Drying thick oak slabs

[D6c]

I've got several burr oak slabs that were cut two years ago and have been air drying.  They're 3-4' wide by 13' long and 2½-3" thick.
A few days ago I put them in my solar kiln and closed the vents close to shut.

We're going into winter (Iowa) and was wondering if they'll dry very well in cold weather.
How much above outside temp should I set the fans to come on?

It's not real practical to cut kiln samples to check moisture so it's a guessing game.
Should I just leave it all winter and hope it dries?

[GeneWengert-WoodDoc]

We are a month away from the shortest day of the year, the winter solstice.  Until we get more sunshine and temperatures over 50 F, drying will be slow.  The fans should come on when the dryer is about 25 F hotter than outside.  It is a suggestion based on both efficiency and cost.

A pin type moisture meter will help you get an average MC and the core MC.  Expect to spend $250 or more for a good, made-in-USA meter.  You can use nails to get the average  and core values.  Measure only in the afternoon, as the high humidity in the morning will give you a small error.

[D6c]

I have a Delmhorst meter and could get the slide hammer attachment for it but don't want to poke a lot of holes in these slabs checking moisture.

When you say use nails, can I set pairs of fin nails ¼ way and ½ way through for ave and core moisture and leave them for periodic checks?  Any need to insulate the sides of the nails?

[firefighter ontheside]

I just bought the slide hammer for my J2000.  Like you I don't want to make big holes everywhere.  The idea is to use the same pieces every time to measure.  These can placed  around the kiln so as to be representative of all the slabs.  If you plan well, these should be lower quality slabs to avoid damaging high value slabs.  I did not plan well, so I am trying to limit where and when I check moisture and keep using the same slabs.

[doc henderson]

might as well put them in the kiln if nothing else is going to be in there.  keeps out of the rain.  nice and slow after air dry prob. not a bad idea.  would need to vent if the inside Kiln RH (EMC) inside the kiln is getting high.  It will be better than just air drying for sure.  will these be inside a heated space when finished or is that depending on who gets them?  as long as you keep the inside kiln RH lower than outside, I think you are moving in the right direction.  might only be as fast as putting them in your shop, but they are out of your way.

[D6c]

might as well put them in the kiln if nothing else is going to be in there.  keeps out of the rain.  nice and slow after air dry prob. not a bad idea.  would need to vent if the inside Kiln RH (EMC) inside the kiln is getting high.  It will be better than just air drying for sure.  will these be inside a heated space when finished or is that depending on who gets them?  as long as you keep the inside kiln RH lower than outside, I think you are moving in the right direction.  might only be as fast as putting them in your shop, but they are out of your way.

I've got the vents maybe 10% open.  Not sure how they'll end up being used but likely some will be inside use.  Don't have a good way to check relative humidity.  I'll admit I need to learn more about how to read RH and what equipment would work for me.

[doc henderson]

you can get a temp and humidity monitor for 14 to 20 bucks.  



 

relatively cheap and accurite.  my remote is in a container a hundred feet from my shop.  i have put these in plastic wrapped sticker wood as a makeshift kiln.  based on relative humidity, you predict the final MC of your wood, referred to as the EMC.  read the hardwood drying handbook available online for down load and or watch the free webinars on the NHLA website.  all done or contributed to by @GeneWengert-WoodDoc .  for the webinars, you have to register, but not join.  all data including your name must have no spaces.  These units are batt. operated and at least give you an idea.  my shop and my unheated container run about the same.  if the container goes up, I run a dehumidifier for a night to remove water.

[doc henderson]

i have used a dozen or so over 10 years, and get them at Walmart or on amazon.  beer cooler to kiln/container.  i use the container to keep my dry wood at 7%.  for my container, the one I am using, will also show the 24 hour high and low for all number.  you get a reading in the location of the base unit, and the remote (kiln).