how much humidity

[jeffp51]

Hi all.  I just got back last saturday from a month in Berlin, Germany.  Before I left, I moved all of my staves from my basement to my newly completed garage/shop.  This being Utah, it is really dry, but it was worse in the new garage.  The meter showed 9-10% and about 90 degrees.  I figure that is too dry, so I moved a few staves back to the basement and set up the humidifier.  I have that room sitting at about 70 degrees and 55% humidity.  My question is, how humid do you all like to keep your staves when you are working them, and how long should I keep these staves rehydrating before I try to work them?  I have one yew stave and some osage, as well as a couple white wood staves.

[Pat B]

Depending on the wood but both osage and yew prefer 9% to 11% M/C as do most others. Hickory is in a league of it's own and preforms best at about 6%.

[osage outlaw]

I noticed I was getting better performing bows when I finished up a few blanks that I had stored in the house for a year or two.  Our house stays around 70 degrees and 50% humidity.  Similar to your basement conditions.  Last fall I roughed out a bunch of bows and brought inside until I'm ready to work on them. 

[DC]

I think 70 and 55 is pretty good. I would leave them in the new environment at least as long as they were in the dry one. Reasoning that it will take just as long for the moisture to get back in as it took to get out. May be wrong there. You could weigh them and wait for equilibrium. You may already have this   http://www.csgnetwork.com/emctablecalc.html

[George Tsoukalas]

This is what I like. 6-8% is good for hickory. All other woods 8-10%. Jawge

[aaron]

using the link DC provided above, you'll see that wood stored at 55% R.H. anywhere from 60 to 100 degrees yields  a wood moisture content in the range of 9.5-10.3. In the graph below, the blue line's width covers a range of temps from about 50 to 100F.

[aaron]

so, wood in your garage will stabilize at under 3%- yikes! What we don't know yet is the answer to your question of how long will it take to stabilize in the new environment.

[jeffp51]

Yeah, welcome to the high desert. I am thinking I will leave it at least a month, since that is how long it sat in the garage. But I am anxious to get building again, so I am not sure I can wait longer than that.

Thanks for the link, that is really helpful.

[mikekeswick]

Interesting. The thing is that once you have a bow finished then it will also be heading for a low m.c. once out of your garage. I think if I were you I would use only hickory!

[jeffp51]

Mike, the finished bows have all been stored in the basement. The room is attached to the laundry room, which is helping with the humidity, and so far, everything seems to be fine. The trilam you sent still shoots fine, and I have an Osage selfbow I put hundreds of arrows through. Wouldn't mind some hickory, though.

[PEARL DRUMS]

I'll take the basement numbers all day and twice on Sundays. Our upper levels of the house run the same numbers all spring and summer. In winter it gets much drier.

[DC]

You can always put them in a plastic tube with a damp rag or something. You guys with low humidity have it sorta good, it's easy to raise RH, it's a PITA to lower it.  

[steve b.]

I broke this bow-in-the-making, today, because of humidity.  Its ash.  I had it at full brace, looking good, and ready to rawhide over the trapped back--after 3 days of careful tillering.  For some moronic reason I decided to put it out in the hot sun to get it good and dry before final testing of the tiller and then the backing.  I left it there for several hours.  It was already good and dry.  Why..., I don't know?  I'm so used to the humidity here I just didn't think.

I keep all my bows, staves, and arrows in a large gun-cabinet type case that is humidity controlled.  I keep it all at 50%.  I'll go down to 40% for a day or so if things got up to the usual 70+% humidity in the box for days or weeks.  But 50% seems to be the happy place.
I think adding moisture may take longer than removing it.  I would give your stuff a week or more for sure.

[BowEd]

Hate to see that Steve.I'm sure the outside 1/8" just got too dry.
Really what I try to do is keep things within a range.Say 45 to 55 humidity constant,and at a temperature of around 75 degrees.That keeps things in a good range for me of 8 to 9 percent humidity.Which is what these numbers are when I tiller it.I do that at my place by using analog humidity gauges at various places around the house besides by the bow rack.Two dehumidifiers in the lower finished basement that has cement floor and a foam form cement walls.If I had a basement that had completely wooden walls[which makes for a dryer basement] I'm sure it would be dryer yet.Upstairs is air conditioned so lower humidity is there too.
During the winter wood heat alone here shuts the dehumidifies off.Air conditioner too.As would a gas furnace in a basement.A person has to know their dwelling to adjust.
As Mike said once a bow is made and with time kept in these conditions it will be dryer then when first made.Just the way it is.I've read Tim Bakers' findings and believe it to be true that every 1% moisture increases or decreases a bow woods performance by 6%.It can all add up.
The time of adding or decreasing a woods moisture will depend on the woods' density.2 weeks on a finished bow put in an adverse change of humidity is enough time to change things.Roughed out bows a week longer.Staves longer yet.

[DC]

This might be the place to ask this. I live in a humid(70-100%RH) place. I built a warm box with a dogs breakfast of waterbed heaters, humidistats and thermostats. It works well keeping the RH at about 55% but when I put a dampish stave in it tends to swing the humidity all over. I suspect the difference in swing time between the stats messes it up. Anyway, I've been thinking of hooking either an air conditioner or a dehumidifier up to the warm box. I can get a small AC unit for $200 or a dehumidifier for $300. My question is what is the difference between the two? They both use refrigeration to accomplish their goal I assume so why the diff in price and would one suit this situation better than the other. My warm box is only about 15 cubic feet if that makes a difference. I know there's at least one refrig guy on here. help please.

PS Never mind Canadian Tire was clearing it's Garrison 50 pt dehumidifiers Reg $300 on for $135 so I bought one.