wood drying kiln for bowstaves

[jeffhalfrack]

Just  my  two  cents,I'm  a  hvac plumber 32 years   I do  a couple  self bows  a year I can get green wood  boards  easy  what  I  do is  I  have  a  small  closet in  the  basement, and I put a 30 pint  'Dehumidifier' in  the closet it's about  moisture control  i have  dried  wood in there in a  few  weeks   those  units  have some kind of  control on  them and if  you  get  good  air circulation you'll  have  good  results  I  have  lot  to  say  but  this  is  my  job,  and I  do well, and take what you  want  it's  not  rocket  science  good  luck  and  it's  nice to  see  your  thoughts grow JeffW

[sailordad]

i let my wood cure naturally
any staves i get i leave sit for a year atleast,i got a sweet osage from sawfiler a year ago
he said it was seasoned and ready to be worked
i wont start on that one till the end of this month
but i do have a hot box,its made from that foill backed insulation
has 3 125 watt bulbs,each has their own switch,all of which are also controlled by a rheostat(a light dimmer switch)
i can run one ,two or all three bulbs at one time and adjust the rheostat to controll them
i have had that sucker up to 180* f,and that wasnt even with all thre bulbs crancked up all the way
i built it for glue ups,never even tried to dry a piece of wood in it
i took one of my AC thermometers from work and just poked it right thru the side of the box

[animus_divinus]

hot water thermostats allow you to adjust temperature for the most part, and theyre not expensive

i wish there were a variety of thermostats available to the hobby market, but unfortunately it seems central heating, water heater, or applicance thermostats is all we can find

[Timo]

My lowest setting is 90 degrees. I set it there and it will range from 85 to 108.Most of my wood is perty dry before I put it in,so I don't need high temps. ALthough......I have done some serious checking.

I also run a humidity check.20 to 30 % seems to work just fine for my local. Three 100 watt bulbs is plenty of heat.

[animus_divinus]

i have a 3/4 inch sheet of MDF laying around... need to find something useful for it... would this be suitable for a hot box? or is the heat not going to go well with the chemicals used to bind the MDF?.. i know its nasty stuff to inhale if youre cutting it

second, IF i can use MDF, would it be a suitable insulator as well? i ask these questions because this is what i already have

if not, ill just make a frame with construction grade pine, route a lip around the inside of the frame to cut sections of thin plywood for aesthetics, and then line the interior with the foam insulation which im thinking ill attach with double-back tape

one idea, which seems to be a common one is using light fixtures to hold 100w or 125w bulbs... is this the most efficient way to go?, or would using an inexpensive heating coil, perhaps even the screw in type heating coil a hot water heater uses which is inexpensive, and less energy is used to actually convert into light, so more wattage will go into making heat

also what i plan to do is use one of those dial-face thermometers with the stem... drill a hole into the front of the box, press this thermometer in so i can get an accurate reading on the inside of the box without opening it, and these thermometers are like $5

lastly, reading humidity in the air, tells you what the humidity in the air is, the only accurate way to tell how much has actually been removed from the wood is to weigh it before and after, so one idea i had as maybe a future add-on of this box was to mount a pressure-plate inside, to that would be bolted a light sheet of plywood to match the floor of the box... that way when you put your wood in you can take a reading, calculate what it should weigh when its done, then check the weight periodically until it matches that figure

those are my ideas so far.. and i should mention that i have an otherwise fully equipped woodshop that i use for a variety of tasks, a major use is building musical instruments, so having such detailed control over the wood would be worth the little extra cost to do something like add something to the inside to weigh the wood as it dries

[animus_divinus]

check this out

http://www.amazon.com/Pound-Capacity-Digital-Shipping-Scale/dp/B000R4HRGO/ref=sr_1_22?ie=UTF8&qid=1297244060&sr=8-22

imagine having that on the bottom of the box.. 1/4 or maybe even 1/8 inch sheet of plywood bolted to the top and the scale is re-zeroed.. then the remote display can be mounted to the outside front of the box with the wire passing through a small hole... and with a 330lb capacity you could dry and measure a lot of staves

and this is the thermometer i mentioned id use, just drill a hole for the stem to fit into the box and leave it mounted outside

http://www.amazon.com/Taylor-Classic-Instant-Read-Pocket-Thermometer/dp/B00004XSC4/ref=sr_1_11?ie=UTF8&qid=1297244257&sr=8-11

