Author Topic: Advice for drying 1 inch fir boards  (Read 1319 times)

Offline jesse capp

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Advice for drying 1 inch fir boards
« on: January 25, 2018, 03:13:17 PM »
Hey all,
Not sure if this is the forum to post this but here we go.......

Typically we only dry Spruce and Pine boards. Everything is 1"........ We have been faced with a new task of drying fir boards now and I am looking for some advice/input.

Product is 1x4/1x6/1x8 fir boards for flooring. We want to reach an end result of 10 %MC.
We also need to set the pitch.

We run 5 conventional Kilns and 16 Dehumidifiers.

Any advice on building the schedules and which kilns I should use would be great..


Thanks in advance for any help.

Jesse

Offline MichaelM

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Re: Advice for drying 1 inch fir boards
« Reply #1 on: January 27, 2018, 02:48:26 PM »
Jesse,
The fir (I am assuming Abies, not Doug) will take longer than pine and you will have more moisture variability at the end.  I suggest equalizing at a 25F depression before conditioning or pulling the load to reduce over dry and reduce wets. 

The DH kilns are unlikely to get hot enough h for pitch set.

I suggest not mixing 4" and 8".  Dry the 8" gently to avoid many end splits.

Mike M

Offline MichaelM

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Re: Advice for drying 1 inch fir boards
« Reply #2 on: January 27, 2018, 03:03:45 PM »
Jesse,
It occurred to me - do you need the pitch set for fir.  The true firs, such as white, balsam, etc do not have normal resin canals and have only resin in the cell walls.  Pine and spruce do have normal resin canals.  Without resin canals, pitch is usually not an issue.
All species of softwood can have traumatic resin canals if the tree suffered an injury, but these are not common.  Also pitch pockets could occur but the pitch in pockets rarely sets during drying for any species.
Mike

Offline ingo wallocha

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Re: Advice for drying 1 inch fir boards
« Reply #3 on: January 31, 2018, 03:51:34 PM »
Hi Jesse,

We usually dry fir very fast. Sometimes just as fast as spruce or pine. However, we heat it up in a very humid almost saturated steam environment. When the lumber is hot we start drying it to fiber saturation as fast as possible and give it plenty of time to equalize during the rest of the process. We do this in our batch kilns and in our continuous kilns. 

Offline jesse capp

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Re: Advice for drying 1 inch fir boards
« Reply #4 on: February 05, 2018, 09:48:52 PM »
Thanks for the replies guys........

That was kind of our thoughts too Ingo, we were going to use our standard spruce/pine schedule but crank up the temp in the steam step to set the pitch.

Mike - you suggest a depression of 25 degrees before the steam/conditioning step?

It is Douglas Fir we will be drying.

Cheers,

Offline MichaelM

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Re: Advice for drying 1 inch fir boards
« Reply #5 on: February 06, 2018, 05:59:59 AM »
Sorry, with spruce and pine, I assumed you were drying white fir.  You can ignore my comments. Douglas-fir will be far easier.
Send a pm to my osu email with your schedule.  Schedules vary a lot regionally and with desired product quality.  I could ,ake better comments if I knew what "crank up the temp" means.

Offline ingo wallocha

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Re: Advice for drying 1 inch fir boards
« Reply #6 on: February 06, 2018, 02:51:18 PM »
hi Jesse,

But be sure to heat up the lumber with saturated steam, not super heated steam!

/Ingo

 


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