Can I leave a wall primed, but without paint, for several sunny months?

Question

I notice the siding and trim on my house is in urgent need of paint, as there are bare areas of wood where the paint is flaking off, but due to uncertainties with Coronavirus, I need to hold off on buying thousands of dollars worth of paint. I do, however, have lots of KILZ 2 primer leftover from another job.

Can I paint my house using just primer, to protect the house during this harsh Southwest summer, then add the actual exterior paint in the winter? Will rain or sun, etc. have some negative affect on the primer in the meantime? Will the primer protect the wood?

Answer 1

It depends on the primer. PPG has over 100 different types of primers.

https://www.ppgpaints.com/search?term=primer

Edit: Since you referenced KILZ 2 primer, and I’ve been asked to direct comments on it specifically, I’ll elaborate: 1) KILZ 2 primer comes in various types: interior/ exterior, mold resistant, etc. Depending on the exact type, some perform better than others, 2) KILZ 2 primer is a latex primer. Latex primers have a shelf life and limited performance, 3) Some primers have a UV resistance, this primer does not stipulate that criteria,

However, leaving wood siding and trim exposed to the weather is dangerous and may cause the material to be replaced.

Summary: If the primer goes “bad” and needs to be touched up in a year or so, it’s still better than leaving wood untreated and exposed to the weather.