Oil or Latex Primer - Contractor Talk - Professional Construction and Remodeling Forum

corky · 04-13-2008, 11:54 AM

We are starting work on an old Historical home,wood lap siding,with several coats of paint.After the prep is complete,am debating whether to use an oil based primer or latex primer.We are going to topcoat with SW duration.I believe with the house being as old as it is it probably has at least one coat of oil based paint underneath the latex coats.Oil based primer would seal good but does not breathe well.Part of the problem is they had the house insulated,blown in from the outside and since then they said the paint was popping off,peeling bad.Moisture problem?Latex primer breathes well,but what primer would help with the peeling problem? thanks, Doug.Also thinking of XIM peel bond?

Paintpimp · 04-14-2008, 10:01 AM

Find out why the paint peeled right after insulating. Don't paint it til its fixed. Paint won't fix the problem. As far as primer, I would use the oil primer.

Chris G · 04-14-2008, 11:03 AM

You may want to topcoat in oil as well.

If there is a layer of oil on there now, and I am sure there is, it has become dry and brittle over the years. When you put a latex over top of that, it will be fine for a few weeks, but latex shrinks as it cures and it will begin to slowly pull off the brittle oil underneath it. You may see large (2 inch round or so) peels show up.

I am not saying it will happen. But probably. I have seen and I have done it. Do lots and lots of research on this before you decide. Lots. Like...a lot.

Chris G · 04-14-2008, 11:12 AM

Hmm, okay, I may be wrong about the topcoat pulling off the oil. These guys say it is latex primer that causes it. Still though. I am not totally convinced. This is from the U.S. Historical Preservation Procedures, read it all...or weep later:

http://w3.gsa.gov/web/p/hptp.nsf/0/8...1?OpenDocument

Steve Richards · 04-14-2008, 06:21 PM

Interesting read, thanks Chris.

I did some work for the historical society here in Blackhawk, CO.

(they were VERY particular!)