Dull Coat, spray vs. brush

Callandor · Post by **Callandor** » Fri Aug 26, 2011 10:25 am

I am finishing up my AMT runabout and I brushed on some MM Acrylic flat coat onto some cement that has seaped out of a seam. The cement was very shiny and I wanted to dull it down. The flat coat I brushed on came out as more of a semigloss or satin. The subassemblies had already been sprayed with the same flat coat through an airbrush. Is there a reason the brushed on stuff isn't as flat as the sprayed on dullcoat?

Kylwell · Post by **Kylwell** » Fri Aug 26, 2011 11:55 am

Possibly it didn't layer as flat as the spray. Give it a few more coats.

Callandor · Post by **Callandor** » Fri Aug 26, 2011 12:43 pm

The weird thing is that it is actually making the original coat of flat look LESS flat.

Kylwell · Post by **Kylwell** » Fri Aug 26, 2011 12:48 pm

Might not have been mixed enough then. I've had flat coats come out satin because I didn't shake it well enough.

seam-filler · Post by **seam-filler** » Mon Sep 05, 2011 5:53 am

Brushing a coat of varnish will usually produce a slightly glossier finish than spraying will. The reason is that spraying a varnish delivers the liquid as tiny droplets which are probably half way to being dry when they hit the model. These tiny droplets make the surface marginally rougher and hence more matt. Brushed-on varnish flowss to find its own smooth surface.

To prove this, try spraying a gloss varnish further and further from the model. You will find that by spraying far away enough can give you a completely matt finish!