Kevin,

 

When it comes to bodywork and priming, you're likely to get 20 different answers from 20 people.  That said, here's my version.

 

I used WLS and thought it worked fine.  Really blow off the surface first to get the dust out of the pinholes or the primer won't soak down into the holes.  Roll on the first two coats with a foam roller, using a Bondo squeegee to work it down into the weave.  Then roll it smooth after squeegeeing.  No reducer in the rolled on coats.  Sand the first two coats.

 

I would spray all additional coats.  The thing about rolling is your primer buildup is only as thick as the thinnest part of your coat.  And when you roll, you get texture.  It takes a few strokes of sanding to knock off the texture and there's very little primer buildup left to fill your low spots.  I probably wasted 2 gallons of very expensive primer learning that lesson.  Spraying gives a smooth and even thickness coat.  I sprayed WLS with very little reducer added, just enough so it would spray well through the gun.  I wanted maximum build.  Unlike paint, primer practically dries before it hits the hangar floor.  So masking and cleanup aren't that bad in my opinion.  I bought a cheap HVLP gun at Harbor Freight and it worked very well with WLS and other primer-surfacers I used.  The left over reducer works great for cleaning the gun.

 

The time you save in rolling over spraying is not worth it when you figure in the amount of primer that's wasted due to the roller texture.

 

Mike Easley

Colorado Springs

Super ES

 

PS  I tried water based primer and it had less build and takes longer to dry than the WLS.