Primer question

OK, so I've convinced myself that I don't need to prime everything. I will prime mating surfaces and non-alclad parts. The question I have is that many of my parts, during the dimpling and drilling process, have developed numerous small scratches. Do I need to buff these out and prime them, or are they small enough that they can be left?

Ok I'll bite....if you are not going to prime everything then why prime at all. I have worked on many old and corroded Cessnas and pipers that were never internally primed when they were built. If these planes had primer applied to just the mating surfaces of structural members then they would have a little less corrosion, but would still be a mess.

If you don't care what the condition of your plane is in twenty years from now then don't prime it!

To answer your question, primer - especially applied to alclad material - should be preceded with some kind of cleaning / scrubbing treatment. Most builders opt for a bit of scotchbrite buffing with soapy water, followed by a degreasing wipe with MEK or acetone. The buffing will mitigate any small scratches.

Most Excellent..... Dude !

Primers, Mmmm

Spray it, move on, no worries...

Think this.

Mr Cessna, Mr Beech and Mr Piper didn't do anything at all.