How low is your acoustic action?

sev112 · October 2021

Mellish said:

@sev112. No, humidity is higher during summer. A dehumidifier knocks it down. You can set it to what you want, like 50% and it will keep the room close to that. You can get them from Curry's, Argos, Home base, stores like that

Wow, that’s amazing, I would have just presumed summer is hotter therefore dryer, and winter has lots of rain therefore wetter / damper.

blimey, if our whole top floor is 70% at the moment, god knows what it’s like in summer !

sev112 · October 2021

Just checked Wokingham historic meteorological data and the annual figures suggest

“The month with the highest relative humidity is November (86.79 %). The month with the lowest relative humidity is July (70.78 %).“

i.e. that summer is less humid than winter

Mellish · October 2021

@sev112. I use a dehumidifier where I keep my HD28. Without it, the room has high humidity in summer, low in winter. If someone wanted to get geeky, they could use a dehumidifier in the summer and an humidifier in the winter

sev112 · October 2021

Ta, well I must admit I’m absolutely totally confused now. Because that seems to be the opposite of what the local weather records suggest. Where do you live in the world / Uk? I wonder if that makes a difference to why your summer is wet yet ours are dry ?

Mellish · October 2021

I live in the East Midlands - Lincolnshire

Mellish · October 2021

@sev112 have you got an hygrometer? Put it in your room. Monitor summer and winter readings

sev112 · October 2021

Yes, got some yesterday - will be interesting to see

Mellish · October 2021

It's possible to get paranoid over humidity readings as @TheBigDipper pointed out. I just set my dehumidifier at 50% and let it get on with it. If I had an humidifier for winter, I'd set that the same

Cig35 · October 2021

sev112 said:

Just checked Wokingham historic meteorological data and the annual figures suggest

“The month with the highest relative humidity is November (86.79 %). The month with the lowest relative humidity is July (70.78 %).“

i.e. that summer is less humid than winter

Relative humidity measures how much water there is in the air compared to how high the water content can theoretically be. And warm air can contain more water than cold air. If the temperature in November is10C and in July 20C then those measurements mean that the water content in the air is roughly 50% higher in July than in November.

When the November air then enters a house and gets heated to 20C the relative humidity sinks to around 45% compared to the July air with a relative humidity of 71%. So on average the air in the summer has a clearly higher water content than the air in the wintertime.

sev112 · October 2021

So, as I’m learning loads from here and the past couple of days, when Taylor etc talk about keeping humidity 40-55, they mean total/normal/actual measurable humidity, and not relative humidity ?

Lewy · October 2021

sev112 said:

So, as I’m learning loads from here and the past couple of days, when Taylor etc talk about keeping humidity 40-55, they mean total/normal/actual measurable humidity, and not relative humidity ?

They mean Relative Humidity (RH) which is what Hygrometers measure.

Tannin · October 2021

sev112 said:

So, as I’m learning loads from here and the past couple of days, when Taylor etc talk about keeping humidity 40-55, they mean total/normal/actual measurable humidity, and not relative humidity ?

No. *Relative* humidity is the figure that wood cares about and the figure that guitar makers are interested in.

Most of the UK, most of the time, has humidity in the safe middle range. Some particular locations may require extra care. Most (not all, "most" of the yammer-yammer about humidity comes from the States where they have triple whammy: their climate has extreme swings because of the unusual continental geography, they like their guitars a bit on the flimsy side, and they heat like crazy in winter and cool like there was no tomorrow in summer.

sev112 · October 2021

Thanks, but that’s what’s confusing me

im in the south east, many miles from the coast, and our 4 rooms upstairs in a modern 18 year old house are all 70% , the en-suite is 80%.

I can’t understand why I have such high values ? I do think the extractor fan in the en-suite is rubbish, it just about holds a bit of tissue paper, and we have got black spots starting to appear on the en-suite ceiling, but the other side of the plasterboard in the loft is bone dry when I lift the insulation

ok, we dry clothes in a couple of the rooms in autumn / winter, and put towels over the bannister after showering, But none of that sounds any different ti the rest of the population.

Anyone any suggestions? Presumabky I can’t buy a plug in dehumidifier and use it in the en-suite ?

