All Replies on Mold on Drying 4/4 Oak

  • Advertise with us
View GLENNpm's profile

Mold on Drying 4/4 Oak

by GLENNpm
posted 01-11-2019 09:25 AM

17 replies so far

View Wildwood's profile


2737 posts in 2640 days

#1 posted 01-11-2019 11:18 AM

If scan this chapter will give you insight why mold & mildew forms on lumber.

Might just take little elbo grease with chlorine bleach to remove what you have there before restacking at new location. If not to deep might be able to mill off any remainder.

Drying rack pictured should work well if sticer your lumber.

-- Bill

View Randy_ATX's profile


881 posts in 2947 days

#2 posted 01-11-2019 11:58 AM

Humidity too high and air movement too low caused the mold. It is salvageable if the conditions are corrected.

-- Randy -- Austin, TX by way of Northwest (Woodville), OH

View fuigb's profile


563 posts in 3463 days

#3 posted 01-11-2019 12:07 PM

Yes to the remarks re: beach for the save and the fan for prevention. Crank that fan! Better yet, reference comments re: DIY drying kilns in your initial thread on the subject of your windfall. Kilns take work and space but the results are superior to air-drying.

One other thing: put weight on your stack or you risk having a twisted and cupped produt.

-- - Crud. Go tell your mother that I need a Band-aid.

View avsmusic1's profile


527 posts in 1190 days

#4 posted 01-11-2019 10:05 PM

is the mold worst where boards were making direct constant contact with the sheet on top? I’m betting a lot of the mold is cause the first 2 weeks it wasn’t getting air circulation. Oak starts crazy wet in my experience and is slow to give it up. My garage was swampy even with a fan for the better part of 3 wks the last time I put freshly sawn WO in it. While you don’t want to rush it cause you’ll get surface checking, once you clean these up air circulation by itself this time or year should be fool proof (read: no heat or dehumidifier). Then just check them more regularly. I use an $8 timer and run the fan on high during the day and let them rest for 8hrs at night – prob overcomplicating it there though lol.

View ArtMann's profile


1433 posts in 1321 days

#5 posted 01-11-2019 10:16 PM

On the other hand . . .

Several years ago, I bought some spalted red oak from a guy and made a DVD rack for my daughter with it. The spalted material was used with some quarter sawn white oak for contrast. The project turned out quite nicely, if I do say so myself.

View tomsteve's profile


963 posts in 1724 days

#6 posted 01-11-2019 11:03 PM

how much of the stack had mold? was it the bottom layer only? its wise- when stacking on concrete- to lay some plastic on the floor before stacking.

View GLENNpm's profile


25 posts in 302 days

#7 posted 01-13-2019 12:44 PM

Thanks again for the advice, everyone! Once again the Lumber Jocks are swooping in to save the day.

@Wildwood – Thank you for the reference material. Check out the stickers I made in my first forum post and let me know if you think those will work. I was concerned with warping and sticker stain. So, I planned them all to the same thickness and cut the grove to help airflow and reduce touching surfaces. I think that’s all good, but wonder the thickness planning cut them down to only 1/2”. Is that enough for proper air flow? I’m hoping to make it enough by including fans and spacing each column a few inches apart.

@Randy_ATX – Right. I didn’t realize it would happen so quickly and though I had enough air flow. Apparently not. I’ve cranked up the fan, added a second one and opened my garage door a couple inches to hopefully help with all that. I’m hoping it’s not too late. I think it will be OK from the feedback I’m getting.

@fuigb - First thing I did, my friend! This is putting me in gear to just do that kiln. I just ordered the stuff to do it this week. By the way, I did seal my ends a while back. Not with anything recommended, but I had some oil based Kilz primer that I’m hoping works better than nothing. So far so good. I’ve got some weight on it as well.

@avsmusic1 - The very top boards that contacted the plywood weren’t molded, surprisingly. But the plywood is, unfortunately. The top middle to top part of the stack seemed to be hit the worst. How much WO did you have in your garage and how did you stack it? did you leave your door or window(s) open? I’m wondering if the lack of fresh air hurt me. The fan might just be moving around wet air.

