Hi Sawmill Forum,
I am a wood novice trying to work out how to properly dry 60 cypress planks that are being supplied as fresh-green lumber. I need the fastest, yet safest, solution as my job is somewhat time sensitive and our workers are ready to make use of the lumber now.
The lumber is for a 108-passenger wood ship from the early 1970's. The hull between the water line and the main deck uses 8 quarter cypress planks that average 16ft long and 5-6 inches high (which I believe sawmills refer to as the width). Sixty of these planks are on their way to us in Southern California.
The sawmill cutting the lumber is not drying it, so I have to find a kiln. Based on my limited research, drying wood (and doing it properly) is a science so I could use some help to make sure I am asking the right questions and finding a capable service to get it done right. This forum is terrific as I've been able to educate myself on some of these questions which are below in bold for those who want to get right to it.
We removed the bad planks already and covered the cavities with plastic, so there is some urgency to get the new boards in place before our rainy season but I do not wish to rush the drying process and end up with warped or cracked planks. Our entire hull is double planked with cypress. It was quite a challenge sourcing it!
I understand the concept of drying is to remove most of the water quickly without destroying the wood. People say to dry them slow but, if a kiln and correct procedures are used, how long should I estimate for this process in our project schedule? And, can it be done in under two weeks or is that unrealistic?
They say to seal the boards to control the drying but what sealer should be used and where is it to be used?
I read the most critical time of the drying process is taking your lumber from green down to 35% moisture content since most of the degrade occurs during this time.
I read that each wood species has an optimum drying rate which, when exceeded, will leave you with a pile of warped or cracked firewood. How do I find the drying rate for bald cypress? Is there a drying schedule or drying recipe for cypress?
I read that certain species, such as pine and cypress, are very difficult to damage in a kiln because they dry so quickly. Is this true?
Do I need to need to buy a moisture meter? I'm in Southern California, FWIW.
Once it's back from the kiln, can we install it right away or do we have to wait for it to equalize with the ambient temperature. If we have to wait, how long? Since this is for a boat upper hull (these planks are not under water) there is some expansion and contraction that takes place. I've been told the wood needs to equalize before we install it or it seems conceivable it could swell up or contract and cause cracks in the paint that top coats it.
What type of Kiln should I be looking for, Conventional (High temperature), Dehumidification or vacuum? Are there any in Southern California?
Do I need to micromanage the service we select to do the drying? i.e., make sure the operator stacks the wood flat and it is weighted down so it doesn’t warp. I respect professionals and prefer to leave them to do what they know but need to balance that with getting this right.
Thank you for answering any or all all of my questions.
Nick Baggs
Marina del Rey, CA