How could I have avoided this?

[kelLOGg]

Mold on SYP.. here are the details.
I have been sawing SYP into 2 x 6s and 2 x 10s and stickering them on the customer's trailer. It was dry and breezy and all was going well until stagnant air and 6 days of rain/mist moved in. The lumber never got rained on because I covered it with vinyl siding before the rain but the lack of circulating air is doing a number on it. I thought of adding fans but the trailer is outside. Now we are expecting ~6 more inches of rain in the next week. The only thing I should have done is saw faster but I don't have a production mill so sawing is slow (laugh, emoticons not working).

Bob

[Planman1954]

I could be all wet, but do you think by cleaning off the sawdust with a broom would help? Just a thought...

[YellowHammer]

That's just a turn of bad luck, how man BDFT?  Some guys have posted about spraying with bleach water to clean up moldy pine, but it would mean restacking everything. 
Can you get the trailer under a shed or something to where the fans won't get wet?

[kelLOGg]

I blew sawdust off after some early drying but that didn't get all of it off. It probably would have been better to sweep it clean but I am a one person operation and after stacking 2 x 10s (some  19' 8" long) I didn't care to add sweeping.

I added a tarp to protect the fans from rain and channel the air flow thru the lumber but the humidity had already done the damage. It's cooler and less humidity now but rains are soon to start. If hurricane Jaoquin moves west I will have to weight down the vinyl more.

I have 900 bd ft and 2 more logs to saw. The trailer is 25' long and quite heavy and with lumber on it now I don't think my tractor can pull it to a shed. Anyway, the humidity is high there, too.



 

[slider]

Here in south georgia in the summer months i now use fans until it"s down below 25% on pine which is 60% of what i saw.Last week i sawed some framing lumber and did not use the fans.In 4 days it was molding.Now i factor in the cost of the fans into the cost of the job.
I wish someone would give us a reasonable moisture % that you can stop the fans.I'm thinking humidity plays a big part of that answer.
I have one fan that pulls 12 amps per hr.If i figured it right that's around $4.50 per day.

[GeneWengert-WoodDoc]

Mold is a fungus.  To be active, it requires food (the sugars in the sap, dirt, micro organisms in the air, etc.), moisture (above 22% MC at the surface which is over 95% RH), warmth (warmer than about 55 F, with a doubling of rate of growth for every 20 F warmer), and oxygen.  Eliminate one of these four and you can stop active growth.

So, anything we can do to reduce surface MC will help, including thicker sticks, good air flow, low RH, narrow piles, cooler temperatures or over 133 F.  Fine sawdust on the surface also helps growth (exposes the food), so a clean surface is better.

[drobertson]

I am no wood doctor, but have sawn my fair share of SYP, and have dealt with the same fate.  It could hold just beautiful, then quickly start the molding process.  How to avoid?  The only proven way I have seen(just my experience) saw SYP in the winter months, get it to an adequate air flow and out of the weather under shed. Dry air flow,