgot to post yesterday but today it is sunny and dry again and with my French Windows open the temperature is 23.2c and 30% humidity! This is on the side of a hill, overlooking a lake in the north west of Ireland, something strange is going on.
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  #43  
Old 04-13-2020, 07:41 AM
Robin, Wales Robin, Wales is offline
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I forgot to post yesterday but today it is sunny and dry again and with my French Windows open the temperature is 23.2c and 30% humidity! This is on the side of a hill, overlooking a lake in the north west of Ireland, something strange is going on.
Yep - there is something very strange going on there? I would have thought your humidity would be a lot higher. What does the Met Office give you as the humidity outside?

Today we are at 15.5 deg C and 67% in the room where I keep my guitar. Just the other side of the Irish Sea and only a few deg south (about in line with Dublin)



Just looked at the Met Office for here and it is giving 48% outside at present but going up to 75% by 9pm and then 86% overnight.
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  #44  
Old 04-13-2020, 08:53 AM
Malcolm Kindnes Malcolm Kindnes is online now
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I am quite a long way from Dublin, the nearest place I can get a fix from the met office is claiming 47%. The wind is from the east, which is always drying and my house is in a very exposed location. My house is modern and very well insulated with underfloor heating, and I thought maybe I am heating up dry air causing it to become dryer so I moved the hygrometer outside into the shade. Guess what, the humidity dropped to 28%! As our friends in the US would say "go figure".
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  #45  
Old 04-13-2020, 09:42 AM
mcmars mcmars is offline
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Default Bovida bags work best for me

I live in American SW where outdoor humidity can drop as low as 6% at times. I have a central forced air heat with $1000 add on humidifier that was a waste of money and might add an extra 3-5% of humidity at most. I keep 2 small humidifiers running constantly, hang dry all my clothes and wet mop my wood floors sometimes 3 times a day if needed. I always keep my solid wood guitars in their cases as I have learned that leaving them on stands or the wall will result in damage or change set up. I have keep my home between 40-50% humidity and find I do not get winter colds or flu like I used to without humidity. But I learned hard way, it is hard to maintain a constant humidity in my home and have suffered problems if I left my guitars out of their cases.

For case humidity, I have tried all kinds of systems, soap dish or baggies with sponges, oasis humidifiers, etc. But they require weekly maintenance which becomes problematic with travel or if you neglect any of them for any length of time.

Now I order the bovida humidity packs on amazon in the 20 pack size and keep 2 in soundhole and 1-2 at top of case under the headstock. I can get a few months out of them, but I also rehydrate them by putting them in gallon zip lock bags and layer then with thin wetted sponges like building lasagna. It takes about 4-5 days to rehydrate them and if you use the thicker sponges then they bloat up to much, but small 1'2 thick 3X5" sponges like you can by on amazon in bulk hold just the right amount of moisture and when they dry out, the bovida bags seem about back to normal or maybe slightly larger. It helps to rehydrate them before they totally dry out and I bet the guitars stay more stable that way. The sponges have antibacteria and mold treatment which helps keep them fresh, but after a few uses, you might need to rotate them with new ones and let the old ones go to sink duty, just to be safe.

If anyone has a better system, I would like to know, but this is best way I have found living in desert conditions.
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