Author Topic: I have a question plz... (Read 5016 times)

akila · « **on:** March 19, 2008, 08:37:57 pm »

Hy guys...i just made my self a heat-box for drying a little my staves.....and i want to ask you whatt temperature should i have in the heat box for dring wood....thks in advance....right now i just use 3 bulbs ...each bulb is 40W...and the temperature is 52 degrees celsius( 152 fahrenheit)...do you think it should be hoter then this???

ricktrojanowski · « **Reply #1 on:** March 19, 2008, 08:50:50 pm »

I think that's too hot. I'm drying for a few weeks at 85 F then planning to up it to about 95 F until they stop losing weight. Also it's important to keep an eye on the humidity in the box. I'm trying to keep mine about 40-45% (not sure if this is too high). I don't want the staves to get to brittle. Hopefully someone with more experience can chime in since the hotbox is new to me as well.

Rick

akila · « **Reply #2 on:** March 19, 2008, 09:07:57 pm »

Hmmm..i dont know what to say....i wass not planing on drying realy wet wood.....i have right now some wet wood that i just split in half, and im planing on leaving first to dry a little outside in the open air...and thenn after a month or so to put it in heat box for 2 or 3 days to be sure that its dry enugh to make bows out of him...so this is why i wass asking whatt temperature is the best....you know i have all most 85 degree fah. in my house all the time...

...

JackCrafty · « **Reply #3 on:** March 20, 2008, 12:43:11 am »

Akila....Drying wood is a tricky business. I've heard that 105^oF is the safe upper limit on a heat box. Also, put a small fan in the box to circulate the air. As a general rule, the more dense the wood, the slower it dries (without cracking/warping).

Also....if the air is very humid where you live, it will take several months for the wood to dry enough for you to safely put it in the heat box at 105^oF.

ricktrojanowski · « **Reply #4 on:** March 20, 2008, 12:49:20 am »

I'm starting at 85 just to get things going without really blasting the wood. It's pretty cool but my basement is about 60 with 60% humidity. So 85 and 40% seemed like a safe starting point. Then after a few weeks go to 95. This sounds pretty much like your plan minus the initial lower temp in the box. But I still think 150 F is too high, but like I said I'm just a beginner.

Shaner · « **Reply #5 on:** March 20, 2008, 01:06:58 am »

What wood are you using and how wet it is? Is it the whole stave or roughed out? If you want to dry it out faster you can rough out the bow and seal it all with shellac or something then throw it in the heat box. Somewhere between 95 and 105 has worked for me without getting any cracks.

carpenter374 · « **Reply #6 on:** March 20, 2008, 01:36:02 am »

kiln dried wood is dried at about 150 degrees. try making the stave uniform in thickness and width make sure to seal the ends. strap it to a thicker board if the stave is less than 2 inches thick

akila · « **Reply #7 on:** March 20, 2008, 06:10:03 am »

The wood that i want to dry is wite ash....here in Romania wi have a normal climate...its not verry humid....the wood has a rectangular shape iff i can say that...iits 2" wide and 2" thick....how to you make to be a certain humidity in the heat box????to you have a meter to mesure this humidity thing in the heat box?

Pappy · « **Reply #8 on:** March 20, 2008, 07:15:28 am »

I keep my box at about 90 degrees,it isn't so much the heat as it is the low humidity in the box.I have a couple of holes in the top to let the moisture escape.Now if you are doing a glue up or some kind of lamination you may want more heat,ant sure on that cause I don't do any.If you get it to hot or try and dry it to quick you will probably get checks or twist.Slow and easy. Work it down a little at a time without bending it and put it back in the box for a day or so and then thin a little more.You can dry wet wood pretty fast that way without any ill effects.

Pappy

akila · « **Reply #9 on:** March 20, 2008, 12:20:09 pm »

Hi and i wanna thk. you all for your help....i already did what you all sad to me....i put only 2 bulbs ..40W each...and now the temperatur is arrounde 35 degree celsius( 95 fahrenheit)....i still dont know how to make a certain humidity in the heat box....do you put a bol with water inside your heat box to maintain a certain level of humidity or??? i realy dont know abute this....im thinking that whenn wood is drying , the water that evaporates from the wood, make a resonable humidity inside the heat box.....what do you think???...and i wanted to ask you something els....you guys talk aboute puting a stave for a few weecks inside the heat box....do you keep that heat box running non-stop during all that time??? im thinking that you past pay pretty much electricity becose of that..

...thks again for help

Pappy · « **Reply #10 on:** March 20, 2008, 01:39:28 pm »

No water inside unless you think the wood is to dry.That is what the holes in the top are for to let the water escape.I don't have a humidity meter inside of mine but it will keep it low humidity if you
keep it on.

Pappy

ricktrojanowski · « **Reply #11 on:** March 20, 2008, 11:25:48 pm »

I have a small digital thermometer and humidity meter inside the box. I read it through one of the holes that I put in the box for air circulation. It was cheap about 15 dollars. Also I have a small fan inside the box that helps move the air. You might want to install a dimmer switch on the box in order to regulate the temp easier. I leave mine on all the time when drying wood. It's pretty efficient. I have it lined with 1/2 inch foil face foam, and use 4 40W bulbs. When running at 85 F. I have the bulbs dimmed down so much they are barely on.

akila · « **Reply #12 on:** March 21, 2008, 07:01:58 am »

Hi ..i have a friend that has a hot box made with circulated air and a thermostat...and he is drying wood at 140degree fahrenheit....he use a fromula wich alow him to know exactly how much water can evaporate from the wood in a certain space...that space its completley closed...no holes in the box at all...whenn that space is saturated with water vapor, the water from the wood can no longer evaporated, so in the box is now a certain humidity, and the wood is not drying verry fast...after a wile, he opens the heat-box for a fiew seconds, to allow the water vapor to leave from the box, and now wi have a piece of wood that is with a lower MC....and the proces goes from here and on....the water evaporates again untill the saturated point its reached, he opens the box for a fiew seconds, and so on.....and he can dry verry weet wood withoute checkind or something llike that, in a fiew days(3 or 4 days)...he told me, that the secret is not to allow the water vapor to escape from the box to soon....this way the wood is drying a liitle at a time

Pappy · « **Reply #13 on:** March 21, 2008, 08:28:01 am »

I guess that would work,don't know never done it that way.I keep mine on all the time and anytime I ant working on a bow I keep it there or in front of a stove or in the summer over an AC duct.
Let us know how it dose.

Pappy

Primitive Archer