Aerospace Dust Collection Systems

Wet Collection vs. Dry Collection for Aerospace Metals

The single most important design decision in aerospace dust collection is wet vs. dry. NFPA 484 draws a hard line based on material reactivity:

• Titanium and magnesium: Wet collection is effectively required. These metals burn at extremely high temperatures, and dry filter media can’t safely contain an ignition event. Titanium dust can also self-ignite through friction or static discharge. Wet collectors eliminate the fuel-air mixture entirely by capturing particles in water.
• Aluminum: Either wet or dry collection is permitted, but dry systems must include full explosion protection — venting panels, chemical isolation, and suppression. Many aerospace shops choose wet collection for aluminum anyway because it simplifies compliance and eliminates explosion protection maintenance.
• Composite materials (carbon fiber, fiberglass): Dry cartridge collectors with HEPA secondary filtration work well. These dusts aren’t combustible metals, but they’re highly abrasive and respirable. Proper filtration protects both workers and sensitive equipment.

Mixed-alloy shops face the trickiest design challenge. If a facility machines both titanium and aluminum on the same production floor, the dust collection system has to handle the most reactive material present. We typically design segregated systems — separate ductwork runs and collectors for each material type — to meet both NFPA 484 and AS9100 contamination requirements.

What NFPA 484 Requires for Aerospace Dust Collection

NFPA 484: Standard for Combustible Metals is the governing code. Here’s what it means for your dust collection system:

• Dust hazard analysis (DHA): Required before any system design. The DHA identifies the combustibility characteristics of your specific dust — Kst values, minimum ignition energy, minimum explosible concentration — and determines the explosion protection strategy. We perform DHAs in-house →
• Equipment design: Collectors must be rated for the specific metal dust. This includes proper material construction (no aluminum collector housings for aluminum dust collection), grounding and bonding to prevent static discharge, and wet collection or explosion protection as appropriate.
• Housekeeping programs: NFPA 484 mandates dust accumulation limits on all surfaces. The collection system has to capture dust at the source effectively enough to prevent accumulation — this drives ductwork velocity, hood design, and capture efficiency requirements.
• Ductwork requirements: Minimum transport velocities to prevent settling (typically 4,000-4,500 FPM for metal dusts), spark-resistant construction, and proper grounding throughout. Flex hose connections at machines must be conductive.

The upcoming NFPA 660 standard (effective January 2026) consolidates several combustible dust codes and will affect aerospace facilities. If you’re planning a new system or major retrofit, designing to NFPA 660 now avoids rework later.

Common Aerospace Dust Collection Applications

CNC titanium machining — 5-axis mills, lathes, and turn-mill centers generating fine titanium dust and chips. Wet collection with pre-separation cyclone for chip recovery. Source capture hoods at each machine with fume extraction arms for operator-accessible areas.

Aluminum wing skin fabrication — Routing, drilling, and trimming of large aluminum panels. High-volume dust generation requiring 10,000+ CFM systems. Explosion-protected dry collection or wet collection depending on facility preference and insurance requirements.

Grinding and deburring — The highest-risk operation. Fine particles, sparks, and heat all present in the dust stream simultaneously. Spark detection and suppression is mandatory. Wet collection is strongly recommended for any combustible metal grinding operation.

Composite trimming and drilling — Carbon fiber and fiberglass dust from trimming cured composite structures. Not a combustible metal hazard, but OSHA PELs for respirable dust still apply. HEPA filtration is standard for composite dust to protect both workers and nearby sensitive equipment like coordinate measuring machines.

Thermal spray and coating removal — Plasma spray, HVOF, and coating strip operations generate metallic fumes and fine particles. Source capture at the booth or enclosure with appropriate filtration based on the specific metals involved.

What an Aerospace Dust Collection System Costs

We’re transparent about pricing because aerospace facility managers need real numbers for capital expenditure planning, not “call for a quote” runaround.

• Single-machine wet collector (titanium/magnesium): $15,000-$35,000 installed
• Multi-machine wet collection system (4-8 stations): $60,000-$150,000 installed
• Explosion-protected baghouse (aluminum, 5,000-20,000 CFM): $45,000-$120,000 installed
• Central system with pre-separation, spark detection, and multiple material zones: $150,000-$400,000+
• DHA testing and engineering: $5,000-$15,000 depending on number of materials and processes

These ranges cover equipment, ductwork, installation, controls, and commissioning for our Southwest service area. The full cost guide breaks down every component. Actual pricing depends on number of machines, facility layout, ceiling height, existing electrical capacity, and which metals you’re machining.

Financing options are available — many aerospace shops spread the cost over 36-60 months while capturing energy and material recovery savings from day one.