Using a HVLP spray gun

[nick]

I want to know if anybody has information in regards to paint spraying on foam.

My work looks very nice but I'm looking for perfection...

Is it typical to sand after spraying with 220 or should the finish be wet and smooth.

My finishes look slightly dry, and sanding usually smoothes the high spots.

If I apply it wet then the coat looks uneven...

So I guess my question is what is the best technique to spray foam and how much paint, volume per coat works best and is sanding required, light / moderate???

Thanks

[Brady Watson]

What kind of foam? Cheap insulation foam - very hard to achieve a good clean surface...Sign foam - FSC-88 primer from Coastal Enterprises. I'm sure one of the sign guys will chime in to add their expertise.

-B

[nick]

3/4" Sign foam using FSC-88WB

[Brady Watson]

You need to dilute 88WB and blend it with a hand held blender (el cheapo from dollar store)...then spray light coats on it. Have a fan blowing on the surface when done spraying to dry & heat up the surface. Give it -->LOTS<-- of time to dry, then recoat as needed.

The other thing you can do is a Bill Palumbo trick...put on some rubber gloves and work some into the surface of the sign by hand. Then let it dry well & lightly sand. Apply subsequent coats with a brush, roller or thinned spray.

-B

[joewino]

We use FSC-88WB with a HVLP gun. Since the Texas heat makes a very good drying enviornment, we thin the primer with water (about 15-20%) and spray on several coats (don't sand between coats) until the surface is covered with a good layer of paint. We then sand with a fine grit sandpaper after the primer dries overnight. You can get a glass smooth finish if you want to sand a bunch but we normally are not that particular.

All paints are strained using a standard automotive cone strainer.

The finish coats are also water based acrylics - sprayed for the larger areas and then the trim, letters, panels, etc. are brushed. Flat paints give the smoothest finish, but we use satin if there will be vinyl applied over it. Our personal preference is the low-sheen of satin or flat.

HDU - either 15# or 20# is used on the majority of our work. SignFoam 3, Corafoam, or Precision Board Plus.