Replies

1. 
   LeeGrinding1 | Feb 27, 2003 08:39pm | #1

   Call them, tell them it's case hardened. Tell them you want to return the lumber and see what they say. If you need a test to positively determine if it's case hardened let me know.

   Call them.

   Lee

   Lee Grindinger

   Furniture Carver

1. 
   ESPEE | Feb 28, 2003 07:33am | #2

   What is case hardened? I have heard the term tension wood and this is what it sounds like to me. But the Term case hardened is a new one to me.

   Can you explain the case hardened characteristics on materials in more detail using this term.  It's for my own FYI in the future.

   Thanks Tony

1. 
   StanleyNiemiec | Feb 28, 2003 08:32am | #3

   There was a discussion in January entitled "Characteristics of Wood"  #9995 that you should probably read.  Case hardening and reverse case hardening were discussed therein.

   As to your ability to return the material, it may depend entirely on the terms and conditions of your contract with the vendor.  If the contract is vague and does not include issues like MC, grade and right of re-inspection, they may take the position that they have provided you with appropriate material.  Caveat emptor! 

   You have to recognize that case hardening results from failure to condition at the end of the kiln drying cycle.  It is a drying defect but whether you will be able to obtain satisfaction is entirely up to the terms of your contract or whim of the vendor.

   There is a list of important purchase considerations that should be included with each and every acquistion of lumber.  I have been trying to get this list published in FWW but so far, no go.

1. 
   BOBABEUI | Feb 28, 2003 09:09pm | #9

   Where can I read the article that you outlined?

2. 
   riverr1 | Mar 02, 2003 06:49pm | #11

   Niemeic1,

   Could you post those conditions here please? I'll be driving a couple of hundred miles this week for a substantial purchase, and I sure would like to CMA. Thanks.

   Don

2. 
   LeeGrinding1 | Feb 28, 2003 07:46pm | #5

   Like Stanley said, Zoo, case hardening is a defect caused in the drying process. The nutshell version is this. As wood dries it shrinks. The outside of a board shrinks first because it dries first. The center of the board is fat because it is wetter than the outside. As the outside shrinks it stretches around this fat core and this stretching creates tension. The inside of the board shrinks but because the moisture is now low the tension in the outer shell remains.

   Every piece of wood that goes through a regular kiln drying process is case hardened. The key is a step in the final stages of a kiln schedule called conditioning which relieves case hardening. Lumber is typically dried to slightly below the target moisture content, then it's conditioned. Conditioning entails shooting steam and heat into the chamber to allow the wood to relax. Wood is thermoplastic so with enough heat and moisture the tissue can realign itself as the lignin is softened. The lignin softens, the fibers realign and everyone is happy.

   There are problems with this process even though it looks great on paper but that's it in a nutshell.

   Lee Lee Grindinger

   Furniture Carver

1. 
   fdampier5 | Feb 28, 2003 08:03pm | #6

   jeez Lee,

     do you think that would work for me?  I could just take all my lumber back to the sawmill and start over?

     Actually can't he retreat the wood?  I've always been able to steam case hardened wood for a couple of weeks and then redry it.  But come to think of it,  I've only done it in the middle of the summer when everything is real humid anyway so maybe during the winter heating season it won't workk.

     justa thought.

1. 
   LeeGrinding1 | Mar 02, 2003 06:41pm | #10

   Sure Frenchy, he could condition the wood if he has a chamber he can raise to 180 degrees and inject steam while controlling the humidity completely. Then cool the load down as the equalization step occurs. That's what it takes to condition wood.

   LeeLee Grindinger

   Furniture Carver

2. 
   BOBABEUI | Feb 28, 2003 09:02pm | #7

   Lee,

   Thanks for your response to my question.

   Out of curiosity how do you definitely test for case hardening?

1. 
   LeeGrinding1 | Mar 02, 2003 06:56pm | #12

   The standard test for case hardening is this. Cut an inch from the end of a typical board. With the end grain pointing up cut out the center so you make a fork, use a bandsaw for this. If the tines close it's case hardened. To what degree they close will tell you what degree the wood is case hardened. If the tines spread you have reverse case hardened lumber which is spelled f-i-r-e-w-o-o-d. There is no cure for reverse case hardened lumber.Remember, you're looking at the end grain, these samples are cut from the end of a board.View ImageLee

   Lee Grindinger

   Furniture Carver

1. 
   BOBABEUI | Mar 03, 2003 12:44am | #13

   Lee,

   Thank you..

   Bob

2. 
   StanleyNiemiec | Mar 04, 2003 03:01am | #14

   It is not a good idea to do any testing of boards (especially relating to drying) from end pieces.  Because of the extreme difference of longitudinal permeability, board ends dry first and fastest. 

   Test samples should be taken from sections at least 18" (ca 46 cm) from the ends to obtain accurate results.

2. 
   notDusty | Feb 28, 2003 09:06am | #4

             I would contact the supplier you bought the stock from and tell them the problems you are encountering . Perhaps they will exchange the stock or credit you for other projects . But if you seriously can't use the wood they need to know . While it is true buyer be ware in general . Unless you got the wood dirt cheap after being informed of the problems that exist , you should always have a resonable expectation of being able to use the wood . It may work for a deck , but that is not resonable . Try to exchange it or get a refund . If you have not altered the unused portion in any way , a reputable business will work with you , just be business like and descibe the problems you are experiencing.I have returned lumber a number of times for various reasons . When you have an account and owe them money you have more leverage .

             good luck             Dusty

1. 
   BOBABEUI | Feb 28, 2003 09:06pm | #8

   Dusty,

   Thanks for you response to my question. The FAS 5/4 walnut lumber (rough sawn) that I purchased was $4.25 a bf, what I believe a fair price but no raging bargain.

   One again thanks for the advise..

   Edited 2/28/2003 1:13:38 PM ET by BOBABEUI