wood moisture meter

[joachimM]

Hi folks,
I'm thinking of buying a wood moisture meter. One of the reasons is that I want to check if heat-treated bellies indeed retain less moisture than normal bellies for the same ambient moisture levels. Next, wood data (wood database and so) are typically given for wood at 12% MC. Which may not be that useful for a bowyer's applications.
Also there's a huge variety of meters, going from a few tens of dollars/euros/pounds to a few hundreds. Those with pins tend to be cheaper, but the cheapest ones don't have their pins fixed safely to the meter.
Next, for bow wood, I don't know how deep you should be able to insert your pins. We don't want to damage the bows either by inserting pins 5 mm into the wood...
I don't want to go all DIY either (e.g., https://woodgears.ca/lumber/moisture_meter.html) but would like to get some advice nonetheless.

thanks
Joachim

[Del the cat]

I don't think much of 'em myself, hard to get accurate consistent results, and if you don't push in 5mm you are just measuring the surface and who knows what it's like in the middle?
I bought a cheap one ages ago and have maybe used it 3 or 4 times to see if a broken bow was too dry or to see if a log which I hadn't written a date on was fresh or seasoned.
I wouldn't spend a lot on one as I can't see how they can possibly be accurate.
There's an old saying up North...
"You don't fatten a pig by weighing it" 
Del

[Eric Krewson]

I have had this pinless Wagner since my early days of bow making. I only use it to confirm the wood I am starting to make a bow with is seasoned correctly. Sometimes that "well seasoned " bow wood people give you is anything but.

I know well seasoned osage will register at 12% on my meter in the area I live in so that is about I all I look for. I don't use the different species wood charts. I have also found if I put wood in my drying box with a M/C higher than 16% it is prone to checking. My moisture meter lets me know when wood is safe to go in the box.



These older meters come up on eBay off and on at pretty cheap prices

[nclonghunter]

If you cut green wood yourself, could you weigh it and write the weight and date on it. After a while weigh it again and see what it weighs. Is there a formula that would give you the moisture content or maybe a certain percentage that would give an indicator of its moisture. Just as a example if it weighed 40 pounds (stave) when cut and you weigh it a year later and it weighs 20 pounds, then that is 50% moisture loss. Rather than just dating wood when cut, weighing may be of more value later on...

What percent of weight loss would be needed to make a wood safe or usable for a bow? Is that what a moisture meter is telling you when it reads 10% moisture, it has lost 90% of its weight?

Is this something that is already being done or is useless to try?

[DC]

Do a search on  "Wood Equilibrium Moisture Content Table And Calculator"

I keep about 10 roughed in staves in my warm box(40-50%RH). I weigh them every now and then and write the weight on the stave. When the weight hasn't changed for a couple of weeks I'm good to go. If you don't have a controlled environment to keep them in be mindful of the outside RH. Some times the wood can still be loosing water but if the outside RH is rising the weight will stay the same. The weight of a dry stave will follow the RH. If the RH goes up so will the weight. It sounds like a lot of fuss but it's not really. The end result is a bow that takes way less set and doesn't confuse the heck out of you when you're tillering. If in doubt wait a week, at least.

PS Remember that your local climate(average RH) will be different that lots of other people. What works for drying wood where I live (Vancouver Island) would totally destroy a piece of wood in Arizona

[joachimM]

Do a search on  "Wood Equilibrium Moisture Content Table And Calculator"

Well that's what I usually do. I have a moisture meter where I keep my staves. I have always so many staves drying that they always end up at equilibrium moisture content when I'm ready to work on them. From this calculator http://www.csgnetwork.com/emctablecalc.html I then deduce at what MC my staves and bows are. But when heat-treating bellies, the idea is that heat treatment makes the wood less hygroscopic, as a result the equilibrium MC of heat treated wood is lower at the belly (therefore stronger in compression), and still normal at the back. I want to know how low, and how this depends on how strongly I heat-treated the wood. Can't use the calculator for this.

[DC]

Sorry Joachim, I got from your post that you were just starting on the whole RH and MC journey. You obviously have a good understanding of the whole thing.
So now I get to ask you a question. What are you going to do with this information once you get it? It seems to me that heat treating will vary considerably along the bow, so you wouldn't be able to get solid data no matter how much you spend on a moisture meter.
Unless it's just curiosity, then go for it

[Zuma]

This is a non expert opinion 
Cheap and easy, is the Cheek test 
Unless you are going to use your medium under,
other than ambient moisture content.
Touching your wood , leather ceramics etc.
to your cheek has worked for milennia.
If it feels cool or cold, it's more moist than 18 percent.
Zuma

[Eric Krewson]

I have found the same thing just by holding wood in my hand, if it feels slightly cold I know it isn't dry.

[joachimM]

What are you going to do with this information once you get it? It seems to me that heat treating will vary considerably along the bow, so you wouldn't be able to get solid data no matter how much you spend on a moisture meter.
Unless it's just curiosity, then go for it

I would first start on wood slats and compare equilibrium MC before and after various degrees of toasting. Indeed, to satisfy my curiosity, but also to get in the end a better understanding of the properties of heat-treated wood and how to transfer this knowledge to my bow making. I'm the kind of guy who wants to to know why some things work and others don't.

Will it change anything to how we heat-treat wood? Most likely not. So yes, it's definitely curiosity

[DC]

I understand, I'm a knowledge for knowledge sake type myself. Have fun with it

[Zuma]

Physics is the best because it's real simple. Up, down, hot,cold and a spinning planet.
Learning and applying the principals is endless and rewarding. Thanks for the info. Please
keep us posted about what you learn.
Zuma