I took the old boards off and the BOTTOM of the boards looks half way decent. I had painted the TOP with used oil 3-4 times in the past 6 years... Thats when we bought it and the deck was VERY DRY - CRACKING..

I painted the NEW 2 x 8 on one face and both sides laying in the driveway. My plan was to install that side DOWN, then paint the TOP with the used oil after installed... Now im wondering if the BOTTOM should be painted ?  Bottom of 20 year old boards looked pretty good.. Maybe the BOTTOM should be open so it can BREATH ?  Wonder if i should just install now with the OILED side UP ?  .....

anyone else notice the BOTTOM of their trailer boards compared to the TOP ??

btms are always better since the sun don't get to them....

oil ALL 6 sides,x3 on the ends !, redo every 5 years

Loose laid boards with the worst one shown with clamp setting but no pressure applied:

Same with clamp tight and just starting to deform the edge from the applied pressure. Second clamp, (Pony) is applying downward pressure removing "twist":

Porto power shoving on the other end to align it. Again the pressure is just enough to start to crush the boad edge:

Allowed to dwell for just over an hour and gave the clamp and porto power some additional force as board is relaxing:

Going to allow an overnight set and will see the results tomorrow morning. There is one more board shown here that is minor but is twisting. This will remove easily:

I have a trough out back I can stack lumber in and fill this with used engine oil. I may do that later when the boards have dried out. I'm putting this deck down with semi trailer decking screws and they both install and remove easily. Hopefully have this task wrapped on Monday as have a small excavator to bring in for service. 

Ran out just before dark and gave the clamps another twist, and the porto power another tensioning. The boards are now all shoved together tightly. I'll let this go till morning and then hopefully they will be close enough to do as you stated and force them together while fastening down.

This trailer has a strip of steel welded to the bulkhead at the front but nothing at the rear except the edge of the 6" channel that is the closing panel. Prior to my ownership 23 years ago somebody bent this channel and I've got to straighten it before the deck boads will fit in the area. I cut all of them even and will use the skid steer and hydraulics to pull it out tomorrow. Also need to do some straightening and welding on the hinged ramps. Like the trailer a lot but rust is just about to put it down. Even the 2X6X3/16" wall tube frame has holes rotted in it, but nothing structural yet.

I'll finish this task tomorrow afternoon and move onto something else.

Trees are celluloid beings that grow in asymmetrical stance to suit the individual location and conditions of the very spot they sprouted.

That means, they're not only NOT straight, they're internally stressed.

Cut a trunk or limb into a log, put it on a sawmill, and make a laser-straight cut through it, and slide it off onto a flat surface.  It'll be 'kinda' straight.  Let it sit for a while, moisture comes out of the exposed surfaces, which shrink, mebbie crack... but the slab you cut will no longer be flat... or straight... because internal stresses which kept it standing up in it's original spot, were asymmetrical... meaning... it grew in such a way that allowed it to stay centered with gravity, even IF there's much heavier limbs and leafage on one side of the tree (the downhill side of a slope, for instance).

Once cut, the OTHER side of the tree is no longer holding that slab in it's original fashion, so it starts shrinking based on how it grew, not how you WANT it to be.

Dimensioned Lumber is nothing more than a slab that's been run through a mill to square up it's sides, top, and bottom.  Run that slab through, and you'll get a plank, but the plank will be losing moisture due to all the 'new exposure' that occurred following it's visit by the sawmill.

Some parts of the wood naturally lose moisture faster than others, so that nicely milled plank starts to respond to shrinking that's occurring in the areas that dry faster... and you get a crooked board. 

The BEST way to 'beat' this with a trailer, would be to take the material, as SOON as you get it, and fit it into the trailer.  Reject the pieces with the 'bend' (meaning, buy extra pieces), so you don't have to heavily fight nature here... or if you're clamping, place a 2x4 across the top, and once clampled, screw the 2x4 to ALL the planks, to hold them in position... then add the next plank... and place another plank into the spot intended for next... screw it into the new, and all the old planks as well...

Another way to do it, is to use 2x4 lumber... they bend much easier.  I would STILL use deck-top blocking, clamps and wedges to get 'em in together... but they'll be much more inclined to pull it all in. 

I remember there were four, or five of these things in total with only the one I looked into not being operated. Very hot atmosphere but everything was outdoors. The vessels operating were all emitting steam and a bit on the noisy side as there was a large stationary diesel engine running pumps moving the water. Circulated water was CCA, (copper chromated arsenic) charged from a large tank and sprayed into the vessels saturating the lumber within for some given time. The lumber was then allowed to cool, removed and staged/stacked for the next process which I believe was packaging/shipment.

That all was back in the early 1990's and from memory. Did work at Keesler AFB in Biloxi, MS, Mobile, AL, New Orleans, LA, and along the roads down there are a lot of treatment plants for pine lumber.