Hygrometers

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Alf

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Up the proverbial creek
Folks,

Having finally cleaned up my timber storage facility (fancy name for cubby hole in the w'shop :oops: ) I can now insulate all the corners I missed first time round, possibly swipe the de-humidifier from the house and finally clear the wood out of the guest room... Hooray. But I have a dilemma.

How will I know if the timber is fit for use in the house? At the moment I work on the principle that if it's been in the house for a while, it'll be at the right M/C. Not the case with stuff stored elsewhere of course. I think a thermo-hygrometer such as these would be the best answer, as then I can get the storage area RH correct rather than having to check each piece with a moisture meter. Added benefits include it being cheaper than a MM :wink: , no invasive pin holes in the wood and also the meteorologist in the family can use it.

So am I on the right track, or all wet? (Ho ho...) And if I am (on the right track that is), would the second one down of those I linked to be okay for the task? The secondary sensor could take the weather reading outside the w'shop I thought, and the min/max memory would be handy for that too. On the other hand, is digital a bit of an overkill? :? Having a hygrometer in the workshop has been mentioned in the past, but details seem a bit thin on the ground and it all makes my poor neanderthal brain hurt anyway... :cry:

Comments and personal experience welcomed, derisory laughter ignored :wink:

Cheers, Alf
 
hmmm......

just moving to a new house and guess who gets the detached garage :lol:

I was thinking about this (point well made).

On one hand we got some chaps in here suggesting that your workshop be well ventilated (to stop the accumilation of dampness from breath/heating etc), and on the other i hear of people putting dehumidifiers into the workshop.

Surely if you have a well ventilated workshop you may as well stand the dehumidifier outside :shock:

what do most people do?
what are you SUPPOSED to do?
what is it BEST to do?

the linked thermometer/come humdity sensor looks a great bit of kit for the price!
 
Alf, I have just built a conditioning box. It is about 8'x4'x4' and lined with polythene. The base and top are insulated with 1" polystyrene. There is a RH gauge and a temp gauge (bought from garden centre) mounted on a window in the door. A small dehumidifier is placed inside. With it running I can bring the RH to 45% at 20 degrees. I have found that when I run the dehumidifier constantly for a couple of days,with some white oak that I had just bought, surface cracks will appear. I now cycle the dehumidifier on for only a couple of hours a day to retain the RH at about 60%.
Testing the oak with a moisture meter, it is reading between 7-8% equating to an actual MC of about 8.5%.
unfortunately you need a Moisture meter firstly to find out at what MC your wood is at and then to access it until you get it to the figure wanted. The RH/Temp gauge is used just to find out what the conditions are in the box at that point in time and do not really tell you what the MC is.
IMO it is the constantly moving air in the box which will dry the surface too quickly, as when wood is placed in your house the air is basically still.

I decided to try this idea after posting on the 'other' forum and talking to Scrit who already uses this system.

Hope some of this makes some sense as I still have a lot of learning to do about how the different woods will react using the box.

Phil
 
Hmm, lots more to think about. Thanks fellas - I think... :? :shock: :lol:

Phil, my theory was that if I knew the R/H and temp in the storage area was the same as in the house (which is already known), and the timber was in there for a reasonable length of time (as it always is, 'cos I take so long to get round to doing anything :oops: ) then the M/C would naturally gravitate to/stay at the level that was comfortable with those conditions, rather than fluctuating as it would do now if it wasn't in the guest room... If you see what I mean? If you do, explain it to me would you..? :? I've managed without knowing the exact M/C of the timber up 'til now with no problems -touch wood- , I just need to know "this is at the right level for its final destination" rather than actual figures. BTW, was the oak kiln dried that did that? Rather a worrying tale :shock:

Cheers, Alf
 
Alf,
I did the same as you for quite some time but dragging wood in and out of the workshop is a pain. The workshop is normally about 85-90%RH and about 10 degrees. I have maple in the wood rack which has been there for about a year and a half and it's MC is now about 12%. The oak which I just bought is about 8%, so after roughing it to size the box is only used to keep it stable and not to reduce the MC any further, but the maple will need to stay in the box longer until it is reading 8-9%. The moisture meter has allowed me to know when I can work the wood so there is no surprises in the wood movement deptarment. Without a meter we can only guess as to what level the wood is at. You can get away with wood at about 11% in rooms which are only heated intermittently.
Probably the most important point is where you buy your wood. If you can trust the supplier on the MC he quotes,how long he has had the wood in storage and where it as stored then you may be able to get away without a meter.
Unfortunately I find it difficult to get a good supplier for all woods and find that species vary from suppler to suppler.

Phil
 
Alf
This may help - I've been looking at the same thing:
http://www.woodbin.com/ref/wood/emc.htm
So if you know the RH - the wood should settle to the EMC - not sure how long it takes so would be handy to borrow a moisture meter to test initially.
But I just keep my shop/wood at ~70%RH and the temp is ~10 degrees. So the kiln dried wood shouldn't be absorbing too much moisture.
Cheers
Gidon
 
Alf":1vu2jhbv said:
Folks,


How will I know if the timber is fit for use in the house? At the moment I work on the principle that if it's been in the house for a while, it'll be at the right M/C. Not the case with stuff stored elsewhere of course. I think a thermo-hygrometer such as these would be the best answer, as then I can get the storage area RH correct rather than having to check each piece with a moisture meter. Added benefits include it being cheaper than a MM :wink: , no invasive pin holes
Cheers, Alf

HiAlf

I got something like that from Dixons for 14.99 a couple of months ago to help with my insulation and heating project and as observed my garage is dry enough to store the woodwork library so that I never have to leave it. I also know that my wood is stored in 20%-30% humidity at 22 degrress C or there abouts which is very reasuring when considering movement in centrally heated abodes.

Definitely a useful bit of kit.

.
 
Great stuff :D

Dave, excellent; looks like you could be saving me some cash :wink:

Gidon, bookmarked that link, ta very much :D

Tony, hadn't even thought of Dixons as a source; I'll check that out.

Thanks all. I'll probably take the plunge then, and maybe look into moisture meters a bit more as well. Although prising the wallet open for one tool without a blade is bad enough; but two...?! :shock: :lol:

Cheers, Alf
 
Folks,

I can now say with confidence that the humidity next to this computer is 54%, as my order from Maplin arrived this morning. :D Thanks very much for your help, and especially Dave for the link. :D

Cheers, Alf

Likely to be obsessively measuring the R/H of every room in the house for a while, until the novelty wears off :roll:
 
ALF,

You set me off wondering about my workshop also (so I bought one) - my workshop last night was 65% but it was raining outside - I did come in with wet shoes, and I have been using a waterbased treatment for the base of a beehive in the workshop (and drying it) so I am kinda hoping it should go down.

Adam
 
Alf,

Glad to be of service :lol: just to warn you, having bought the Hygrometer I then ended up going to Wickes and buying their mid range dehumidifier £109 :cry:
But the results are good the humidity is still higher than I would like in the workshop but I am throwing out ~8 litres of water a day 8)

Is the water from it distilled?

Roll up roll up get your distilled water here very reasonable rates :wink:
 
The water is in effect distilled and can be used as such - eg for mixing stains/finishes that might be affected by minerals in tap water.

However, if your shop is like mine, the dehumidifier becomes so clagged with sawdust that the water soon starts to look like soup and you need to filter it to use it for anything.
 

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