I recently sealed a deck with Cabot Decking Stain. We poured all five one gallon cans into a 5 gal. bucket and stirred to get the proper consistancy.The deck looked beautiful. Two days after we got done I got a call from the deck owner telling me that there is a white film over much of the deck and that sections of the deck looks like it needs a second coat. Needless to say I went over there to see for myself. Sure enough there was a white film in areas and plain water would not wash it off. There also were areas that looked like it wasn't totally sealed. We hand brushed the entire deck so I know that proper amount of sealer was used over all the deck.We also waited two full sunny days before sealing.
Some info that may contribute to this problem.
1. They are on a well so we were limited to how much water we could use.
2. We were not allowed to use any stripper or other chemicals other than soap. The deck had not been sealed for at least five years so most all old sealer came off.
3. Most of the problem area is where the most traffic occurs; to and from the door.
My questions are could that film be mildew? If so will bleach take care of it? If it isn't mildew what is it? How can I get rid of it? Can I apply a second coat over the questionable areas that look like they didn't seal right? They were not areas that might have still had some old sealer.
Any help will be greatly appreciated.