Tannin · October 2021

That's a bit on the high side. Not scary but worth looking at. Manufacturer-recommended humidity levels vary but some representative examples are 45-55% (Taylor), 42-50% and 13-28 degrees (Cole Clark), 40-65% (Furch), and 35-65% (Maton). Guild provide an "ideal" temperature (22 degrees) and humidity (45-55%) without saying what they regard as too extreme for safety. Maton go into some useful detail:

Maton said:

At Maton, we build all our guitars in a controlled factory environment of 50% relative humidity. We do this because we have established 50% as the level that will enable our guitars to best survive the humidity extremes found in Australia and around the world. This does not mean that Maton guitars are indestructible! Quality musical instruments are made from quality tone woods carefully dimensioned for optimum tonal performance, but they also reflect changes in humidity levels. Well seasoned timbers have an equilibrium level of moisture of about 8% when relative humidity (RH) is at 50%. If the relative humidity climbs to 80%and stays there for some time the moisture level in the wood will increase. In a guitar this will result in a swollen ‘belly’ and a high action. Conversely, if the guitar is subjected to 20% humidity for a long period the result will be a sunken belly, strings rattling on the fingerboard and protruding fret ends. In either case, the remedy is to expose the guitar to correct humidity levels until normality is restored.

Fortunately, relative humidity levels in Australia are generally between 35% and 65% and Maton guitars are well able to handle these levels. If your guitar is exposed to greater extremes than this you should take the following measures to minimize humidity damage by doing the following:
• In areas of high humidity keep your guitar in its case and store silicon gel packs in your case to help absorb extra moisture. (This will also minimise string corrosion.) Four grams of silica gel is the correct quantity to protect a
guitar so two packs will suffice. If you are unable to find silica gel you can use rice in a cloth bag to obtain similar results.
• In areas of low humidity fit a humidifying device to your guitar and leave it in your guitar when it is in its case.
It takes a few hours for moisture levels to rise or fall in the timber cells so don’t be afraid to play your gig, just don’t leave your guitar unnecessarily exposed to excessive humidity levels for long periods.

I can't see the point in dehumidifying the en-suite (unless you keep guitars in there).

But I don't like the sound of those black spots. It rather sounds as though it is lacking ventilation. Do you think the en-suite arrangement is driving up the humidity in the rest of the house?

It strikes me as a situation needing an openable window and/or a more powerful fan. Where does the existing fan exhaust to? It should blow the wet air outside, of course, but I've seen dodgy installations where the exhaust fan just blows into the ceiling space - i.e., not getting rid of any moisture, just spreading it around a bit.

Mellish · October 2021

@sev112 most dehumidifiers will control one room - if you keep door/window closed. I just control one room where my HD28 lives and I don't bother about other rooms unless there's signs of damp, then I'll put a dehumidifier there too

drofluf · October 2021

sev112 said:

Thanks, but that’s what’s confusing me

im in the south east, many miles from the coast, and our 4 rooms upstairs in a modern 18 year old house are all 70% , the en-suite is 80%.

I can’t understand why I have such high values ? I do think the extractor fan in the en-suite is rubbish, it just about holds a bit of tissue paper, and we have got black spots starting to appear on the en-suite ceiling, but the other side of the plasterboard in the loft is bone dry when I lift the insulation

ok, we dry clothes in a couple of the rooms in autumn / winter, and put towels over the bannister after showering, But none of that sounds any different ti the rest of the population.

Anyone any suggestions? Presumabky I can’t buy a plug in dehumidifier and use it in the en-suite ?

Have you calibrated your hygrometer?

this is for cigars (where they also care about humidity for storage) but water doesn’t care if it’s a vintage Martin or a Corona hand rolled in the thighs of a Cuban virgin https://www.famous-smoke.com/cigaradvisor/how-do-you-calibrate-a-hygrometer

I don’t think it needs to be 100% accurate; if you know that it reads 5% high you can then track changes in humidity which are not as important as the EDIT absolute displayed values.

P.S. realised there was some ambiguity in my use of absolute above.

sev112 · October 2021

Thanks for all the advice all

it’s quite funny with the 2 guitar cases being more humid inside ! I dried them both out with the hair dryer, got them down to 10 - 20%, aired them a bit, and put the guitars inside for a few hours. Took them out later that afternoon and the readings inside back up to high 60s. That was interesting I thought.

Today I’m experimenting with a big pack of silica gel that you microwave and put in ca4s which leak , and I have a PlanetWaves/d’addario pack coming today. And I’ve got one of those Unibond chemical tablet dehumidifier things in the en-suite, which is producing water since yesterday evening.

So little steps

drofluf · October 2021

Why not dry a case and see what the humidity is like later without a guitar in it?

Mellish · October 2021

Try putting the D'Addario pack in the case, along with an hygrometer, and leave it a few hours. It should read around 45% next time you check. But as @drofluf said, your hygrometer may need calibrating

drofluf · October 2021

drofluf said:

Why not dry a case and see what the humidity is like later without a guitar in it?

Sorry got distracted before I finished.

If for some reason the cases are very damp, although I’d be surprised if they both were, you’d be better off getting them properly dry before you put a guitar back in them.

Howdy, Stranger!

Categories

In this Discussion

Become a Subscriber!

How low is your acoustic action?

Comments