Question(s) about wood moisture levels

[WaltE99]

Hey guys, I'm relatively new and need to know how everyone determines if their wood is dry enough to use or stabilize. I was just looking at a knife I finished up maybe a month ago and noticed the handle appears to have shrunk enough to feel the sharp edge of the tang. Instead of purchasing scales, I bought some wood from a woodworking store that was said to be kiln dried. About a foot each of 8/4 Bubinga and Padauk. So obviouly I should have dried the wood a bit more.

Question 1: How do you determine if the wood is dry enough to use or go to stabilization? I did a search and found a thread in which moisture meters were being discussed and I think Stacy said that they are pretty accurate in the middle of their ranges but not so much at the extremes. Since they typically range from about 5% to in the 40's and we should be looking for around 6% - 7%, it seems to me that moisture meters would not be accurate enough. Maybe Stacy was only talking about the lower priced ones, but if I'm going to plunk down a $100 - $125 for a mid-priced meter, I want to know it's going to be useful.

Question 2: Would using a food dehydrator be a good way to further dry out some scales or blocks?

Thanks!

 

[i4Marc]

One way to avoid the issue would be to purchase wood that has already been dried and stabilized. There are various places to get stabilized woods. If you want to stabilize your own wood you can do a search for "Cactus Juice" but be prepared for the arguments against that. If you're going to dry your own wood and send it out for stabilization it can take quite a bit of time. Most people build a drying cabinet which is just a locker or cabinet with a light bulb or two in it to provide a gentle heat. The top of the cabinet will have air holes to allow the moist heated air current to rise and escape. The cabinet doors do not need to be air tight. Do a search for descriptions and designs. K&G requires the wood to be below 8˚ MC for stabilizing. To determine the moisture content you will need a moisture meter. There are various types at various price levels. There are pin type meters that require you to penetrate the wood surface with the pins. This obviously will leave pin holes all over your wood and they only read to a certain depth. But they are fairly inexpensive. I cannot speak to the effectiveness of those types of meters because I have never tried them. The other type of meter uses a proprietary method of scanning all the way through the wood to determine the moisture content. This only requires contact with the surface of the wood and does not damage the wood in any way or leave any marks. These types of meters can be very expensive. I have the Wagner MMC220 model and it seems to be very accurate as well as being able to dial in the specific gravities for different species of woods. This meter currently lists for $400. If you are going to dry your own wood be careful not to dry it too fast with ovens or dehumidifiers etc. as you can end up with warping or cracking. I have some woods in my drying cabinet that have taken more than a year to drop to below 8˚ MC. It takes time and patience.

 

[Randydb]

If you are after a reasonably accurate pin meter the Phone Works Ryobi moisture meter. Works with your smart phone, and when we tested it with a higher end meter it was always within 1.5%. I think it was $30.

Remember that moisture content is relative too. I live on the coast just north of Seattle. We would have a hard time getting the moisture content below 11%. Move to the prairies and 7% is possible. There are charts that you can get that let you know what is dry for your area.

Wood that isn't stabilized will always move. Likely you put the scales on when it was more humid out and then the humidity dropped and the wood shrunk a bit. I have a knife that I did with unstabilized buckeye burl. It moves every time we get the same weather for four days.
I have sent wood to Kand G twice to be stabilized and it was around 11% both times. I told them but they didn't say anything if they did anything to it.
14Marc is right about drying too fast and cracking. A lot of people rough cut their wood and then put wax or paint on the ends to make it dry more evenly and be less likely to crack. The rule of thumb for air dried slab lumber is 1 year per inch of thickness. Not sure if it the same for smaller pieces. like scales.

 

[WaltE99]

Thanks guys. So if meters are accurate enough to use, pin or pinless?

 

[i4Marc]

I would think it depends on your budget and whether or not you like holes on your wood.

 

[Greenberg Woods]

Hmm. The thing is, woods like paduak and bubinga are pretty stable in general. If they were kiln dried they shouldnt have had much movement, and while some people stabilize bubinga i have never had the need, and i know paduak is not "ambonya is in the paduak family"

 

[WaltE99]

Hmm. The thing is, woods like paduak and bubinga are pretty stable in general. If they were kiln dried they shouldnt have had much movement, and while some people stabilize bubinga i have never had the need, and i know paduak is not "ambonya is in the paduak family"

Actually these 2 knives were a Bubinga and a Redheart. The Bubinga seems a bit worse. The piece of Redheart was a smaller pre-cut piece that was waxed on the ends. Not sure if it was kiln dried.

I have been keeping the knives in my truck and we have had a very mild winter here in eastern South Carolina until very recently when it got pretty cold and, of course, dry. Typically the humidity here is very high. Could the humidity change be the case as Randy suggested? Temperature? I have brought them into house and going to watch them over a few days.

Do you have a meter suggestion without spending $400?

Thanks!

Hmm. The thing is, woods like paduak and bubinga are pretty stable in general. If they were kiln dried they shouldnt have had much movement, and while some people stabilize bubinga i have never had the need, and i know paduak is not "ambonya is in the paduak family"

 

[WaltE99]

Actually these 2 knives were a Bubinga and a Redheart. The Bubinga seems a bit worse. The piece of Redheart was a smaller pre-cut piece that was waxed on the ends. Not sure if it was kiln dried.

I have been keeping the knives in my truck and we have had a very mild winter here in eastern South Carolina until very recently when it got pretty cold and, of course, dry. Typically the humidity here is very high. Could the humidity change be the case as Randy suggested? Temperature? I have brought them into house and going to watch them over a few days.

Do you have a meter suggestion without spending $400?

Thanks!

Oops, a Bubinga and a Bloodwood, not Redheart. Don't know what I was thinking. The Bubinga handled knife is a bit worse than the Bloodwood. Bubinga wood was kiln dried and I'm not sure about the Bloodwood.

 

[J. Hoffman]

I have a Lignomat scanner SD. I bought it on the web for $200. It's been a good meter but I would get a Wagner next time. My guy that does my kiln drying uses a pin meter and swears it's the most accurate.

Any wood is going to move somewhat, even stabilized. I have several knives that had tangs flush with the wood and 6 months later the tang is proud. I know the steel didn't grow