Hello,
I had # 1 clear kiln & dry pressure treated yellow pine decking boards installed last July with ring shank galvanized nails.
I have not been able to apply a stain/sealer yet (14 months later)
Now black spots are appearing on most of the boards. It seems as if small cracks are developing and from those comes the black spots.
Tried Oxalic Acid based cleaner but made no difference - i don't think it is Iron Oxide Stains I was going to apply a light semi transparent stain but now rethinking a darker maybe solid stain to hide the spots. Any ideas what these spots are and if they will cause a problem after staining? I have attached pictures. Thanks for any help,
-Tim