Drying 6 x 6 SYP timbers

[Southside]

I have the opportunity to produce a fair amount of 6 x 6 timbers for a new home construction, the subject of drying and HT will be discussed on Wednesday.  Can anyone give me an idea on what sort of schedule / time I would be looking at to dry these in a WM250?  They would be stump green with the exception of any fan time I can get on loads waiting for the kiln to be read to re-load.  Thanks. 

[starmac]

I can't help with the drying time, but there is an outfit up here that makes 7X9 tongue and groove d logs. They cut them 9 X 11 before the kiln and then run them back through the mill before running them through the molder. Originally they did not kiln dry them, but they would twist enough to have trouble with the tongue and grooves if not put in place immediately.

This is white spruce, may not be any trouble at all with pine.

[Don P]

Another can't help with the question but don't forget grading requirements if this is structural material.

[Southside]

Thanks Don,  I verified today that they are non structural and simply for aesthetic purposes. I am hoping someone can chime in here as I do have concerns with pitch bleed if these are not dried.  Perhaps @GeneWengert-WoodDoc  has some insight? 

[GeneWengert-WoodDoc]

If these will be used inside, then we need them drier than if they were used for a deck, etc.  probably target 10% MC.  You also might consider a kerf on the hidden face, as this will concentrate most cracking on this face.  Drying is needed in order to avoid warping in use.  SYP is especially hard to dry without warp.  Incidentally, when sawing, no crooked trees and always center the pith in the middle of the 6x6.   Drying time depends of fans, temperature, humidity and initial MC.  I would say from green with all four sides exposed and slow drying for highest quality that we would be around 40 to 50 days.  A better approach would be to shed fan dry for a month or two and then go into the kiln,

To set the pitch well, I suggest no lower than 160 F.  You might consider a small separate chamber for this heating.  This will also kill any bugs.

I would stack them using dry 2x4 for stickers.

This is a short drying class.  There is more,

[Southside]

might consider a kerf on the hidden face

Thanks Gene.  Any suggestion on the depth and size of the kerf?  Would running them through a shaper with a back relief knife or a groove cutter in it do the trick?

[GeneWengert-WoodDoc]

width can be small, such as 1/8".  depth might be close to halfway.

[scsmith42]

I've dried 6x6 SYP below 25% in my L200.  Takes around 7-8 weeks from green.  

If you have them pressure treated, the core must be below 25%.

[slider]

Scott what would be the cost to run your L200 for 6 weeks ?

[scsmith42]

Depends upon the time of year (cost more in the winter due to heat loss).   With a 24 hour run at the end to set the pitch, you're probably looking at energy costs in the .30 - .40 bd ft range, depending upon how well insulated your kiln is.