Workshop Humidity

[MARK.B.]

Can anyone please tell me what is (would be) the ideal humidity in a workshop .


Mark

 

[colinc]

the same as the humidity of the place your product is going to live in? Otherwise the wood will re-size as it adjusts.

Not sure that's so simple to achieve though.

regards,

Colin

 

[Phil Pascoe]

Mine's 90% at the moment. It could do with being less. (It's a bone dry building).

 

[MARK.B.]

Thanks Colin, i understand about the shrinkage / expansion and i guess it would be damn nigh impossible to achieve a match in every case,
i was more sort of asking what you guys here try to maintain in your work shops.

 

[liamscanlan]

Well... For lutherie, the recommended range is 45-65%. I don't know what folk do in general, but I try to keep my workshop within this range. I use a dehumidifier (continuously on) which keeps things stable and costs very little to run. I get no rust on anything and the wood stays ready for use (once stabilised). It saves me a lot of anxiety over thin and very expensive timbers moving too much.
Hth

Liam

 

[Racers]

Hi, Mark

My workshop is the garage, so I have to take the wood into the house for a week or two before using it, and not leave it in the garage at night.
Its a pain lugging every thing about, but it works.

Pete

 

[AndyT]

I'm in the happy position of having my workshop in one room of our basement. Because the other room houses a gas boiler, successive heating engineers have cut gaping holes in the front and back doors to the outside world. The effect is that the basement is very well naturally ventilated. Also, the temperature range is pretty small. In winter it's cool but not cold (good for hand planing) and in summer it's a pleasant refuge. The proof that it works is that wood does not move unduly and tools do not rust.

At present it's about 13 degrees C and about 45% RH (according to a cheap little hygrometer). That seems to be a good level to aim at.

(On the minus side I have no natural daylight and access is all down some narrow stairs, so it would not suit everyone!)

 

[MARK.B.]

Thank you all for the replies, it looks as though somewhere around 45% is the humidity to be aiming for.

Phil p that does look a bit on the high side,although saying that mine high as well around the 75% level,i think when it warms up a little i will have to have a look at making a few changes to see if i can bring it down.

Liam,i would love to have the skills and paitence to do the type of woodwork that you do,my attemps at making things appear very rough and ready compared to the work from others on this site, the cost of timber nowaday's does mean that keeping waste to a minimum is important.

Pete not ideal to have to move everything back and forth from garage to house, but as you say it works for you, swmbo would not be as understanding i once tried to rebuild a bike in the kitchen and it nearly ended in tears (mine not hers) yours must be very understanding

Andy i always wanted a basement workshop ,that is until the floods of 2007 left us living in a caravan for 18 months
45 - 50 % seems to be the target humidity level for me to aim for.

 

[Racers]

Hi, Mark

She understands I need to keep it in the house and the hall seems to be the ideal place.

That pile turned into this.

I still have loads of wood in the hall and up the stairs!

Pete

 

[Phil Pascoe]

After my mother died, my sister took antique furniture home with her, against a lot of advice - everyone was convinced the high humidity would cause problems. I think she got away with it because she moved it from Cornwall (damp) to Auckland (even damper). Eight years later, she's had no problems.
My workshop has a garage door so the humidity is uncontrolled - at very best it's about 65%, and that's not for much of the year. I must admit it's abnormally high at the moment - winter's usually a bit drier.

 

[MARK.B.]

A table and chairs like thate pete is a fair trade for allowing you to keep your wood nice n cozy

Phil can you insulate the door in some way ?

 

[Phil Pascoe]

Mark - Without sealing the building or heating it full time, I'd be peeing against the wind. That's the humidity we live with.

 

[Yetty]

Mark, the Yetty keeps his workshop humidity below 68% RH, aiming for 60%. Settled on these RH figures by hoping they are reasonable ‘middle of the road’ levels. But only do this when getting timber ready and during a project.

Newly purchased project timber has its timber moisture content measured over a few days, waiting for the readings to be steady i.e. timber moisture content in equilibrium with workshop.

Workshop humidity is controlled using a desiccant type electric dehumidifier. This type works well at lower temperatures and the small amount of heat generated is welcome! As para 1, the drier is only use when needed. Lots of projects made and never had any problems, so far, touch wood. Hope that helps a little.

 

[MARK.B.]

Thank you Yetty,does it cost much to run one of those dehumidifier's ?

 

[Yetty]

Mark, power used depends on the selected drying mode. Mine has at least two power levels, and several modes. I think power can be about 400 or 700 watts, and only when drying of course. Different modes determine the target RH level using internal humidistat and how quickly that is achieved. Being dessicant type, the drying effeciency stay pretty good at lower temps., where as I think the compressor types struggle more.

Sure, running this unit / above power costs money. But it is nothing compared to my timber and lighting costs, and worse the cost of fixing a warped project! Still, Yetty is happy, the power used puts needed warmth into the workshop when there's a project on the go!

Some advocate building design improvements, but for me that would be rather more costly, both cost and space wise. This works for me and I guess it depends each individual’s situation.

As previously mentioned there is little/no rusting of steel and ironwork, no obvious condensation. Surprisingly, I’ve found the workshop feels a few degrees warmer than actual, so I’m able to work at lower temperatures.

Sorry about rambling beyond your question, thought it might help.

 

[MIGNAL]

Luthiers aim for near 45% RH. That is considered a safe average but really it all depends on the environment in which the object spends it's time . The real danger is building/assembling at fairly high RH (say 60% +) and then subjecting the work to low RH levels. During the winter RH can levels can easily dip below 30%. That's when things may start to shrink and crack. It's much worse with the thin veneer type woods that Luthiers use though.

 

[JonnyD]

It's between 25 and 35 percent in my assembly room. I don't know whether that's in line with a house RH or not or if is a little low?

Cheers

Jon

 

[MIGNAL]

What are you measuring RH with and are you certain it's accurate? Hygrometers can be way out, even new.

 

[JonnyD]

It's a digital temperature station thing so maybe not fully accurate. If you move it outside it goes up to about 75

Cheers

Jon

 

[JonnyD]

Did a test today the digital station showed an average of about 24% humidity but varied throughout the day from about 30 to 20

The only other thing to test against was another digital tester which has a probe and used to be used to test the humidity for drying corn so I assume it is more accurate the temperature was the same on both units. This averaged about 32% but went as low as 27%

I assume if it stays around 30 or just over it won't be too dry.

Cheers

Jon