Tom Nie wrote:
Robert,
Hey, I'm thinking of a "HVLP" gun with gravity can for a regular compressor
and then painting interior 6 panel doors with latex. Your post reminded me
of all the experience you have. What comments? Too thick to spray? How do
you avoid dust/crap when on a job site? Shoot 'em vertical or laying on
sawhorses? Email me if you'd rather. Thanks.
TomNie

Hello, Tom. It's raining like hell here, so perfect time for this
question.

A few months ago I was looking at different guns to use as a utility
sprayer as opposed to using my Fuji Turbine or high pressure guns every
time I needed to spray something. My criteria was to find a gun with a
air cap (nozzle/needle assembly) that hit in between what I need for
oil base and latex coatings. Something that would be really easy to
clean. I found this gun:


http://www.harborfreight.com/cpi/cta...emnumber=90977

This is honestly a nice gun, and I cannot tell you how surprised I was.
When I bought mine, it was on sale for $39, but it is well worth the
$59 they have on the site. It is nicely polished and the
trigger/packing is a smooth as my $300 guns. I was just looking for a
gun that I could use on occasion for utility work as oppposed to
finishing, but the more I use this one the more I like it. I can run
it with my 2 1/5 compressor just fine, which is totally unlike the
other conversion HVLPs that need around 14 cfm or so. That means I can
take it out to the job and use my roll around compressor that is on the
job to run my nail guns. That also means that I can do a lot of
different finishing and priming by throwing the gun on the front seat
instead of loading my HVLP turbine or my airless. So far I have shot
primers, lacquers, oil based urethanes and industrial quick dry enamels
with it and just love it.

Back to doors. When I spray a door, I do put it on saw horses for prep
then finish. With latex products, they will dry, but they will stay
soft. So I plywood the door hole it is from (unless it is new
construction) so I can have the door for a while to let the finishes
cure.

Here's what I do. Put the door on the horses and sand/fill/clean as
needed. Then I drill two 1/4" (maybe 5/16") holes about 2 1/2" deep in
the top and bottom of the door, space so that they are just a little
less farther apart than the width of the sawhorses. Then I put a 40d
nail in each hole and suspend the door by the nails over the saw horses
(the door is held suspended by the nails). Wash the door with lacquer
thinner to remove any grease, wax, or stearates from your sandpaper.

While the door is drying, mix your primer. For a door I can spray and
not worry about fumes, I use the original KILZ, cut by about 5 - 10%.
The hotter it is, the closer I get to 5%. You can get on this with you
latex in about 30 - 45 minutes. (I know, the can says less...)

When working on a door I have to worry about the fumes, I use the water
based KILZ 2, and thin it about 20% (OK - sometimes as much as 30% but
then put on two coats) to spray with this gun. Sprays like a dream.

Mix your paint after you practice with some of it. Not being familiar
with a certain piece of equipment makes me practice on scrap, not on
projects. I would buy a gallon of the paint you like and start from
there. To spray latex, you will need to keep the pressure up and thin
it properly. Thin the paint you choose (this can really vary, so it is
important to experiment) about 20%. I usually start the gun out around
20 pounds of pressure and then open the needle to get how much paint I
want to come out at one time. Since it is latex, and door in your
case, open the fan pattern up to about 7- 8" when you hold the spray
tip of the gun about 8-10 inches off the surface. I work up the
pressure to finish ratio to get what I want, using batches of different
thinned mixes made in paper cups from the dollar store. If you do it
that way, you will still have enough out of your gallon after
experimenting to spray a couple of doors.

Remember that shooting HVLP is not high pressure. HVLP will shoot
larger droplets of finish that will lay out when the finish dries and
contracts. High pressure sprayers actually "atomize" the finish and
spray out tiny droplets (requiring less thinning) that do the same
thing, but just all over every where. Most people don't understand the
big deal about HVLP as they never get their guns/finish mixture right,
and they have almost as much overspray as they do with high pressure.
Don't be afraid to thin more and turn that pressure down. I mean way
down - you can always turn it right back up to find that sweet spot.

Write down the thin mix for the type of paint you use as well as the
gun/compressor/regulator settings. When you decide to do another
project with that paint, you will just need to fine tune before you
start spraying.

Spray one side of the door, but not the edges. Flip the wet door over
by the nails and edges, resting it on the nails again. Spray the edges
(get in close as possible, move quickly to get as little as possible on
the door face, then spray the door face. Let the door dry, spray,
flip, repeat. You should be able to get the door primed and two coats
of finish on it in a day. I usually go in the next day and spray a
final coat if it is an exterior door. If it is interior woodwork, I am
finished at two coats paint.

One more thing, if I am spraying outside and the project is in sunlight
(definite no-no) or it is windy or buggy, I use one of those $49
canopies that the picnic guys use. The small one works great.

Let me know here if you got this, or if you need anything else.

Good luck!

Robert