Learning to spray paint

I've assembled my compressor, mounted a regulator/filter, have done
some sandblasting, and done some grinding with my die grinder. Now
it's time to learn how to use the paint sprayer.

I've been spraying water on a cardboard surface, but the viscosity/
volitility of water is such that I fear I'm not getting much out of
the exercise.

My end objective is to spray 2-part epoxy primer, but that's expensive
to learn on.

Any suggestions on an inexpensive medium to practice with? Enamel
diluted IAW directions? Interior housepaint? - Mike

On Mon, 20 Aug 2007 06:08:51 -0700, mhorowit wrote:

I've assembled my compressor, mounted a regulator/filter, have done
some sandblasting, and done some grinding with my die grinder. Now
it's time to learn how to use the paint sprayer.

I've been spraying water on a cardboard surface, but the viscosity/
volitility of water is such that I fear I'm not getting much out of
the exercise.

My end objective is to spray 2-part epoxy primer, but that's expensive
to learn on.

Any suggestions on an inexpensive medium to practice with? Enamel
diluted IAW directions? Interior housepaint? - Mike

be sure to put a water trap in the air line. mine is a sintered jobbie
which combines a step down pressure regulator in one.

I had a friend who painted an Aeronca fuselage with a commercial spray
gun. at the end of the job he guessed that the overspray on the floor
was worth over $200.

I took the hint and sprayed my entire Auster fuselage with enough
overspray to leave just the faintest green dust on the floor. cost of
the overspray was probably $2.

what I used was a miniature Revel type airbrush. it gave a spray just
as wide as the tube and actually sprayed just as fast as a full size
gun. The revel type is the really simple airbrush with the plastic
handle, on off air button control and the little glass bottle. It
blows air past a paint nozzle just like a flit gun.

I found that the airbrush would eventually gum up with dry epoxy paint
even when washed out in solvents.
They cost me $14 each in various shops and over the course of the
fuselage spray task I used 4 of them.

The other benefit is that they spray so little solvent into the air
that you have a far healthier environment to work in.

dont be fooled by the diminutive size of the airbrush. they actually
work beautifully on tube fuselages.

One thing I found is that it is easy to miss the face of a tube. have
someone else look over the fuselage for missed areas. You'll find them
guaranteed.

I practised on the first tubes with the actual thinned epoxy paint.

Stealth Pilot

On Aug 20, 10:34 am, Stealth Pilot
wrote:
On Mon, 20 Aug 2007 06:08:51 -0700, mhorowit wrote:
I've assembled my compressor, mounted a regulator/filter, have done
some sandblasting, and done some grinding with my die grinder. Now
it's time to learn how to use the paint sprayer.

I've been spraying water on a cardboard surface, but the viscosity/
volitility of water is such that I fear I'm not getting much out of
the exercise.

My end objective is to spray 2-part epoxy primer, but that's expensive
to learn on.

Any suggestions on an inexpensive medium to practice with? Enamel
diluted IAW directions? Interior housepaint? - Mike

be sure to put a water trap in the air line. mine is a sintered jobbie
which combines a step down pressure regulator in one.

I had a friend who painted an Aeronca fuselage with a commercial spray
gun. at the end of the job he guessed that the overspray on the floor
was worth over $200.

I took the hint and sprayed my entire Auster fuselage with enough
overspray to leave just the faintest green dust on the floor. cost of
the overspray was probably $2.

what I used was a miniature Revel type airbrush. it gave a spray just
as wide as the tube and actually sprayed just as fast as a full size
gun. The revel type is the really simple airbrush with the plastic
handle, on off air button control and the little glass bottle. It
blows air past a paint nozzle just like a flit gun.

I found that the airbrush would eventually gum up with dry epoxy paint
even when washed out in solvents.
They cost me $14 each in various shops and over the course of the
fuselage spray task I used 4 of them.

The other benefit is that they spray so little solvent into the air
that you have a far healthier environment to work in.

dont be fooled by the diminutive size of the airbrush. they actually
work beautifully on tube fuselages.

One thing I found is that it is easy to miss the face of a tube. have
someone else look over the fuselage for missed areas. You'll find them
guaranteed.

I practised on the first tubes with the actual thinned epoxy paint.

Stealth Pilot

A winner! I was worried about overspraying the neighborhood. I'll
GOOGLE for Revel+airbrush - Mike

"mhorowit" wrote

A winner! I was worried about overspraying the neighborhood. I'll
GOOGLE for Revel+airbrush - Mike

The water trap suggestions should be taken as a "must."

I am not sure how it carries to using an airbrush, but I would imagine that
it does.

I use a HVLP conversion sprayer, which is High Volume Low Pressure and the
conversion means it takes relatively high compressor pressure, and regulates
it downward, to as low as 15 pounds per square inch. The higher pressures
atomize the paint better, but at the cost of more over spray. A decent 100
buck HVLP can also spray a very narrow pattern, and when used with low
pressure, almost no overspray.

For water control, I made a primary water trap myself, then used a
filter/desiccant to get the air really dry. You can get them at NAPA, and
they go inline right before the gun.

For my water trap, (follow along carefully, here g) I took the air from
the compressor, and went into a 1 1/4" T, with the air coming in the side.
On the bottom side of the T, there is a petcock (valve) to drain out water
once it accumulates. You can also leave it open a very small amount, and
water will dribble out. In the top of the T, there is a 6' tall 1 1/4"
steel pipe, and at the top a reducing coupler, which goes to a regulator,
and then to a quick connector to hook your air line into, going to your
sprayer.

The trap works better than commercial units for two reasons. One, is that
the small air line going into a large pipe will allow the air to cool, and
will cause the water vapor to condense out. Two, since the air is moving so
slowly, the water will run down the sides of the pipe, and can drain out the
bottom.
--
Jim in NC

Morgans wrote:

The water trap suggestions should be taken as a "must."

I am not sure how it carries to using an airbrush, but I would imagine that
it does.

I use a HVLP conversion sprayer, which is High Volume Low Pressure and the
conversion means it takes relatively high compressor pressure, and regulates
it downward, to as low as 15 pounds per square inch. The higher pressures
atomize the paint better, but at the cost of more over spray. A decent 100
buck HVLP can also spray a very narrow pattern, and when used with low
pressure, almost no overspray.

For water control, I made a primary water trap myself, then used a
filter/desiccant to get the air really dry. You can get them at NAPA, and
they go inline right before the gun.

For my water trap, (follow along carefully, here g) I took the air from
the compressor, and went into a 1 1/4" T, with the air coming in the side.
On the bottom side of the T, there is a petcock (valve) to drain out water
once it accumulates. You can also leave it open a very small amount, and
water will dribble out. In the top of the T, there is a 6' tall 1 1/4"
steel pipe, and at the top a reducing coupler, which goes to a regulator,
and then to a quick connector to hook your air line into, going to your
sprayer.

The trap works better than commercial units for two reasons. One, is that
the small air line going into a large pipe will allow the air to cool, and
will cause the water vapor to condense out. Two, since the air is moving so
slowly, the water will run down the sides of the pipe, and can drain out the
bottom.


I second the HVLP approach.
Mine is a $90 Harbor Freight cheapie that I've used for the last 8 years.

It makes very little overspray, and works fine.

Richard

"cavelamb himself" wrote

I second the HVLP approach.
Mine is a $90 Harbor Freight cheapie that I've used for the last 8 years.

It makes very little overspray, and works fine.

I should add that there is not enough tea in China to make me spray a
fuselage with an airbrush, when I could fill the quart HVLP gun one time, or
perhaps two, and do it all. The waste factor difference would be very
small, indeed.
--
Jim in NC