Humidity Temp In Shed

[GREGMW]

Just curious,How do you guys control the Relative humidity in you work areas.

I am going to start building a Stewmac Accoustic Kit,and my shed is just a single timber garage.

Stewmac suggest that the enviroment be ,70 degrees and 45-50% humidity.

At the moment we are averging 80% humidity down here.

Am I worrying over nothing .What do you guys do? I am thinking about a cheap Air Con unit,but it all starts to get expensive.

Your input would be welcome.

Regards

Greg

[George Brown]

as this is a kit i would assume that the thin pieces of wood would be quite prone to warping and think its definatley worth worring about, im not that much of and expert on wood but as its going from a low to high humidity its obvious that it will absorb so mositure, what affect this will actualy have i dont know as the affects of taking up and giving out mositure could be different for all i know, but id still be worried about warping

[mammoth guitars]

Bring those pieces back into the house and don't leave them in the shed when you are done.

[ToneMonkey]

How about a dehumidifier?

I'll ask the missus tonight what she does, she has to monitor the RH at work and is in charge of not letting the painting and stuff get damp.

Did you measure the RH outside? If that is significantly less, then circulating the air and having an output fan may be a good idea.

EDIT - I found that building in the spare bedroom was far better than using the spider filled shed. Just go to to clean up more.

[fryovanni]

A wide change in humidity is tuff on wood. You should be careful to sticker the wood (if possible, this is a kit. pre-bent sides and such). The wood needs to aclimate as slowly as possible. After the wood has aclimated to your humidity. Try to avoid moving it around to different areas changing the humidity (again aclimation is hard on the wood). Drying wood in an environmet that is 80% RH will be extreamly slow. Your biggest issue will be glueing wood at 80%. It is best to glue in 40-50% RH. Higher humidity will make for poor curing. If you can control the RH in your workspace and keep it at a reasonably STABLE level (preferably around 40%) you will do much better.

Peace,Rich

[MP63]

GregMW,

I feel you frustration.

I too had the same dilemma.

I used my garage, but I was at the mersy of the weather. Especially when working on an acoustic guitar.

It became so bad, the changes in humidity, that I built a work room in the garage.

It still gets changes in humidity, but not as severe and not so sudden.

To keep the humidity constant and in control would cost me a fotune in eletricity bills.

The only rational to keeping the area constant would be if I was a professional builder, then I'd have a whole building (small) for it.

These are some of the obstacles we as amateurs must overcome.

Maybe, doing the assembly in a room in the house and doing the cutting and sanding outside.

I, myself, am trying to eliminate as much sanding as possible and go to using scrapers.

Remember, dust will get EVERYWHERE. In your lungs too.

The first guitars I built were exposed to all the elements as I built them in a garage with the dorrs opened all the time. Rain or shine, and you know what? They play great and keep their integrity as well as my Taylor.

Go figure that one.

Just because the weather goes from 40% to 80% humidity does not mean your wood will too.

The changes are small once dried properly, but it is enough to cause changes where the alignment of things will move a bit. All guitars will change with the humidity. Ask any Rickenbacker player about that.

I need to adjust mine at different times of the year.

[fryovanni]

GregMW,

I feel you frustration.

I too had the same dilemma.

I used my garage, but I was at the mersy of the weather. Especially when working on an acoustic guitar.

It became so bad, the changes in humidity, that I built a work room in the garage.

It still gets changes in humidity, but not as severe and not so sudden.

To keep the humidity constant and in control would cost me a fotune in eletricity bills.

The only rational to keeping the area constant would be if I was a professional builder, then I'd have a whole building (small) for it.

These are some of the obstacles we as amateurs must overcome.

Maybe, doing the assembly in a room in the house and doing the cutting and sanding outside.

I, myself, am trying to eliminate as much sanding as possible and go to using scrapers.

Remember, dust will get EVERYWHERE. In your lungs too.