[animus_divinus]

might just be better, and a lot easier to measure the humidity in the box afterall.. when that stops dropping the wood SHOULD be finished.. i guess im just a bit of a perfectionist

[jeffhalfrack]

  A D  now  your  thinking  !!!!! air flow+  low humidity over time= cured wood!  wood will loose it's  moisture at a certain rate, too fast or  hot = checking, .  just  control the humidity above  freezing and you'll  have  good results,  for instance  what  happens to  a  slice of  baloney in  your fridge un  wrapped?  jerky,,,,,  put it in  the  crisper drawer  (where the  air movement is restricted ) it last longer!  I  think you are on to  something!!  keep at it good  job  Jeff W

[Pat B]

The secret to having dry wood is to have a stockpile of wood on hand.    After a year or two all of your wood is dry and in a few more years it is seasoned.
 Wood, left alone will hit an equilibrium with the relative humidity(R/H). The rate(hygroscopic rate) at which wood changes moisture content(M/C) is quite slow. Wood will normally dry at a rate of 1" per year but will stop loosing moisture when it hits that point of equilibrium.
So, once your wood is at equilibrium it is only a few % of M/C that you have to change artificially.  I understand your delima. You are relatively new so you don't have a stash of good bow wood...and you really want to build a bow.
  With whitewoods you can have a stave ready to build a bow in a month or a little more if properly cared for. This time of year in most of the US the R/H is quite low. Any wood you have stored under shelter will be loosing moisture at it's max rate right now because of the naturally low R/H. Actually, under your bed is a very good place to cure bow wood. Just enough air flow and dry inside air surrounding the stave.
  Take the time between now and when your wood is ready to build bows and prep all your staves to floor tiller stage. By the time you have completed your first bow you will have the beginning of a stash of dry bow wood. Try to think more long term when it comes to wood bow building. You can quick dry bow wood in a relatively short time and build a bow with it but once you build a bow with that same wood that is seasoned you will see the difference.

[animus_divinus]

well.. im quite skilled with woodworking, and using a variety of tools to carve, shape, and manipulate wood.. carving bows certainly isnt out of my range.. all my lumber consists of boards that are either carved into instrument necks, glued together for electric instrument bodies, or sliced up and planed for sides and backs of acoustics...

building the box is easy.. regulating it with a thermostat and heating it with bulbs, or even a screw in element is also easy.. just knowing when ive achieved equillibrium is what i need to determine.. and im just not sure if weighing the wood for moisture loss, or measuring the humidity in the box until it stabilizes is the best way to do that

[sailordad]

if you take a stave and tap the ebd of it ona concrete floor and it makes a ringing type sound
its dry
if it make a dull thud type noise
its still wet 

this is actually how i do mine,like i said i let my wood dry/season naturally
hotbox is for glue ups

[Pat B]

I do like Tim. I go by sound and feel. I bought a moisture meter years ago and never used it. I gave it to Justin Snyder so his wood wouldn't get too dry in Utah where he lives. If you build instruments you should be familiar with judging wood by feel and the sound tools make while working. I'm not trying to razz you. It doesn't have to be complicated and IMO shouldn't be complicated.
  You can use a moisture meter to check the M/C of your staves or you can weigh your staves every other day until they quit loosing weight and you are at equalibrium.

[Bevan R.]

if you take a stave and tap the ebd of it ona concrete floor and it makes a ringing type sound
its dry
if it make a dull thud type noise
its still wet 

Is it because I'm still wet that I thud when I bounce on the concrete floor?

[sailordad]

Bevan all i can say to that is
DEPENDS 

[animus_divinus]

ok.. well, i have what i need then.. i wont use the MDF though since that crap tends to bow often, plywood tends to resist it better so ill make it from that

i plan to start learning how to make bows with hand tools, basic ones like a hand axe to give myself even more of a challenge

anyway, i know a guy willing to trade me a custom instrument for a bunch of osage orange branches i can cut into multiple bowstaves, i might take him up on that