Commercial HVAC Unit Housings — Paint Removal & Powder Coat Prep
A local HVAC contractor brought in eight rooftop unit housings for paint strip and powder coat prep. Panels were 18-gauge steel — too thin for aluminum oxide. We used soda blasting to remove factory paint and surface oxidation without distorting the sheet metal.
Project Photos & Video
Project Details
The Job
An HVAC contractor based out of NE Portland was refurbishing eight rooftop air handler housings for a commercial building project in the Pearl District. The housings were stamped from 18-gauge steel — not the place for aggressive aluminum oxide blasting. The factory paint was chalking and failing, and several of the bottom flanges had rust blistering underneath.
The customer needed them stripped clean without warping the panels, and ready for a polyester powder coat finish.
The Challenge
18-gauge steel is unforgiving. Blast too aggressively and you'll permanently warp panels that are meant to be flat. Most of our rust removal work uses aluminum oxide at 60–80 PSI, but that would have been too aggressive here.
The call: soda blasting.
What We Did
Sodium bicarbonate media at controlled low pressure — 40–55 PSI — strip-cleaned all factory paint, oxidation, and rust blistering without introducing any profile that would telegraph through the final coating. The soda is also water-soluble, so cleanup and environmental disposal is simple.
Media used: Fine-grade sodium bicarbonate Pressure: 40–55 PSI, adjusted panel-by-panel Result: Zero panel distortion, zero warping — verified with a straight edge
Surface Profile Note
Soda blasting creates a near-white surface (SSPC-SP6) but does not create an anchor profile. We communicated this clearly to the powder coater: the coating applied was a thin phosphate etch primer first, then polyester powder — the correct sequence for soda-blasted steel.
Results
- 8 panels stripped clean, no warping or distortion
- Rust blistering fully eliminated on all flanges
- Delivered to powder coater within 4 hours of completion (same-day coordination)
Turnaround
Job completed over two days (4 panels per day). Customer picked up on Day 3 and delivered directly to their coater.
Takeaway
Not every job calls for the same media. We've been doing this long enough to know the difference. If your parts are thin-gauge, aluminum, or otherwise sensitive — tell us. We'll choose the right media for the job and deliver results your coater can actually work with.