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Bought this thing to use with waterborne poly. Had good success with thinned
latex paint, but this was my first attempt with sprayed waterborne poly. Up to
now had used foam brushes (25 different projects, so lots of practice!).
Targets were two hope chests, both stained with waterborne stain (old stash of
Carver-Tripp Safe&Simple). All surfaces were vertical, with the chests upside
down on "turntables" and the lids hanging on the wall with nails. My shop
humidity was high (75-80%), which is actually an advantage with waterbornes
(more below).
The finish was Parks Pro Finisher bought at HD. Got good marks in a FWW review
(#133, Dec.98) and price was right in a gallon container. Didn't thin, or even
strain it, just ladled it right into the gun pot.
Gun settings were: 2 to 2-1/2 threads showing on material flow knob, and air
flow around halfway. Round pattern works the best. (The fan patterns caused
some orange peel, due to the water evaporating). Used the "general purpose"
needle/nozzle set - not sure whether the thin material nozzle would make a
difference since everything came out great. I'll try it next time just to see.
Waterbornes flow out really well as long as there's enough finish applied to
wet it, but the risk is to put on too much and end up with runs or sags,
especially with vertical surfaces. They dry fast so you have to catch the runs
early with a foam brush. Too little finish and it dries before it can flow out
yielding an orange peel texture. Higher humidities actually help out since the
drying time is slowed.
No problem controlling the coat with the CH sprayer, even on these vertical
surfaces. The finish goes on milky or cloudy, then dries clear, so it's fairly
easy to tell when you've got enough on. Did some brushing, just to compare,
and found _no_ trouble with bubbles or foaming, another potential headache
with waterborne. Wore a light dust mask and goggles, but overspray and odor
was so minor I probably didn't need them. My shop is ventilated with a box fan
hanging on a storm door next to where I spray. I also have a oscillating fan
at the other end of the shop to keep a postive flow towards the box fan.
My finishing schedule was the same as brushing: 2 coats, sand 220, 2 more,
sand again, 2 final coats. Each coat goes on thin, and dried in 30 to 45
minutes. Waited around 90 minutes before sanding. No problem with grain
raising, and the finish sands out very nicely. Didn't clean the gun between
coats, and final clean up took less than 10 minutes.
Like KC, I'll never look back. Since the system is quick to set up and clean,
I'd use it even for small projects. The results are wonderful, and my
productivity will be greatly improved. Got a throw-away camera and I'll take
some project and shop shots for posting later.
Following up on my previous post:
Using the Campbell-Hausfeld HV2000 Turbine HVLP, $199 at HD. Spraying Park's
Pro Finish waterborne poly (also from HD) straight from can. Target is a
panel&frame constructed curio cabinet 6' tall, 3' wide plus framed glass
shelves and two doors.
Used thin material needle/nozzle set this time - it comes with the sprayer.
Ended up with gun settings of air flow half-way and about 2 to 2-1/2 turns
showing on material flow adjust. Used mostly the round pattern. These gun
settings are essentially the same as my previous tests using the general
purpose nozzle.
The thin material nozzle was a big improvement, with a smaller spray pattern
and no tendency for orange peel (I guess this means better atomization). Even
less overspray with this setup. Better adjustment range using the air flow and
material flow adjustments, going from almost an air brush type spray for the
trim/moldings up to a broader pattern (maybe 1-1/2 to 2" wide) for the case
structure. Only minor problem was a tendency for a small amount of poly drying
at the nozzle tip with the unit at rest. With the turbine off and the trigger
squeezed to retract the needle, a quick wip with a damp rag took care of it.
Four coats did it here: 2 coats, sand 220, 2 more coats. Large casework is why
I bought the CH HVLP in the first place, and I am really happy with these
results. Saved many hours over foam brushing with better quality.
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