Sanding poplar and plywood for paint

[Phil in NC]

Hey all:

I am building built-ins for my office and I will be (HVLP) spraying them with BIN shellac white primer, then a white paint topcoat (Probably Sherwin Williams Emerald Urethane) .   The cabinets are made from a good quality plywood with poplar face frames.  

The plywood faces have normal plywood smoothness slightly rough, but not too bad...  the poplar face frames are very smooth and I was wondering if I will need to rough them up a bit with sandpaper before I put the primer on?  I obviously want a smooth cabinet grade paint finish on all surfaces when I am done.   

Has anyone primed poplar with BIN shellac primer and had any problems??

  Thanks in advance.

[fredhargis]

I have, and had no problems. In fact the BIN may have helped with the smoothness. After I applied it (I brushed) I sanded it smooth, and then top coat. As I recall, I used an oil based paint on top of the BIN. These were bath cabinets, the only real project I've ever painted. So I wouldn't rough the poplar up any, if the ply has some roughness sanding to only 150 or so should get you there. The bigger problem (with all my vast experience with painted projects) was that ANY surface flaw (dents, gouges, tear out) telegraphs through the paint more so than any stain/clear coat finish. So go over everything very carefully. Here's my cabinets:

   

[jteneyck]

Hey all:

I am building built-ins for my office and I will be (HVLP) spraying them with BIN shellac white primer, then a white paint topcoat (Probably Sherwin Williams Emerald Urethane) .   The cabinets are made from a good quality plywood with poplar face frames.  

The plywood faces have normal plywood smoothness slightly rough, but not too bad...  the poplar face frames are very smooth and I was wondering if I will need to rough them up a bit with sandpaper before I put the primer on?  I obviously want a smooth cabinet grade paint finish on all surfaces when I am done.   

Has anyone primed poplar with BIN shellac primer and had any problems??

  Thanks in advance.

You definitely want to sand everything if you haven't already.  150 grit is pretty common for solid stock when I do paint grade, 220 or 325 on plywood.  You don't want to see visible scratch marks from sanding but you don't want it as smooth as a baby's bottom either.  I use BIN shellac based primer a lot to prime paint grade work.  Love the stuff.  The only reason I would use something else is if the topcoat was incompatible with it.  SW's makes a very nice wood and wall primer, but it's really thick and not nearly as easy to spray as BIN.  Be aware that Emerald is likely really thick, too, and you will need a pressure assisted gun to spray it w/o substantial thinning which is never a good idea with WB products.  

John