Repair rotted beam

[zakthor]

Originally Posted by rfuerst911sc

Why not use an oil based stain for top coat ? It should protect the wood better than latex .

Right. It was a big mistake to have this thing painted in the first place. Not even sure I could call the paint latex it was sherwin williams 'superpaint'. The paint held its shape but locked the water in and the wood rotted away without us noticing.

I called cabots, zinsser and a few other company's tech lines for advice. Consensus seemed to be that best protection is a thin oil sealer to the dry sanded wood followed by a few months of weather, then a scuff sand and water based acrylic solid stain. After that its water based solid stain forever. They said the new water based holds up a lot better than the old oil based stains and will stick over oil. Cabots still sells an oil solid stain where i live but they said it wasn't nearly as good. I tried the water based direct to a scrap of wood but it doesn't soak in at all, I just can't believe it will last by itself, but wow that oil does soak in.

But one lady at cabots sure gave me grief because I was applying their oil completely wrong.

Originally Posted by 911 Rod

Maybe it depends on where you are?
The PT here is a very pleasing colour since they dropped the green years ago.
No one stains or paints it other than for looks. (I'm not an expert though)

Ok, so what I've read is that the good pt is incised so the poison gets into the heart of the wood. There is non-incised pressure treated, even kiln dried, but it doesn't last as well as cedar. I've never seen that stuff. The pressure treated here is not something you'd want to look at but will survive ground contact.