@ArtMann - Yeah, I’m not so worried about the effects of the mold on the wood aesthetics since my main project for this stuff is for a new large benchtop. I’d like it to look nice, but not necessary. I’m mainly concerned with it being compromised and unusable. Also, I’d like to learn how to do this correctly, so I don’t have these issues again in the future. I plan on doing this a lot more over the course of my life and after this round, I’m going to care about the aesthetics a lot more.

@tomsteve - It’s tough to say. Certainly less than half. The ones affected were pretty bad, but there were several that didn’t have anything on them. But just because I couldn’t see it (yet) doesn’t mean it isn’t there. The boards most visibly affected by the mold were sort of hit or miss. The bottom actually seemed to have less mold if anything. I’m guessing that’s because my box fan was on the floor, giving them better airflow. I’ll definitely lay down some plastic when I restack again this week! I’m assuming that generic Harbor freight blue tarp is good enough or do I need something special?

@everyone -
To wrap things up, here’s what I’m getting from you all and my internet research:
I’m thinking on my next break from work, I’ll scrub the mold off with either alcohol, vinegar, or maybe a bleach-detergent solution (apparently, bleach alone can’t penetrate the pores to completely kill off the mold). I went ahead and ordered a small dehumidifier and moisture meter that should get to me on Tuesday. I’m thinking I’m going to try the simple dry kiln under a sealed tarp with the dehumidifier (and maybe a space heater) someone mentioned to me recently. I’ll closely monitor and do some more research on what settings to use to keep from drying too quickly. In the meantime, I now have 2 fans on high blowing on the stack from about 8 feet away with my garage door cracked open a couple inches. I’m wondering if one of my problems was having the door closed. I had some air movement with the fan before, but no regular source of fresh air to replace the increasingly humid air in the garage.

Thanks a lot for the help again. Hopefully, this will get me on my way to posting projects on here soon instead of just a bunch of questions! Of course, any further input or advice on my plans is always appreciated.

-- Never stop learning.

View Panhandler80's profile


11 posts in 274 days

#8 posted 01-13-2019 02:00 PM

Boy, I’ve got a lot to learn.

If any of you all want some fishing / hunting / banking / HR / insurance / boat / mediocre legal tips please give me a shout. Otherwise I have very little to contribute here.

View Wildwood's profile


2737 posts in 2640 days

#9 posted 01-14-2019 04:39 PM

As long as stickers even thickness and space adequately don’t see a problem. Most references call for sticker thickness of 3/4” to 1” many people just use 1×2’s cannot remember how thick they are.

I have used regular Clorox household bleach on wood to remove mildew and mold on raw wood using one cup of bleach to gallon of water. Let set for awhile and then dried with paper towels. Some directions call for neutralizing with water & baking soda solution but didn’t do that.

Think trying plain old Clorox & cold water what your looking for to remove mildew & mold. If any mold or mildew remain either sand or plan rest off.

There are three different methods to bleach wood for different purposes think for removing mildew & mold Clorox simplest, Oxalic acid and Two part wood bleach & baking soda rinse or vinegar to neutralize will also remove mildew and stains but pretty sure folks looking to lighten color of wood. Just follow directions for last two methods.

-- Bill

View Logboy's profile


75 posts in 3735 days

#10 posted 01-26-2019 04:51 AM

Mold is fine, but fungus is not. The fungus will stain black down into your wood, particularly under your stickers. That’s where sticker stain comes from. It stains into the wood and does NOT plane out. Id relocate your stickers. 16” or even 24” on center is fine.

Drying is controlled by three things: temp, humidity, and airflow. You either need to up the temp, lower the humidity, or increase the airflow. Your wood will stop molding once it gets below 22% moisture.

Heres your air drying info.

Run your box fan during the day and turn it off at night as it wont do anything after the sun goes down and the humidity comes up. If its raining, same thing.

If you have any bare steel woodworking tools in your garage, wax them immediately. The tannins in the oak will be released in the air with the moisture and rust them very quickly. Ask me how I know.

