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My shop is far to big cold and damp to store wood for and build instruments in. I've looked at the cost of turning it into a space for this and it is beyond what i can afford at this time. So I want to turn one of the rooms in the house into my instrument space.

This to needs climate control but I think it would be easier to do one room instead of my whole shop. The room is about 10 foot by 12 foot. What would be needed to control the relative humidity of the room? What do you use. Here in Wales we have a relative humidity of about 98% so i'm assuming it would be as easy as a dehumidifier but surely there must be some kind of controls and monitoring system one needs to keep it at a constant. Its desired to be at about 45% right?

The other thing i'm interested in is the temperature. From what i can tell from all the reading i've done temperature is not as important as long as the relative humidity is at 45% is this true or is there an optimum temperature as well? I'm on a limited budget so DIY systems are more then welcome. thanks in advance.

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Disappointment is an empty box full of expectation

Temp and RH are relative to each other like the dew point and temp are. Storing wood is one thing and acclimating wood to work it is another. You can sticker wood that will not be used soon in an environment that changes or is not totally ideal but working the wood is another story.

For us the ideal is to control the shop environment at 65-75 F at 40-50% RH. The reason for that is many fold but put simply is that is a good mean condition meaning that you will construct the guitar at a RH that is mid way between the two extremes it could likely encounter.

The temp and RH you glue up at is probably the most critical consideration because you want the wood to shrink or expand as little as possible once in the environment it will live in.

In your situation you will likely have to always dehumidify and yes there are air conditioning systems available with temp and humidity control sensors and built in humidifiers and dehumidifiers. That said they tend to be expensive. Typically for most of us, we run a stand alone humidifier in the dry months that we monitor once a day or so. (adding water as needed) and a stand alone dehumidifier in the wet months (empting water as needed) we then use individual heating and air cooling systems as needed.

10' x 12' is small, thus easier to control. That was the size of my shop until last June.
IMHO your best investment would be vapour barrier (4 or 6mil plastic) and good insulation in the room. It's something you can do on your own with little investment in materials and time. After that a small dehumidifer and a heater should take care of temp and RH without much trouble.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

It is an internal room, in a solid granite building on the main floor. I have insulated and vapour barriered the ceiling but the walls don't need any treatment as they are solid and not exposed to the outside of the building on any side. Are there any measurement devices one can get to monitor the room? thanks for the replies so far.

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Disappointment is an empty box full of expectation

The Caliber III is a low cost hygrometer many of us use to monitor humidity levels because of it's accuracy. You can order one of the calibration bags to check the accuracy, too.

http://www.amazon.co.uk/gp/aw/d.html/re ... B0007W1EA6

James I have to disagree. I bought a Caliber III because of everyone's recommendation and thought the world was great, until I built a sling psychrometer after JJ posted his tutorial, just to check ya know. I was dismayed to find that the Caliber III runs about 12-14 points lower than the actually RH. I bought a hair hygrometer not long after and found it runs about 2 points above the sling psychrometer.

I leave the Caliber III on the wall as a reminder that digital does not mean better.

Craig put together and excellent tutorial on making your own hair hygrometer. http://www.anzlf.com/viewtopic.php?t=47

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Aoibeann

...or print out a chart, get a vacuum cleaner, a pair of mercury thermometers, and bit of scrap cloth and water. That works too, and it's pretty cheap. Does require more than just looking, though.

Lillian, that's terrible. I'm sorry. Mine has been within two since I got it three years ago. I know that they fluctuate from one unit to another. I think what you point out, and what's important, is that we check somehow.

You are right James, it's always good to check. The unfortunate thing about the Caliber III can't be adjusted.

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Aoibeann

my god Lillian that is brilliant. How do you know what's what on it thought. The one the picture only has a few lines on it. I suppose he has calibrated it to something? Its not much of a tutorial though is it, its much more of a show and tell. If the hair is dyed does it have an affect on the accuracy? my hair isn't long enough and my partners is down to her waist but it is dyed. I suppose as long as it is calibrated to a meter it will be ok?

I'll have a go at making one and playing with it. Thanks so much

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Disappointment is an empty box full of expectation

could someone specify on the type of card that is
and the weight of the coin (if it matters)
and how the hair is attached
thanks

Tomas you might want to contact Craig directly - my memory says that he is one of the only ones who has made a hair hygrometer and I think he originally turned us on to the idea.

What Lillian said about the Caliber III is correct and I did a study and found my 2 Caliber IIIs to be about 9% out and this is the important thing in the range that we need to monitor. Doing the salt test and checking them at 75% is useless in as much as at the range that we desire, 42 - 48ish RH it can be way off...

What I am trying to say here is that calibrating hygrometers I found to be far more complex than one would think. If we do calibrate a hygrometer and it appears accurate in say the 45% RH range there is no guarantee that it won't be 20 points off in the 79% range. So... what this means is that when we do our wet bulb tests to check and/or calibrate a hygrometer the shop needs to be in the desired range to assure accuracy of the test.

Here is a thread on the ANZLF of using a wet bulb to calibrate an Abbeon hygrometer: http://www.anzlf.com/viewtopic.php?t=2116&highlight=hygrometer

Also my former shop was about 11 X 11 and just another bedroom in a condo. I used a dehumidifier and humidifier as required. In the warmer months when the humidity was higher and the dehumidifier was running the thing put out so very much heat that the room was in the 80's even with central air conditioning on. I had to work in my boxers and even then it was not pleasant for longer sessions. Just be aware that if your dehumidifier is going to running often and your room is pretty small it's going to get warm in there....

Also dehumidifiers usually won't work well if the temp is below 70F so there is the problem - we can remove the moisture but it is replaced with heat.

Your best bet for monitoring the humidity in your shop is a wet bulb test which can be as simple as a couple of thermometers. Sling psychrometers are the same idea and work well so long as you don't hit your dog in the face with it.... Once you have one of these a used or new Abbeon that can be calibrated to the results of your wet bulb test and recalibrated as required will serve you well.

If you want to learn more there are tons of posts in the archives about hygrometers.

Good luck.

You'd be surprised at how thermal bridges can cancel out whatever insulation you have put on the ceiling, or anywhere. Moisture seeps from everywhere, including the floor.
In the production shop I was working in, the assembly room was called "the bubble". A 2 x 4 structure covered with 6 mil plastic on all sides. This is where the plates are braced and the boxes assembled. Even though the rest of the shop was RH controlled, "the bubble" was tightly monitored to stay at 45%RH 70ºF, at all times.
The discussion about hygrometers is fascinating. But if your room is not properly insulated with a tight vapour barrier, even the most powerful dehumidifier will struggle to keep things within the desired RH range.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I don't know what part of the world you live in Laurent Brondel, but in mine what you are suggesting is futile. Granite walls are meant to breath if you stop that process you begin degrading the wall, it is as simple as that. Being that i lived in Canada and am in fact a journey man carpenter as well as a journeyman bench joiner, trained and ticketed there, I do understand the construction process very well. I have built several of my own homes above the standards of quality 2000 while in canada as well as installed my own HRV and heating system in them. So it isn't that i don't understand the need for a room that is 45% relative humidity and 20 degrees. It is that this is what i have to deal with and want the best possible solution towards making it as close as i can without having to bulldoze the house to achieve it.

I was going to tear down the shop and rebuild it so that it can be properly regulated but the cost of doing that isn't worth it at this time, nor is it affordable. So i was going to just use my shop for all the rough work and do the assembly and fine work in the house. In a perfect world we'd all have the money to build the perfect shop and have the best equipment and be able to leisurely work and people would throw their money at us and elevate us to rock star status.... but here in the real world we do the best we can and that is what i'm aiming for. thanks

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Disappointment is an empty box full of expectation

Be aware that you should give the wood 10-30 days or more to acclimate to a given environment. So if you plan to start assembly of an instrument in a different environment than it was stored in, bring it in, sticker it and allow it to acclimate.

The wood will be stored in there as well. It will make short trips out to the shop to be thickness sanded, and neck blanks will be taken out to be rough cut on the bandsaw and then brought back in. There is plenty of space to store wood and and curing neck blanks etc... Right now I don't have to much suitable wood. But want to start stocking up laminating necks etc... I want to get the space ready for this endeavor. Thus the thread...

