I've trying my hand at building hickory bows and I understand that moisture content >9% during tillering is the main cause of set in hickory bows. Therefore I'd like to check the moisture content in my stave before I get ahead of myself. Can anyone recommend a meter? I'd go for a used meter if one is available.
Moisture meters on the "interwebs" range in price from around $20 all the way to $300. Usually you get what you pay for, but I'm sure one of you Trad-Bangers has found a gem out there for a lot less than $300. At least I hope so...
I dont have a moisture meter so I cant help you there, I've heard lots of them can be pretty inaccurate. I keep an RH meter in the same place where I'm building bows or storing staves that way I know what the mc of the wood is. Hickory can go as low as 6% mc and still perform great without a tension failure. If you can store your hickory in a room at 70 degrees and around 30-35% rh that'll get you around 6-7% mc.
oh to live in a place where RH was as low as 30-35%...RH in Tampa, FL is 96% right now. My shop is air conditioned, but I doubt I can get RH anywhere close to 30% even with the AC running 24/7. It may not matter, but I'd rather check the wood before spending a bunch of time on a bow that will end up with excessive set. I've tried a cheap moisture meter I picked up from ****-Despot (it reads aroun 13% mc), but I don't trust it. The stave has been in the shop, stripped of bark for 1.5 years...
You don't need a moisture meter to know the M/C of you wood. Do like Okie suggested and purchase a humidity/temp monitor. You can buy them for as little as 6-7 bucks.
Take your stave, reduce to floor tillered, and using your monitor, fine the lowest R/H spot in your house. Store horizonally for a week or two for best results.
Unless you build a drying box you have to go with what you got. Good luck.......Art
If a drying bow is worth it, I'll build one, but it sounds like it isn't necessary...
Thanks for the input.
I bought a small digital kitchen scale at walmart for around $20. I rough out a bow, weigh it, and write the weight on the bow. Every few days/weeks I will weigh it again. Once it stops loosing weight, it is dry. That seems to work for me.
I bought a moisture meter on **** for less than $25 delivered and it works great. When I use hickory for lams I put it in my hotbox on low heat for a week or so before I use it. goes from 9-10 to 6-7.
picked up a humidity monitor from the big-box store. Reads 70% in the shop with the AC on...The moisture meter I have (and don't trust) reads 11-12% on my stave which has been in the shop for 1.5 years. If the RH in the shop is 70% now (our dry season), I feel like I won't be able to get the mc in the stave down without a heat box. Any thoughts on this?
That 70% R/H equates to around 13% M/C. Probably wetter than that in the center of your stave. Like I said, you need to reduce your stave, and using your monitor, find the lowest R/H spot you can find to store it for a good week to ten days. Have you checked around in your house?
Or you can heat treat your limbs as you tiller your bow out. Heat treat before getting to brace height and perhaps again at full draw. Maybe heat treat and tiller several hours later. If your bow takes very little set and feels stiffer than it should then give it some more time before proceeding.
Thanks for the help, Art. RH in the house in 60% with the AC on. The trouble is that it isn't really hot enough right now to justify running the AC. I think I'm going to have to use some heat...
This is all very new to me, so should I rough out the stave to find the bow inside it, then let it sit for a few weeks prior to proceeding with heat and tillering? Or just go for it? Right now the stave is about 2" x 1.5"...
Do you heat as you tiller, prior to tillering, after? I know next to nothing about heat treating....
I never like to go from stave to working bow without some additional drying. If your stave has been standing on it's end then the lower end with have a higher M/C than it's top. I like to rough the bow out and store inside the house horizonally (preferable off the floor) for further drying.
You don't have to heat treat the belly of your bow, but just by heating the belly up prior to any bending you will reduce it's M/C a bit. Got to let things cool completely down before any bending though.
Do a search, plenty of info on heat treating limbs.
Florida humidity and hickory is not a good combination. Even if you can get the bow dry enough to tiller it the mc is going to go back up in the wood over time even if it is sealed really good. You might should try to find some osage or yew to work with.
yeah, I figure I'm eventually going to lose the battle with humidity here, but I'm new at this and I'd like to use wood I can find here since I'm sure I'm going to be breaking a lot of bows as I learn.