View GLENNpm's profile


25 posts in 302 days

#11 posted 01-26-2019 08:36 AM


Wow, that’s some good information. Thank you. Unfortunately, I haven’t had a chance to do much with it yet. I re-stacked it all in a more convenient area a little higher in order to be more narrow. Spacing should be OK. I have 2 fans blowing on high now as well. As soon as I get a chance I’m going to re-stack them once more while soaking/scrubbing them in vinegar. My research suggested that it does a better job penetrating into the wood to completely kill the mold/fungus than bleach. I’ve got a small space heater and dehumidifier I’m going to put under a tarp with them and recheck moisture content every 12-24 hours. Hopefully it’s not too late. In the meantime, this give me reason to be thankful for not having many nice steel tools yet. lol

-- Never stop learning.

View dannmarks's profile


1005 posts in 1087 days

#12 posted 01-26-2019 02:57 PM

I have been drying green wood most of my life and I am kind of old. But I have always stickered outside for the first year. I just think you are trying to hard. Make yourself a nice flat area with good drainage and leave it outside the first 6 months to a year. After that you can sticker it inside and if you heat your garage while wood working the dry heated air will continue to dry the wood over time to a pretty low moisture content. Some of the wood you see in these pictures have been stored like this for over 30 years. Keep buying green wood and continue to dry it this way and you will have a life long supply. Make damn sure that the shelves you build are over engineered for strength. You do not want this wood to come down. But if you have only a few feet of space it is probably easier to get it right. I had 4 to 5 ft above my selves and I have a lot of weight up there. So mine are seriously over done to support the weight. And setting up a small Kiln is always a good idea. I would still sticker it outside the first year or so. But setting up a small kiln above would be a great way to finish it off.

View Logboy's profile


75 posts in 3735 days

#13 posted 01-26-2019 11:50 PM

I wouldn’t use vinegar as it can affect the final color of the wood if it soaks in. Just mix a gallon of water with a quarter cup of bleach in a cheap pressure sprayer and you’ll be fine. Just make sure the wood gets plenty of airflow and don’t smother it with a tarp or something.

View therealSteveN's profile


3855 posts in 1079 days

#14 posted 01-27-2019 02:31 AM

I wouldn t use vinegar as it can affect the final color of the wood if it soaks in. Just mix a gallon of water with a quarter cup of bleach in a cheap pressure sprayer and you ll be fine. Just make sure the wood gets plenty of airflow and don t smother it with a tarp or something.

- Logboy

^^^^^^^ This.

No cover needed at all inside a garage, it would just shed off water if outside, doesn’t need to touch, just be over, like 12” over if possible. Think airflow, at this stage that is what is helping to dry. Off the ground with cinder blacks and the 2x material crossways to stack on is good. Make the stack with stickers between rows, and boards not touching their neighbors (think picnic table spacing or wider). You haven’t hurt anything yet, just more space, more airflow needed.

-- Think safe, be safe

View Logboy's profile


75 posts in 3735 days

#15 posted 01-27-2019 03:09 AM

Yup. The only time you cover lumber is to shield it from direct sun or rain. If its inside you don’t need a cover. I have thousands of bdft air drying inside a barn with one wall open to the outside. I put concrete blocks on top of the slabs but don’t mess with the lumber. (I have a lot more than you do and can afford to be lazy and have a couple warped boards.)

View pintodeluxe's profile


5981 posts in 3319 days

#16 posted 01-27-2019 03:28 AM

I’m in the air dry outside club. I give stacks of lumber time and exposure to wind but not rain for 10-12 months. Then I haul them into my DH kiln which I ramp up to 100-120 degrees for drying. Four attic fans push air over the stack constantly. Then I go hotter at the end of the cycle to kill any bugs.

I wouldn’t treat the mold with anything. Just wear a respirator when you mill it. Most of the mold and staining I’ve encountered is pretty superficial.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View Logboy's profile


75 posts in 3735 days

#17 posted 01-27-2019 04:38 AM

A couple more things to mention. The mold is more than likely just on the sapwood since that’s the part of the tree that is actively growing and contains the sugars they feed on. I always make sure that boards with sapwood, ESPECIALLY with wane (bark) on them are stacked on the outside of the pile while the heartwood goes in the middle. The sapwood has a higher moisture content anyway, so that way they both get done air drying at the same time. Its funny when pulling boards off the mill because you’ll have a board cut from sapwood that weighs three times more than a board from the heartwood due to all the water in it.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics