Moisture meters, addenda 4-14-13

My moisture meter, a Mini-Ligno, from Lignomat. A fairly common, pin type meter, still available as above, and also with a digital readout. 

In the above two pictures, a reading from the face of a recently gessoed frame element, showing 14%. The bottom picture shows a reading from the side, ungessoed at 6%. The wood was at 6% when I started to mill it. I like to be at 6-8% at the start. A pin type meter does leave pin holes, but they are easily filled, and there are always parts of a frame where the holes do not matter. For my purposes, this meter is more than accurate enough. 

I think having the wood at a low level to begin reduces cracking at the miters. Patience helps, in waiting for the frames to properly dry after gesso is applied, because any cracking can be filled before the finish is applied.

Addenda: I've owned both pin and pinless meters, and there are pros and cons to both. Since I like to read the wood before I start milling, a pin meter works better. The roughness of the wood can lead to poor readings with the pinless meter. The large sensor pad also makes it very difficult to do the kind of reading I'm doing on the gessoed frame in the top photo just above. Pinless meters tend to be more expensive, and also require some skill in their use. But, they will allow for a quick reading of a whole board, to see if it's consistent. ( This can be done with a pin meter; it just takes longer, and leaves a lot of holes. ) They also penetrate more than the small pins on the Lignomat above, though larger pins can be substituted. The unit above comes with two sets of different length pins, though MC will be read from the highest MC. To get core lumber readings, long, insulated pins are needed. I'm not concerned about core readings, as the lumber I'm using has been stored in a sheltered space, and is probably pretty consistent through out after it has had some time to acclimate. 

Or, one could take the Steinway piano approach. They store lumber in an open yard for quite some time, before being brought inside to acclimate again. The idea is that by the time the lumber is brought in, it will have done all the warping, woofing ( see here ) cupping, checking, shrinking, splitting, and what's left will be good, well behaved lumber. We don't need no stinkin moisture meter!