internaughtfull writes:
Hi,

I had some work done on a wooden porch and some dry rot
was replaced with durham's wood putty. It dried for one day then
was painted with valspar ultra latex. It gets wet and peels.

I repainted it and covered it with plastic to allow for drying but
it still peels.

Can I just scrape this and seal it with polyurethane then use
something like Kilz on it? It is a satin white and a small area
so perfect color matching is not that important. Or does the
peeling indicate something else.


While as other posters pointed out, your primary problem is probably
that you didn't let it dry enough...

However, unless you let it dry completely and thoroughly seal all edges
of the wood with an impermeable protective layer and keep it that way
forever, then you will get movement of water in and out. However, most
putties are not really waterproof so they can run into problems with
moisture.

My solution for outside is to always use an epoxy-based product (Bondo
is OK but it tends to be more brittle and not attach as well to wood
which over time results in separation from the wood when it repeatedly
expands & contracts). It's more expensive but should be a more permanent
and professional solution.