HVLP spray painting

By telleropnul, May 15, 2022

Checklist
– paint station work area outside (table).
– general purpose paint thinner.
– packet of flat wooden stir sticks (knives, paddle pop sticks, etc.)
– plastic disposable yoghurt container (large enough to hold pot lid) for paint thinner.
– glass 20cm tall jar (apple sauce / gherkins) with wide opening and airtight lid to collect ‘dirty’ paint thinner.
– rags.
– paper towels.
– old bucket or cardboard box as portable bin.
– nitrile gloves.
– long sleeves.
– small brush.
– pipe cleaner.
– coffee filter.

Tips
Clean old paint thinner by letting the sludge sink to the bottom of a glass holding jar and pouring the liquid on top through a coffee filter into a new holding container.
Dulux metalshield gloss black / vivid white on galv / painted steel or welds ($40 1L).  Touch dry in 1 hour.
Let paint dry overnight outside (not in shed – fumes).

Safety
Urethane paints are much more toxic than basic oil based enamel paints and require serious precautions.
If you can smell paint your lungs are inhaling paint.  Stop.
Vapour grade 3M paint mask.  Safety glasses.  Paint coverall.
Put your clothes in the washing machine and have a shower afterwards.
[!] Paint in ventilated area.

Painting
Check the weather.  No rain.  No breeze.
[!] Avoid overspray film on nearby objects.  Don’t spray paint your feet.  Don’t have overspray on your (neighbour’s) car.
[!] Prepare a paint station work area outside with cardboard underlayment + test your paint gun stand.
Clean objects to paint with mineral turps and scotch brite (and screwdriver for tight corners).
Hang objects to paint from wire or place on raised pallet wood.
Dilute paint in pot with 10% general purpose paint thinner and stir.
Fan open, air open, trigger adjust open.
Test spray onto cardboard.
Adjust horn 0deg or 90deg for “|” or “—” oriented elliptical spray pattern as desired.
Check water trap.
Set to 35psi when spraying / in use.  Note air pressure will return to max psi tank pressure when in rest.
You get drips when too close / not moving.  Always keep moving even when sometimes it appears no paint is coming out.
You get orange peel ‘dimples’ if you have moisture in your airline.

Cleaning
The paint gun won’t drip paint until you start opening the lid and mess with paint thinner.  So no need for panic / rush.

1. Wear gloves.
2. Disconnect air hose.
3. Paint station work area for cleaning outside (not inside shed).
4. Filter your old thinner liquid sitting on top of the sludge from the holding container into a plastic container using a coffee filter.
5. Empty pot in paint tin.
6. Clean pot and lid with paper towels.
7. Use brush and thinner to clean pot and lid.  Try backpressure trick.
8. Disassemble gun and put parts in thinner.  Careful with spring.
9. Use pipe cleaner and thinner in pot hole.
10. Wipe gun with paper towel and set aside.
12. Clean brush and pipe cleaner and set aside.