painting roof for insulation properties

[dmbwest]

Wow, strong growth. Assuming you did but gotta ask ... Did you try it straight ? Have a way to keep it from running off ?

Never tried it on painted surface but works for gelcoat ... Oxalic acid ( need elbow grease ) or next step stronger ... Muriatic > just spray on. Both of these are o.k for new gelcoat and semi safe for older ( starting to get chalky ) gelcoat. However, both i believe would etch a painted surface or at least open the 'grain' of it. Might be worth the trade off on an older already surface to get the slime off ?

Thinking out loud here ... Would Round Up work ?

aloha,
pog