Can I trim down deck boards using a planer or thicknesser?

[tal_itha]

My DIY low-level deck has been moving at a glacial pace the last couple of years. However the frame is finally finished and I'm ready to lay my boards... but I've hit a bit of a snag. well, a couple of them actually.

The boards were stored under a tarp in my carport. But they still got some water damage to them. some have cupped, others just have really stubborn watermarks that a couple of rounds of napisan and digger's rust remover haven't budged. I've also tried my belt sander, but its going through 1 battery cycle a board.

Also, even if all those boards were good, I underestimated, and I need more than I originally purchased.

The big catch - I can't find them ANYWHERE anymore. and I mean, anywhere. I've tried at least 12 different places. They are 90x22, and I can only find 86x19. I'm not too bothered by the width, that 4mm would be imperceptible really, especially if I mix them all in. But the height difference you'd definitely feel underfoot.

My question is, could I get an electric planer like this Ozito one ) or even a thicknesser (like this Ozito one) and use it to take 3mm off of the boards I already have? My thinking is that it would mean I can use the existing boards with some new boards mixed in, but also that it would help get rid of more of the water marks and cupping in the damaged boards.

Is there a catch to doing this? Something that I haven't thought of? I considered the effect to the slightly rounded edging of the boards, but if its 1.5mm off each side, I can't imagine that would be too big of a deal?

Obviously, an electric planer is much cheaper than a thicknesser - is there a huge learning curve or labour burden associated with the planer that would make the thicknesser more appropriate?

It isn't a huge deck - I have about 90lm of existing boards, and need about 110lm all up.

Any help is appreciated!

the 90x22 boards I already have

[Dave-1]

Afternoon @Noyade 

Now thats an interesting question... Mine were cupped with the rounded side down but they were insitu and no way was I removing them (screws were locked tighter then tight)

For a fresh install if the cupping isnt too bad id probarlly go cup side up like your sketch.but "shrugs" I really couldnt say which is the right way

Dave

[JoeAzza]

Hi @tal_itha , I have just checked Bunnings website, they hay 90 x22 mm treated pine decking, not sure what material you have  at home, if it’s not treated pine, you coat the whole deck with a dark stain decking finish, hopefully it might match, or you could paint the deck using decking paint, I have painted an old deck, with normal house paint, it has lasted  for a few years now. One plus in painting is that you don’t need to revisit yearly using decking stain.

https://www.bunnings.com.au/90-x-22mm-decking-h3-treated-pine-2-4m_p8032583