Purchasing kiln-dried lumber
1) I realize there are solar kilns, air kilns, heat kilns, etc. What type of kiln produces the moisture content I want?
2) What is the best way to qualify a lumber source? What questions should I ask before putting in an order?
3) Has lumber grading gotten worse over the last couple years? Seems like I'm getting a lot of sap.
4) Am I asking too much from a supplier?
5) What is the MC standard?
I hope you took your complaint back to the supplier. Unreported complaints (or those reported to someone else) are every supplier's worst nightmare.
To answer your questions:
2) Know what you want, be specific in your order, and "trust, but verify."
3) If lumber grading has gotten worse, it would have failed in its purpose to provide a consistent and repeatable standard that is constant over time. If you are referring to the poorer grade of logs that are now being utilized, you will probably get no argument, but still a #1COM and a FAS should be the same as previously.
4) No, you should demand more, but you must specify what you want.
5) The MC standard is what you specify based on your needs.
Read the "Rules for the Measurement and Inspection of Hardwood and Cypress" from the National Hardwood Lumber Association, paying particular attention to the NHLA Sales Code and Inspection Regulations, or attend a lumber grading short course.
I agree with the above 100% and add the following:
2) What is the best way to qualify a lumber source? Look to see if they are a member of the NHLA and also if they have the NHLA Certified Grader logo (which means they are inspected every month).
4) Am I asking too much from a supplier? Many suppliers would be glad to work with you. What state are you in? Anyone who delivers 10% to 12% MC is not a good mill to deal with, as very few uses require MC this high.
5) What is the MC standard? The NHLA has no indication of the moisture content limits or ranges for KD lumber. It is entirely up to you. If you do not know the correct MC for your use (most often, 6.0 to 7.0% MC and very strict about these limits for the finest furniture), how would the kiln operator?
Gene Wengert, forum technical advisor
Just playing devil's advocate here. What method are you using to measure MC and where on the board are you measuring it? How long are you storing it before you measure the MC and in what kind of conditions are you storing it in?
None of the grading rules that I remember grade against sap or treat it as a defect. You can, however, specify what you want in your order, but be prepared to pay for a special sort or grade. The grading rules are set up to be a base guideline which modifications can be added to. By chance, are you referring to cherry? This seems to be a common complaint in cherry and pertains directly to log size and as such, log size may be bigger in some parts of the country as opposed to others.
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