kylemorley
Member
I was doing some reading on primers and was interested to find that Alkyd primers (the good ones sold by the industrial divisions of paint companies, or specialized suppliers like Zero Rust), not the hardware store stuff) are actually pretty good, especially for use over old paint and rust, on surfaces that are not cleaned to the white.
The alkyds apparently excel in a quality called "wetting out", that is, their ability to cover and penetrate so they tend to seal off rust and glue down any flaking old paint. Since they will be topcoated, Alkyd's main weakness, poor UV resistance and chalking, is not a problem. And they are real easy to touch up.
Just about all the big manufacturers have high performance alkyd primers in their lines, and they are often the recommended primer for use over old finishes, and as a primer for the urethane modified alkyds like Sher Kem, Moore M21 and Coronado Rust Skat.
The alkyds apparently excel in a quality called "wetting out", that is, their ability to cover and penetrate so they tend to seal off rust and glue down any flaking old paint. Since they will be topcoated, Alkyd's main weakness, poor UV resistance and chalking, is not a problem. And they are real easy to touch up.
Just about all the big manufacturers have high performance alkyd primers in their lines, and they are often the recommended primer for use over old finishes, and as a primer for the urethane modified alkyds like Sher Kem, Moore M21 and Coronado Rust Skat.