My pool deck has water based paint on top of (apparently) xylene based paint. In some areas the water based 2nd coat has chipped off creating a big mess. I ran an experiment, by pressure cleaning ( got some of 2nd coat off, but not all), vacuuming, then per advice of Home Depot I applied Seal Kote Lockdown Concrete Bonding Primer, followed by Behr Premium 1 part Epoxy Concrete Floor Paint. This was applied in several test areas, with and without the bonding primer.
I waited one week, then tested the test areas by affixing heavy duct tape, then pulling it off.
In the areas where it had being chipping off, the tape came up with paint chips-no good. In areas where no paint had been chipping it was OK. There was no difference between areas with or without the bonding primer. Of course I want to paint all areas the same.
What should I do? The area is large, 2000 square feet. Location, south Florida.
It passed the test. I now have painted the whole deck. Looks great! Thanks for the help.
It is unclear to me if you were down to bare concrete? The bonding primer is only intended to be used directly on concrete, not over existing paint.
No. It was no down to the concrete.
So - here is what I have experienced in the past:
Xylene is not very friendly to latex paint. In fact it will not adhere or last very long when painted over. However, I have found that once the surface is power washed and all the weak spots have given up any loose paint - what sticks will most likely remain that way. At this stage I would prime the whole surface with Cover-stain oil based primer or Stix waterborne bonding primer (on line only).
Simply apply the 1 part epoxy paint over the primer and you should be problem free for several years. The main thing to remember is that moisture is the enemy here - so keep an eye out for small cracks and seal them immediately.
Thanks Paint Pro. I bought the Zinsser Cover Stain, and have applied my water based finish coat on it as an experiment. I will report the results in one week.