A. Airflow, overspray and finish quality
1. The booth fills with visible fog within seconds of spraying
“You start a pass on a full panel and within 30–60 seconds the air is a haze and you lose sight of the surface.”
Why it happens. Fog is atomised paint — droplets roughly 5–50 microns across — suspended because nothing is carrying them to an exhaust fast enough. It is the signature of a single blower doing two jobs: holding the structure up and supplying air, with no dedicated exchange circuit. It settles back onto wet clear as dry spray and solvent pop, which you then sand out or re-spray.
How Sewinfla answers it. Airflow is specified per application rather than fixed. On a 56×25×20 ft booth: dual 950 W blowers at 1,900 CFM total, which meets the OSHA 1910.107(b)(5)(i) reference figure of 100 linear ft/min average velocity over the open face or across the booth cross-section where the air crosses 19 sq ft of open face or less (1,900 ÷ 100 = 19). On our 90 ft pressure vessel booth: eight 706 CFM inflation blowers for 5,648 CFM. The two circuits are separate, so opening a door does not steal pressure from the exchange side.
What to do. Run the exhaust from before the first coat until after the last. Size it to the booth volume: aim for the air in the booth being replaced roughly every 1–3 minutes. If your booth is single-blower, add the exhaust fan — see item 19.
2. Overspray clears only slowly, even with the filters fitted
“Airflow is “pretty good” but mist still hangs for a while after each pass.”
Why it happens. Passive filter windows let air move only as fast as the pressure difference drives it. Without a powered exhaust there is no pressure differential to pull the cloud out; the booth treats filtration as a filter, not as an air-moving system.
How Sewinfla answers it. Filtration is staged for flow, not just capture: two-stage pre-filtration (MERV 8 salt-aerosol plus MERV 11 particulate) ahead of the main carbon media, which is what keeps static pressure low enough for airflow to continue as the filters load. On one marine project this extended main carbon-filter life from about 30 days to about 120 days — roughly $1,400 a year saved — while maintaining flow.
What to do. Add the 12 in / 520 W axial exhaust fan with 16.5 ft duct, or the Air Draft Device for indoor use. Owners who fit them report the fog clearing within roughly a minute of spraying.
3. Dust, debris and insects still land in the finish
“The whole point was a clean space, but specks still appear in the paint.”
Why it happens. Air entering the booth has to come from somewhere. If the intake is unfiltered, or the booth is set up on a dirty surface and the interior was never tacked down, the first shot of the gun lifts that dust into the air — the most common source of nibs is contaminant already inside the booth, not outside it.
How Sewinfla answers it. Every booth uses an isolation chamber: incoming air passes through a separate filtered chamber before entering the work area, and the chamber doubles as a clean place to store paint, PPE and mixed material. Fabric is 210D/201D Oxford with PU coating and double-stitched seams, and the bottom uses thickened abrasion-resistant material to survive parts being dragged in and out.
What to do. Lay a floor tarp on every job (belt loops under each air column are there to hold it), blow and tack the interior before spraying, and wear a spray suit. Test the intake path before you start.