The first guitars I built were exposed to all the elements as I built them in a garage with the dorrs opened all the time. Rain or shine, and you know what? They play great and keep their integrity as well as my Taylor.

Go figure that one.

Just because the weather goes from 40% to 80% humidity does not mean your wood will too.

The changes are small once dried properly, but it is enough to cause changes where the alignment of things will move a bit. All guitars will change with the humidity. Ask any Rickenbacker player about that.

I need to adjust mine at different times of the year.

I hear what you are saying and can agree that we don't have the luxury of expensive climate control. You are mistaken that the only rational to keeping a stable environment would be if you are a professional builder. I think you are trying to say that humidity changes won't destroy wood or change it's total moisture content in an instant. You are correct in saying that.

When wood is stable it means that the wood is not drying significantly anymore. It is only making slighter changes to it's surface moisture content. When you introduce it to a significantly higher or lower moisture climates it needs to aclimate (usually only takes a short period of time). After it has aclimated it is stable again. These are small changes if the wood is well dried already. Note everything I am saying here is stabalize. Keep things from changing a lot. If your area has 50-60% humidity 90% of the time, and them you get a couple days of 80%. Things will be fine when it settles back to your normal humidity level that the wood is used to. It may increase it's surface content slightly for a day or two but it will release and be back where it started in short order.

When you are talking about drying wood, curing glue, curing paint. High humidity has a big impact on cure rates. You should not try to do these things when the humidity is very high if you can avoid it. A bad glue joint on an acoustic may hold for a few years and then all the sudden you start getting high fail rates. I am not trying to say your joints are all doomed if you don't glue in perfect conditions. I am just saying be mindful and try to do things as best you can.

Peace,Rich

[MP63]

Thanks for the information Rich.

Man, right now down here where I'm at, the weather is just too crazy to predict anymore.

It's just a crap shoot when planning any painting or glueing.

We try to keep the environment stable, but how fruitless it is.

Ah, to have the big bucks for the climate controlled shop, but, we manage and we persevere.

That's the challenge, and therefore, the beauty of it all.

Thanks,

Mike

[Doeringer]

Put in heat and insulated last fall and put in a good window unit this summer. Doesn't get cold but stays comfortable. I'm averaging about 55%

[orgmorg]

Dehumidifier and an airconditioner.

If you think it's hot in the shed now, wait 'til you're cranking the DH full bore!

Between the two, you should do ok, but yeah, it can be expensive if you have no insulation.

If you can get the foil-faced foam board, that makes for good insulation in a shed. Put the foil to the outside to reflect radiant heat.

As to the wood, picture it like this: Wood shrinks as moisture leaves it. You get it at 6-8% moisture content. You can keep it this level at 45% humidity. At 60% humidity, it will be about 12% moisture content, and a tad larger. At 80% it will be pushing 18%MC and even larger. If you assemble the instrument at this state, all the parts will shrink when it is kept in a house at real low humidity. Wood also shrinks at different rates along its 3 axes. Tangential (across a flatsawn face) shrinkage is often twice Radial (across a quartersawn face) and it hardly shrinks along it's length at all. An acoustic instrument contains wood going every which way, so you can see what happens here.

You could also consider just using the shed for the messy portions of the job and try to keep the wood in the house as much as possible.

I have one insulated room in my shop I keep at 45-50%. I keep the A/c set at 85 and it feels good in there! That should give you an idea what summers are like here.

Edited July 26, 2006 by orgmorg

[GREGMW]

Thanks for all the helpful info.

I think I will try building a small room within the shed,with unsulation, and a small AC unit in it.(if nothing else,I will put the other computer in there !!)

I have watched the humidity over the last week and it changed from about 45 - 65 % and about 21 deg C

I have a lot of timber stored in the shed (Cedar,Rock Maple,Ash,Pine etc) and none of it really seems to move.I know its a lot thicker than the sides/back and top but if any thing this would be a good indication - I hope.

Thanks

Greg