Today I will start sanding the treated wood deck prior to its initial applying of Sikkens next week. Directions are to use 80 -120 grit. No problem generally.
Ques: the deck boards are the typical treated wood 6" wide with rounded edges. They are installed with min. of spacing (1/8"). So it is going to be difficult to get much sanding done on the rounded edges. Should I bother?
Concern: My belt sander might just mess up the factory rounded edges too much. Hand sanding the board edges on such a large deck is impractical.
The major issue is going to be what the stain penetration and color difference ends up being like if you do not sand the edges. I doubt it will be that much of a problem but try a little test section to put your mind at ease.
Years ago I bought a new Dremel contour sanding kit for $10 at a parking lot inventory reduction sale. I think Dremel was trying to get $100 otherwise for the kit which struck me as a bit absurd. It is by no means a production tool but I do find it more handy than I ever thought for situations like you face. I use it a lot for sanding antique window frame details and so forth. As with anything Dremel the paper is expensive but I suspect Harbor Freight sells alternatives. You might check Amazon, eBay, etc. to see if something similar pops up at a decent price.