Painting over Helmsman Spar urethane

[WarPony]

Will outdoor latex paint stick to this stuff? The reason I ask is because I don't have time to put the aluminum skin on the roof of my tiny trailer before I leave for vacation so I wanted to put some sort of something on top in case it rains. I have a tempered hardboard skin with a couple of coats of Spar on it but I don't know if I trust it not to soak with water if I drive in the rain. It's not a big deal at camp because I have a screenhouse to park under. All of you who remember my trailer at the ITG event, yeah, it still looks the same but I do have side windows in now (that is a whole different world of frustration).

I'll still put on the aluminum skin this winter but don't want more trouble down the road by trying to get glue to stick to the latex paint before adding the skin on. Maybe a waterproof primer, if there is such a thing?

[doug hodder]

Jeff...if it were me, i'd just do another coat or 2 of the helmsman....you know it is going to bond to what you already have...that way when you get ready to do the top, you don't have to worry about some layer of incompatible material that might not be bonding very well underneath....I would scuff sand your existing finish to make sure that it has a tooth to bond to..lay it down with a foam roller....unless you want a uniform color coat not what you already have.....just my opinion....doug