Q: I'm getting frustrated with many of our suppliers who are not being held accountable for proper moisture. There always seems to be some excuse for not doing it right. It's not that I want to lower the MC, I want them to be accountable, so we don't get 9 percent MC and higher. Would you look at our specification concerning MC and tell me if it is achievable? I feel strongly about this.
A: It would be easy for almost every kiln-drying operation to meet your specifications, if they wanted to. (I have deleted the actual MC values, as it is possible to achieve whatever MC values a manufacturer desires.) All it takes is good sampling in the drying operation and proper equalization in the kiln before the lumber is unloaded. In fact, I challenge companies that I consult with, whether they dry the lumber themselves or purchase KD lumber, to obtain one load that is dried correctly (that is, perfectly) and to within narrow MC specs. Then process this wood and see just how good manufacturing will be. In fact, some do this and report that they can no longer go back to the way things were now that they themselves know the benefit of excellent MC.
It may take an extra day or two in the kiln (unless they are a really bad outfit and then it may take longer) that will cost $50 per MBF maximum. However, if drying is not done well, then you will pay for it in the number of rejects. So, either way you pay, but I believe it is cheaper to pay the supplier than to pay for defects in manufacturing. In one case, a company that eliminated the wet pieces from production using an in-line moisture meter (when the supplier would not dry better) saw their rejects in the wintertime go from over 300 to just 3.
I do know of several companies that target 6.7 percent average MC. They also regularly achieve approximately 0.6 standard deviation maximum, sometimes less; this standard deviation means that there is little variation between the wettest and driest pieces. Quality is high and rejects are few. In another case I was involved in, the damage (it was carefully documented) from using lumber with a slightly high MC resulted in a $3 million settlement from the supplier - some people are speaking up with a loud voice.
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