B A R R Y wrote:

Dave H wrote:
Has anyone tried putting on the final finish to a project using an
airbrush as the application tool for either water based or oil based
polyurethane? If so, any recommendations on brand and model of the
airbrus
For what project?

Airbrushes are fantastic for models, small instruments, small toys,
figurines etc... where very thin coats are required so details aren't
obscured. An airbrush sprays an even finer coat than a typical spray
bomb, so more coats are required to build a decent finish thickness,
which isn't usually wanted or required where a typical airbrush is
the best tool. Most airbrushes are also limited to about 2 oz. of
finish per filling, further limiting the project size.

That said, if I'm choosing the airbrush to spray a clear top coat,
I'm also choosing lacquer or shellac, for a fast, dust-free coat and
very thin "shell". All in all, I really don't know how polyurethane
varnish would spray with an airbrush. G On the other hand,
oil-based polyurethane is sold every minute in spray bombs, so I
don't think it would be a problem if properly thinned. Water base
polyurethane might be more difficult.

When we're talking top coats, even something as small as a typical
electric guitar body is usually better sprayed with at least a
"touch-up" gun.

Thank you for you input. My intent was to apply polyurethane as I had
in the past using either a brush or wipe on poly and build up the
finish with 3 or 4 coats. No matter how careful they are applied, the
last coat often contains small bubbles that break as it dries leaving a
less than perfectly smooth finish. What I was hoping to accomplish was
to sand the last coat as I had the others, removing all the
imperfections, and then applying a final thin bubble free coat that
only needs to be think enough to fill in the sanding scratches of 220
or 300 grit sandpaper.

I just don't have the space to set up a large spray booth and air
handler to use a traditional HVLP spray system.

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