Woodworking/Lumber Question

[StealthGTI]

"Anything Goes?" Okay, here's an odd question:

I have these pressure-treated yellow pine deck boards. They're 5/4x6" and have a slight warp to them...

They were a tad worse when they were still damp from the store. It's been a while since I last worked with getting bends out of wood. What works? I'm trying to recall if adding moisture to the concave side (top, in this case) will compel the wood to suck upward as it dries. But I may have that all wrong. The wood is currently bolted to my roof rack and getting a sprinkling rain today. It will be dry all week starting tomorrow. Before this rain, the wood moisture was at about 20%. I plan to stain it black when the moisture is below 14%.

I appreciate any tips for getting this straightened, even though it only needs a little. For the record, this is actually three boards that are connected by glued/screwed cross members...

Thanks!

Scott

 

[PRRGG1]

I'm not sure there's a way to successfully reverse the warp Scott, unless you use a jointer or planer and thin them down as you go. You could sticker them for a few more months and see if things change. Southern Yellow Pine is stout stuff, produced for deck boards, not precision carpentry. Looking at your top photo, it looks like you chose well when you made your purchase.

 

[StealthGTI]

Thanks! The boards got good and wet last night, especially on top. I was optimistic when I laid my level across around noon and saw that they were perfectly flat. Hours later, presumably after drying more, the boards were back to where they were in the top photo. I can live with that so long as they don't get worse. I was hoping to get them straight before I seal them. I may replace then with a single 18x40-inch sheet of 3/4" HPDE this summer. Then paint, rot, and bowing shouldn't be so much of a concern. BTW, here's their purpose, if you didn't see my photo in another thread:

Yes, KOOKY, I know!

 

[Maiden69]

They will last for a while, but exposure to sun-water-temp change will make them warp. If you can get some phenolic boards locally, they are much better for what you are doing. Best option would be a sheet of 1/4" aluminum, but I don't know how that will affect your reception. What I have seen done in the marine industry is the use of marine grade plywood encapsulated in fiberglass. Similar to the video below, but made to your specs. You can drill the board oversized and then fill over the holes with fiberglass resin/chopped matt and re-drill the holes so you don't introduce water to the plywood inside. I have had some success drilling and tapping the fiberglass plugs with helicoils.