On Aug 30, 10:01 pm, "Mike Marlow" wrote:
SNIP of other great information and timely advice...
Oh yeah - one more thing... The only thing more important to keep clean
than a woman, is your paint gun and accessories. All bets are off unless
you're really, really anal about cleanliness with paint stuff.
Amen... nicely said. When I am SURE the guns and lines are clean, I
shoot just a little more solvent through the system one more time.
And make sure your filters are clean. If you don't have filters on
your gun itself, you really need them, especially with HVLP. A siphon
gun will pick up debris and dirt that doesn't go into the bottom of
the paint cup or into the edge creases of cup. But since HVLP is
actually pressured, it can push debris into the gun itself. Either
way you need gun filters.
Debris in the gun can cause irregular orange peel as it will cause
intermittent "splatter" that can sometimes be so fine in nature that
it looks like orange peel. Or it can be just plain old splattering in
appearance. Old finish (30 days is old to me... 2 years is "aged to
perfection" for my amigos) can thicken and cause gelling of the finish
that can make consistent spray texture impossible to achieve because
you cannot regulate the flow of material, hence you cannot set the
pressure correctly for the material.
Personally, I really like the ones on this page. Go a little over 3/4
of the way down and look at the Worthy strainers and click on the
links so you can see how they attach, and inside one of the hot links
you can see a close up of the mesh and filter itself.
http://www.phelpsrefinishing.com/accessories.html
I think too, the underlying message Mssr. Marlow was sending you was
to practice, practice, practice. If you are really going to get where
you can spray a given finish at any given time under a variety of
conditions you have to learn 1) your equipment and 2) your finish.
With that in mind, you still have to practice.
Keep good notes of what you have done; record what works and what
doesn't. Temps, humidity, time of day, mixes, materials, solvents,
gun settings, aircap size, manufacturers of your solvents and
finishes.... everything.
Then be prepared for the days nothing works. They are discouraging,
but you have to look at them as part of the process as well. But you
can help reduce those days dramatically by being bold with with your
mixing and spraying by practicing on your scraps, not on your
projects.
When I was learning how to mix the NC lacquer I am using now, I went
down to the Habitat for Humanity store and bought some spintered door
skins. I sprayed and sprayed those skins with different mixes,
pressures and aircaps to get what I wanted.
As a sidebar, my worst problem with technique when using my HVLP was
not maintaining the proper distance of the aircap to the surface when
spraying. After reading and understanding a dissertation from Michael
Dresdner on this (which is not that critical with high pressure), I
was convinced how critical this part of HVLP was when I saw a stop
action photo that showed the fully developed pattern had blossomed 8"
from the aircap/gun. Before that, the pattern was not developed;
after that, it broke apart.
My solution? Laugh if you want. I cut a 3/4" x 3/4" x 8" stick and
put it in my pocket and when I am spraying after a layoff or in a
place that have difficult footing or lighting. When I am ready to
shoot, I take the stick out (go ahead... laugh) and put it in front of
the gun to determine the correct distance. Then I move my gauge and
keep the distance as close to the gauge distance as possible.
Search the archives on this forum, too. There is a lot of good info
back there on setting up guns, setting up power plants, mixes, etc.
No matter how much you think you are screwing up, unless they are (as
Mark Twain put it) "disremembering" every single person that does
serious finishing has sanded their share of finishes down to start
over. Screwing up or unsatisfactory finsihes are just part of this
process.
Robert