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Disappointment is an empty box full of expectation

I fail to see how a buttoned up internal room will degrade your granite walls, or anything else for that matter. I attempted to give you a simple, effective solution. Short of this I am afraid that with 98% humidity outside as you seem to suggest, every effort at controlling RH inside will fail.
BTW I live in Maine, USA as my signature suggests, 4 hours from Montreal, Quebec.
RH and temp are all over the place here, depending on the season, and the year.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I think this sums it up Laurent Brondel


Some people get hyper focused on one aspect that has relevance to themselves. I tried to impart upon you that i'm not just some silly person who has no education in such matters but you seem to persist on the same vein. I doubt very much that i won't be able to make the space suitable without tanking the room. There are differences in building practices and methods from the USA and the UK and especially those that are very old buildings like the one we live in. People destroy these old buildings all the time trying to modernize them. I can see how you don't understand and that is fine because it isn't within the scope of this thread nor within my patients to explain it fully.

The scope of the thread has to do with climate control. I have done all i can with the construction now it is up to mechanical devices to bring it the rest of the way. That's all i'm looking for. I would find it very difficult to believe that such a small room cannot be mechanically adjusted even in the conditions i've described. I have a dehumidifier on it's way that can be adjusted to what ever RH is needed so it is just a matter of having an accurate reading, and this seems to be a problem no matter where one lives so this is why the thread was made.

I have a 20 by 40 shop that I would more then happily tear down and rebuild properly in my mind to meticulous standard for my purposes but times are a bit tough so this will have to wait till such time it can be afforded. Thus moving to a smaller unused room in the house that would be easier to control. I made it clear in my OP that i didn't want to rebuild.

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Disappointment is an empty box full of expectation

Mr Warwick, I got the vague sense that you attempted to insult me before, and now it is done. You may have to explain what the purpose is.
As far as I am concerned you do not understand the basics you mention. You efforts will be similar to pissing against the wind or trying to dry yourself under the shower.
If you are so well versed in construction (which I doubt), framing a simple 2x4 structure inside a 10x12 room and stapling 6mil plastic over it with a revolving door will take less than an afternoon of work and under $100 in materials.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

Scanning over posts, so forgive if I repeat.

As posted some months ago by others, one thermometer is enough. Hang it with the cloth on dry in front of the fan in your shop all the time. It will have the dry bulb temperature. When you want to check RH, wet the cloth on the thermometer, leave it in front of the fan and wait until the temperature stabilizes for the wet reading.

If you actually sling the psycrometer in a shop, eventually you will hit something.

Do not use mercury, expecially if you are slinging it inside. When it breaks, you will have a health hazard. There are plenty of cheap, non-mercury thermometers that are fine. Remember, you are recording a relative change in wet/dry temperatures. If you look on your chart, you will see that one degree off on the absolute temperature is not importatant. The practical consideration is to get a thermometer that is not insulated, i.e, you do not want the termometer inside another tube. It will just take too long to get the wet temperature to stabilize.

I found this site when looking up hair hygrometer on google.
http://www.exploratorium.edu/exploring/ ... ivity.html

"Here in Wales we have a relative humidity of about 98%" You may want to put one of these hygrometers together for your room. Unless your worried about the destruction of an old piece of hair.

I don't know what you or Laurent have taken offense to. I only agreed with him that he failed to see, and expounded that it was off topic and a waste of energy to continue thrashing out a futile topic. maybe you need to reread as well. I've been very restrained and tried to keep the thread on topic nothing more. I am very literal in my speech and mean nothing more then what has been said.

If you or Laurent are looking to start something i suggest starting it with someone else.



I have no interest in such games

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Disappointment is an empty box full of expectation

like i said start it with some one else

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Disappointment is an empty box full of expectation

Let's back up a bit. This is an excerpt of the OP:

I won't comment on the syntax or the grammar, or even the spelling in other posts. However the question I tried to answer is:
"What would be needed to control the relative humidity of the room? What do you use."

Then this:

Should I feel flattered, is it a compliment?
Furthermore I would like to know what is incorrect with my suggestions.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

If you live in a swimming pool and want to stay reasonably dry then you are going to need some sort of dry suit containment. Just seems logical to me