dangerous humidity levels?

[Mo_coon-catcher]

My room I have my bows in is running a pretty low humidity. And it’s got me to thinking. What are the humidity levels that you all consider to be detrimental to a bow? I know that wood species makes a difference. At what levels do you all stop usincertain wood species from them becoming too brittle or too spongy? My room has been running from 75-80 degrees and about 12-20% humidity. Ours summers usually have my hygrometers reading about 40-50% in the house.
No idea if it makes a difference or not, but I don’t like to use anything that’s not hickory or backed at leas than 25%. I may be over cautious though. Same with that I won’t use a bow that has any iffy spots in te back.

So what’s your all’s opinions on humidity levels?
Kyle

[Badger]

  Yew is about the only wood I really worry about but I don't have to deal with that low of humidity. I wouldn't want my osage going below about 7% or so.

[George Tsoukalas]

I like ...
6-8% for hickory
8-10% for all else.

I use a moisture meter,

Jawge

[willie]

Knowing how dry or damp your wood is MC% wise is a bit different from knowing what RH to keep the storage area at.
the bigger the RH level differences and the longer the bows are stored, along with the how well the bows are sealed, all make a difference in how fast the MC of the wood changes.

the moisture in the air you have at 75-80 F. and 12-20% RH is the same as 50% RH at 50F.,  so just keeping them in a cool spot could make a big difference in how fast they are drying or taking up moisture.

[Selfbowman]

All I know is Osage does not seam to like Colorado and Utah climates . Probably Arizona Nevada some other low humidity places. Just an opinion though more than proof. Arvin

[PEARL DRUMS]

If the actual RH reading goes below 30-32%, I don't bend/tiller any type of wood. I prefer 45-60%. Our home was in the 20's. I started running three humidifiers and about 4-5 gallons of water per day just to get it up to 38-40%.

[Danzn Bar]

At 65 degrees F
RH@50%=9.3 EMC
@40%=7.8
@30%=6.2
@20%=4.5

Pearl I'd say your in the ballpark 

[Danzn Bar]

Check out wood  Equilibrium Moisture Content on google

[PEARL DRUMS]

More over, its not good for the folks in the house or the house itself when you start talking RH in the 12-20%.

[BowEd]

In the teens is too dry to me.Those RH numbers at warm temps are pretty sketchy to build bows at.Like said at least above 30 to 35 per cent is a bit more safe.
The colder/the longer these winters get the dryer it gets of course in most areas.I had a cousin in New Mexico telling me RH at 10% was not uncommon at all.Here in Iowa it would be.

[willie]

.I had a cousin in New Mexico telling me RH at 10% was not uncommon at all

Ed , I have no doubt that there is a difference betwen NM and Iowa, but I believe it would be better to call it a difference in absolute humidity or just  humidity. When we speak of relative humidity, without mentioning the temperature, it is a bit like saying my bow pulls 45 lbs but not mentioning a draw length. The weather folks never cite a relative humidity, but usually use something more definitive like wet bulb temp.
As an experiment, these last few days the thread has been going, I have moved my humidistst from the window sill behind the counter, to a spot in the middle of the counter about two feet away. the relative humidity reading changes with the temperature
reading, but I doubt the water content in the air changes.

I just keep my bows in a cool spot, and they do not seem to dry out.

[BowEd]

Hmmmm.I suppose you mean dew point as the wet bulb temp.When the dew point and temp are closer to the same the humidity is higher.There is definitely more moisture in the air at higher humidity levels.
Leaving wood outside humidity levels will never endanger wooden bows to be overly brittle and I dare bet not below 12%.It's only when we take them inside is when that danger can happen especially in the winter time.
You can have very low humidity levels even at cold winter temps outside.I can watch ice disappear over time with wind as a helper in below 0 F temperatures.The ice evaporates without melting into the air.

[bjrogg]

The dew point is the point where the moisture level of the air can't be held by the temperature of the air when they are both matched. If temperatures and dew point are the same it means visible moisture in air either rain or fog. The higher the temperatures the more capacity for air to hold moisture. Very cold air can't hold much moisture and with furnace or wood stove going even the little moisture in the air is removed. I like my farm shops in floor heat for a constant heat that doesn't overly dry the air. We usually move enough equipment in and out that has snow or ice on it to add some moisture to the air also. The heat in the floor also dries the floor nice and makes working on the floor much more pleasant.
Bjrogg 

[willie]

Those hated slabs are nice.
Actually if you check the outside relative humidity in the winter cold, you might be surprised. Here The RH is 80%, although it is 10 F.  I suspect that wood kept outside this time of year at that RH, will  not soak up moisture near as fast as if it were summer, on account of absolute humidity being so low possibly?

[Mo_coon-catcher]

Makes me glad it’s warms up a bit and is thawing the snow putting a good bit of moisture in the air. Figured it would be a bit in the dry side for all but hickory. I have one bow of a temperamental wood that I need to test shoot some more. So I put it in my truck to gain some moisture before I shoot it

Kyle