Top Tips for Pollution Prevention in Painting and Coatings
- Use dedicated equipment and lines to minimize clean-out between coating changes; reduce the number of
coating changes through techniques like light-to-dark batch sequencing.
- Pre-inspect parts for obvious defects, before painting.
- Reclaim and reuse solvents onsite.
- Flush first with dirty solvent, then fresh solvent.
- Modify the spray booth to allow recovery and reuse of overspray solids.
- Size the paint cup on spray guns appropriately.
- Automate spray and dip operations when possible.
- Isolate spray booths for solvent-based coatings from spray booths for
- Keep solvent soak tanks away from heat sources.
- Use high volume low pressure (HVLP) spray apparatus to increase transfer
- Train employees to use only small amounts of solvents for cleaning.
- Flush equipment first with dirty solvent before final cleaning with
virgin solvent, or pre-clean items with rags before cleaning with solvents.
- Use virgin solvents for final equipment cleaning, then reuse it as paint
- Consolidate solvent cleaning operations and use a multipurpose solvent.
- Reuse cleaning solvents for a resin system by allowing solids to settle
out of solution.
- Use pressurized air mixed with a mist of solvent to clean equipment.
- Keep the wash-off tank covered when it is not in use.
- Minimize dripping by tilting or rotating parts to drain as much solvent
as possible and by allowing sufficient dry time.
- Use rags rather than disposable wipes whenever possible. Launder the
rags in-house or locate a commercial laundry in the area that can provide
- If disposable wipes are used, remove as much solvent from them as
possible before disposing of them. Keep the used wipes and the spent solvent
in separate containers.
- Use low-volume water cleaning systems.
- If possible, return coatings with expired shelf life to the
manufacturer, sell them, or use them as primer.
- Where possible, use coatings that minimize VOC emissions, such as water-borne, powder coatings, UV-cured,
- Use good inventory management methods to reduce waste: rotate stock to avoid out-dated paints; avoid
ordering excess amounts; minimize vendor samples that must be discarded; minimize container waste.
- Where possible, use heat-thinning rather than thinning with solvents.
Spray gun application
- Operator training and experience have been shown to be the biggest factor affecting P2.
- Use the most efficient gun for the specific job (HVLP, electrostatic, etc.).
- Minimize use of stripper.
- Use spent stripper as a rough pre-stripper on the next item.
- Consider the use of the following methods of stripping paint: dry ice
pellets, abrasive media, plastic media bead-blasting, cryogenic, thermal, wheat
starch media, and laser or flash lamp.
- Train spray gun operators in proper spray techniques to minimize generation
of waste coating.
- Pre-inspect parts to ensure they are dry, clean, and dust-free, and to prevent
painting of obvious rejects.
- Schedule coatings to minimize color changes, or paint with lighter colors
before darker colors to minimize the need for equipment cleanouts.
- Mix only as much coating as is needed for a job. Train employees to estimate
amounts and mix paints correctly.
- Save off-color paint for other jobs.
- Apply extra coats to use excess paint.
- Avoid the need for re-coating by first inspecting the area to be painted.
- Segregate non-hazardous paint solids from hazardous paint solvents and
- Segregate solvent waste streams and avoid dilution with water.
- Separate solvents and foreign substances for recycling and reuse.
- Separate thinners from paint sludges by gravity separation and reuse them.
- Use powder coatings to eliminate VOC emissions and obtain high transfer
- Use water-based coating to reduce solvent emissions.
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