I'm in north Fl and I can take a piece of drywood from inside the air conditioned house and in one day in the shop it will be over 12%. I put everything in the hot box for a while before gluing up. But I am doing glass and lams and it is thin enough to dry out quickly. The only self bow I have made that didn't take a set was boo backed ipe.
I have a Mini Ligno and use it throughout the bow making process. Check 3 Rivers. When I get a reading >10% I stop and let the wood dry near some heat. I don't have a drying box. Hickory is best 6-8%. YOu don't absolutely need one but they sure are nice. Jawge
I have a super cheapo I got at Harbor freight. I use it with the knowledge that it is just a guide. It's been a long time since my basement shop has been below 50% RH but better now that I have a wood stove going and I can put them near there for a few days. I really need to move the bow rack upstairs but being married....well ya know.
there is a chart in Trad Bowyers Bible IV....also in instructions given by Murray Gaskins in his Building a Durable White Wood Bow text on his website....uses temperature, relative humidity and the cross gives you the avg MC you can expect in wood that has stabilized a few days.
Buy a RH meter at store or online...keep where you keep your staves and reference the chart. If you cannot get it where you need in the house or shop...will need to build a warming box to remove additional moisture content.
i got a lignomat mini-ligno that Im happy with and seems to be really accurate. I've read all the stuff on RH and time and measuring weight.... but i like being able to see that number just for warm fuzzies.
I have a pinless Wagner, cost a lot but if you are planning to make bows for a long time it is the way to go.
There is no telling how many people have brought me wood that they said was well seasoned and ready to work. One pass with my Wagner told a different story, all the wood was close to green.
Better than a moisture meter is a simple hot box. Keep yourself a back log of staves in the box and you will always have something dry to work on. I have wood and bamboo in my box that has been there for years just waiting on me to turn into a bow.
My box is 12X121X72 and holds 5 or 6 bow blanks. It has three 60W bulbs hooked up to a dimmer switch and will hold 90 degrees with the lights barely glowing. I never burn out a light bulb with them running dimmed all the time. I have adjustable vents in the top and bottom of the box.
Before I insulated it with salvaged foam insulation I had to turn the lights up all the way to maintain 90 degrees. In insulation made a huge difference.
(http://img.photobucket.com/albums/v181/ekrewson/100_0023.jpg) (http://smg.photobucket.com/user/ekrewson/media/100_0023.jpg.html)
(http://img.photobucket.com/albums/v181/ekrewson/drying_box_inside.jpg) (http://smg.photobucket.com/user/ekrewson/media/drying_box_inside.jpg.html)
The one I have is the pin type which really only gives surface readings. I get around that by using it right down to the stave's first stringing. I just stop and let it dry if I get a reading that is too high. Jawge
I'll second what Eric said. I keep them incubating in my drying box at about 90 degrees and keep an old sleeping bag thrown over it for insulation. Voltage reducer turned down in the summer, up just a tad in the winter. Always have stuff ready to work... and finish.
I don't bother with a moisture meter. I just put the wood very close to the ceiling in the garage when its about 12-15%. This is after the wood is sitting outside in a unheated shed for about 8 months.
I usually cut the sealed ends by this time, and I can gauge the wood dryness very close by this method. After a few weeks you should notice some tiny cracks in the ends, that basically tells me its time to work it.
This method has never failed me.
Listen to Art and Eric. With a simple drying box, a low cost humidity meter, and the chart from TBB IV you can get pretty accurate. I think where you're at you won't get hickory too dry to cause a problem. The drier the better for hickory. Since I started following Arts advice I get much better performance on my hickory bows.
Aaron
correct...a warming box with adjustable rheostat...a meat thermometer and a RH gauge (digital) and the chart from TBB is all you need to get very close and as accurate as some of the cheap hand held meters.
Temp then look at RH...and the cross is your MC.
If you keep them inside house it is easier as you can see thermostat on that floor of house. I have my two staves up in my office on rack...RH gauge downstairs near guitar...but a warming box is going to be built again as my last was destroyed when I moved.
YOu can get hickory too dry...for reliability and durability. 8-9% gives you durability and performance...too dry and it becomes brittle...too wet and it is lethargic.
If you cant do the weighing method the temp/rh chart is the next best thing to get accurate MC.