I have some large fir beams that stick out from under the roof line, and they have deteriorated. The beams were last painted with exterior latex paint, which didn't work very well in keeping the moisture out. So I'm going to be digging out the rotted parts and putting in filler.
But some portions of the beams are still ok, for now. Do I have to remove all of the latex paint, and then put on an oil-based primer/sealer in order to get good protection? Or would it be possible to leave the good parts as they are, but cover them as well as the repaired portions with a latex primer? I see that Valspar has a latex primer, and perhaps there are others that would work.
It would be very difficult to remove all of the old latex. The beams are quite rough, with lots of raw wood texture, and I'm concerned that even with a chemical stripper I wouldn't get all of it out. And you know, if possible I'd like to not make a career of this.
I should say that in the end the beams will be painted with the same exterior latex paint I'll use for the trim. So I guess I was just hoping I could find a way to stay with latex all the way through, and avoid issues of what I can paint over what. But I'm just not sure that will work for a fir beam sticking out in the rain. I have made metal caps for the beams from gutter stock, and that may help some.
I would appreciate any suggestions on how to proceed.