I sided my house this winter with pre-primed cedar bevel siding. Due to the rainy spring, I plan on sanding and repriming it. I got it pre primed mostly to get the back priming and also to protect the surface until I am ready to paint.
The question is, should I use latex or oil primer? Not sure what the original factory primer is. If I had to bet, I’d say water based, but I don’t know for sure. I suppose I should contact Mid America Cedar and find out. Seems like the conventional wisdom has always been oil based to prevent tannin bleed, but it’s been up all spring and I don’t see any tannin bleed yet. I know that latex primer is more flexible and more breathable which both seem like good traits. I could always spot prime with BIN if I have tannin bleed in spots.
What do you guys think?
Replies
I'd give it all a coat of Cabot Problem Solver oil based primer. This stuff will adhere to just about anything and leaves a great surface for their PrOVT solid stain. I'd stick with the oil based just because it seals the surface and also prevents the tannin bleed.
+1 for Cabot PS primer. Especially if it is Red Cedar. Big plus for the Cabot is for an oil primer it dries pretty fast. We use it here a lot on Long Island near the coast and it holds up extremely well.
I personally am a huge "fan" of oil (not implying that I really enjoy applying that stinky stuff...wear respirators) It just seems to me in most cases that the oil based is the way to go for longivity..But if you intend to paint shortly after priming, and you go with some good exterior UV protected paint, either the oil or latex would work.However if you don't plan on painting anytime soon, I would definitely go with the oil.
good luck either way
All I ever wanted in life was an unfair advantage...
Yeah, I've always thought that oil was it. What got me to thinking was reading this: http://www.taunton.com/finehomebuilding/PDF/Free/021161060.pdf. This article seems to be advocating latex primers.
I like it because you can sand it with fine sandpaper if you end up raising the grain. Can't do that with latex.
Thanks for the link to that article. Yes, they do seem to advocating the use of acrylic primers, but I think oil-based primers are still superior despite the advances in acrylics.
For high-tannin wood like cedar, I think you pretty much must use an oil primer.
Well, I figured out that the factory primer is oil. So I have the tannin blocker. This is just another layer of primer on top of the oil to assure adhesion--they recommend repriming after 60 days (I'm past that). I think I am going to call a paint manufacturer. I'm not afraid of oil primer, just don't want to screw this up.
I'm interested to hear what paint manufacturers have to say. Let us know. I know if I asked the pro's where I buy my paint, they would say to hit it again with oil.
But, I suppose it is possible that you don't want to seal the wood too tight because if any moisture gets in the wall, it will find it's way through an acrylic primer more easily and possibly even blister the oil primer. Of course, moisture shouldn't really be getting into the walls.
I called Diamond Vogel today. Their recommendation was a second coat of oil. His explanation was that since the existing primer has weathered a bit, there is a risk that it lost it's bite and latex could peel. He felt the best thing to stick to the existing oil is another coat of oil primer. So oil it is.He did say that if I sanded the whole thing, the latex primer would then be OK, because it would have a mechanical bond. I was thinking about doing that, but after talking to the tech support guy, I don't think it's necessary.Interestingly, he did say that if it was new, bare, cedar, his recommendation was very clear cut. Two coats of latex primer, and two latex topcoats. He said that was based on their experience and research. Kinda goes against what I thought the gospel was (oil primer, latex topcoat). I've got some extra siding, and both kinds of primer sitting around. I think I'm going to try some different combos and toss it up on my shed roof for a few years. I'll get back to you with the results.
What Abm said.
Jeff
Thanks for the update. We look forward to hearing from you.. oh, let's say sometime in 2012. Don't forget now :-)
Their recommendation of a latex primer does surprise me, however. Not only do I believe the conventional wisdom about oil primer and latex topcoat, but I've also found oil primer necessary to prevent tannin bleed with cedar.