Sycamore Drying Schedule
Advice on a drying schedule for Sycamore in a dehumidifier kiln. August 8, 2008
Question
I have in the past air dried quartersawn Sycamore to 25% then put it in the Nyle kiln at a 100% cycle. I had a lot of splitting while the sycamore was air drying. I now want to get some fresh from the mill, and dry with the Nyle. What kiln schedule should I use? The book that came with my Nyle has no schedule. Research in this forum says to dry aggressively. Should I dry like pine? Sycamore sure is soft, and light like pine.
Forum Responses
(Sawing and Drying Forum)
From Gene Wengert, technical advisor Sawing and Drying Forum:
Go to page 58 and look at table 55 for 4/4 through 6/4 Sycamore. Use a lower temperature but the same RH with a DH kiln. This schedule is not like pine.
Kiln Schedules
From contributor B:
I dry 4/4 QS Sycamore on a regular basis in a Nyle 200 / Woodmizer 4000 series DH kiln with excellent results. I have the lowest amount of degrade when the wood is end-sealed as soon as possible after logging and into the kiln within a few days or week or so after logging. Usually my defect rate is less than 1% (including end checking). End sealing as soon as possible after logging and moving quickly from felling to drying are the key reasons why. Per Nyle's recommendation, I use the same Group 3 schedule as for 4/4 oak, which is anything but aggressive. For 8/4 Sycamore I'll air dry it down to 25%, and then use the Group 4 schedule. Usually a full load takes 3 - 4 weeks in the kiln from green.
From Gene Wengert, technical advisor Sawing and Drying Forum:
The Table 55 schedule has an RH setting of D2, which is the same as red oak, so Scott's comments and NYLE's suggestion are both in agreement with Table 55 for a DH kiln.
From contributor C:
Is quartersawn that much more stable than flat sawn? I have dried several thousand feet of flat sawn sycamore and would usually lose 5 to 10 percent to warp and twist. I would make my stacks 8' tall, with about 1 ton of weight on top, and on every load even some of the boards in the bottom rows would twist so badly they would rise up an inch above the sticks. The customer who was buying it finally got tired of trying to work with it. He would plane a bundle of it one afternoon and the next morning a lot of it would be twisted. I got him to start using white ash instead and we were both a lot happier.
Sycamore is the only species I have ever had trouble with. I would dry white ash most of the time with hardly any degrade and I don't even put weight on top of it.
From Gene Wengert, technical advisor Sawing and Drying Forum:
Quartersawn cups less but will twist the same. Quartersawn will also side bend, while flat does not. The tree growth determines the amount of warp.
From contributor B:
I've seen a significant difference between drying QS and FS/RS Sycamore. I much prefer drying QS. I don't weigh it down; hasn't needed it so far. For best results, use only high quality butt logs and apply end sealer as soon as possible after logging - preferably same day.
