HVLP Spray Gun

identity

Name: the HVLP spray gun, High-Volume, Low-Pressure spray gun. A finish-application tool that atomizes a compatible liquid coating into a controlled fan pattern using a large volume of air at low dynamic pressure at the air cap. It is designed to reduce particle velocity, bounceback and overspray, and can improve transfer efficiency relative to conventional air spray when properly selected, set up and operated [HV6][HV11].
Regional / alternate names: paint spray gun, finish spray gun, touch-up spray gun (general spray-gun family). Within HVLP, "conversion gun" (compressor-fed) and "turbine gun" (dedicated-motor-fed) are functional names, not regional ones [HV3].
Family / category: Finishing application tools. Sits alongside shop infrastructure (compressors) as a tool that consumes compressed air when compressor-fed, per this corpus's Air Compressor entry [HV1].
One line: HVLP names an air-atomization regime. Gravity, suction and pressure name how fluid reaches the gun. They are separate axes, and any of the three feed modes can be built around HVLP air [HV2][HV6].

Definition, and whose it is. In South Coast AQMD's current Rule 1151 (automotive and mobile-equipment coating, within that district), HVLP is equipment that atomizes 100 percent by air pressure, operating at 0.1 to 10 psig measured dynamically at the air cap and horns [HV12]. Other jurisdictions and uses have their own definitions. It is not a woodworking regulation.

✦ how NOT to use it

not-for: coatings your ventilation, ignition control and respiratory protection do not cover; two-component or isocyanate coatings without the controls below; any gun on an air supply that cannot sustain its demand.

dangerous: HVLP's lower atomizing pressure does not remove spray-finishing hazards. It does not eliminate fire, explosion, toxic inhalation, eye and skin exposure, sensitization, environmental release or pressurized-vessel hazards. Lower overspray does not mean safe exposure. This section replaces the earlier "genuinely thin" entry, which was a research result presented as a risk assessment.

• Read the SDS and TDS first. They set flammability, toxicity, permitted reducer, pot life, ventilation and PPE, and waste handling.
• A compliant spray area is not "a well-ventilated space." OSHA 29 CFR 1910.107, read directly, requires mechanical ventilation in spraying areas that removes flammable vapors, mists or powders to a safe location, run during spraying and long enough afterward to clear vapors from drying articles and residue; exhaust ducts discharge outdoors and are not recirculated; booth and duct metal and piping carrying flammable liquid are grounded [HV17]. OSHA 1910.94 also governs ventilation for covered spray finishing (not read here; per the reviewer) [manual, relayed] [HV18]. Whether those rules apply to a given shop, and what local fire, environmental and occupational rules add, is the user's to determine. Local rules may be stricter.
• Control ignition sources. 1910.107 as read: no open flames or spark-producing equipment in a spraying area or within 20 ft of it unless partitioned; electrical equipment in or near the area must meet the hazardous-location class the standard names; portable electric lamps are not used during spraying; no smoking, with signs posted [HV17]. Never put a non-rated turbine, heater, pilot flame or other ignition source in a hazardous spray atmosphere.
• Turbine motors can spark. The review reports a current Graco HVLP manual warning that the turbine motor generates sparks and must be kept at least 20 ft (6 m) from the spray area for that system [manual, relayed] [HV19]. Another gun's manual summary gives 15 ft, partly to keep overspray out of the filters [manual, relayed] [HV15]. Follow the manual for your exact turbine and hose.
• Residue, filters, solvent and rags. 1910.107 as read: keep spraying areas free of combustible residue and clean with nonsparking tools; put finish-soaked rags in approved metal waste cans emptied at least daily; move used filter pads to a safe detached location or keep them in a water-filled metal container; use cleaning solvents with a flashpoint of at least 100 F; clean booths with ventilation running [HV17]. Dual-component organic-peroxide coatings may only be sprayed in approved, sprinklered spray booths that meet the section [HV17].
• Grounding, wetted materials, hoses. Follow the system and coating instructions on grounding or bonding, wetted-material compatibility, pressure limits, hose inspection and safe solvent cleaning.
• Pressurized cups and pots. Isolate air and power, and relieve fluid pressure, before opening a cup or pot, clearing a clog, removing a nozzle or servicing. Do not point the gun or a leak at a person.
• Airless is its own injection hazard. Very high fluid pressure can inject coating through skin; that hazard belongs mainly to airless systems and pressurized lines [HV10]. It does not make pressure-pot or hose hazards on HVLP zero.

Isocyanates and other sensitizers (high-control, specialist work). Many two-component coatings are not isocyanate coatings, but some are, and "catalyzed" does not tell you which. NIOSH Health Hazard Evaluation 82-359, read directly, documents spray painters using an MDI-containing coating: 11 of 14 had burning eyes each time they painted, 8 of 14 had shortness of breath, and 4 of 14 had fever, chills, wheezing, shortness of breath and chest pain four to eight hours after use, which several physicians took for the flu. Isocyanates give no odor warning, and symptoms occurred even with half-face charcoal-filter respirators. NIOSH recommended supplied-air respirators for spraying isocyanate paints [HV20]. Therefore:

• Coating chemistry governs suitability and PPE. Respirator choice cannot be inferred from the word "HVLP" or from odor.
• Require the current SDS and TDS, an exposure assessment where applicable, compatible gloves and eye and skin protection, and a compliant respiratory-protection program (selection, medical evaluation, fit testing, training, maintenance, and approved air supply). NIOSH names a respirator program consistent with 29 CFR 1910.134, approved components only, and a supplied-air source that meets air-quality specifications [HV20].
• Isocyanate-containing spray coatings are specialist work. Do not recommend them to a general maker without the engineered controls and respiratory protection above. This entry cannot select a respirator for you.
• Wear solvent-impervious gloves of sufficient length when cleaning spray equipment; NIOSH noted this was neglected [HV20].

damaging: a tip, needle and cap set that does not suit the coating's viscosity, giving poor atomization or a failed finish [HV7]; thinning outside the coating maker's instructions; inadequate or delayed cleaning, which lets finish dry in fluid passages and clog the cap or wear the needle (corroborated across retailer and how-to sources, not tied to one primary account); an undersized air supply, which causes pressure drop and poor atomization.

beginner-trap: holding the gun at a distance that is not your gun's (very long distances are named as poor in the Woodweb accounts) [HV8]; treating a fan problem as a thinning problem; assuming pressure, tip or transfer behavior carries over from conventional or airless guns; trusting compressor tank size as capacity; applying the pressure-pot setup to a gravity cup.

lineage-misuse: one Woodweb contributor says banding is not a problem they have had with compressed or turbine HVLP but have seen with airless, which is one person's experience that the technologies do not behave identically [HV8]. Feeding a conversion gun from a small compressor sized for finish nailing is the same misuse this corpus's Air Compressor documents from the compressor side [HV1].

correct use

Start from the paperwork, not the gun. Read the coating's safety data sheet (SDS) and technical data sheet (TDS) first. They state the permitted application method, reduction, viscosity, film build, flash and recoat times, ventilation, PPE and waste handling. Then read the gun manual for the matched needle, nozzle and air-cap set, inlet pressure, air demand, hose and filtration, cup or pot limits and cleaning method. Where the two disagree, stop and ask, not guess.

General setup (all HVLP guns). Use the gun manufacturer's matched fluid set and the coating's TDS and SDS. Account for measured viscosity, temperature, feed system, required film build and the reducer the coating maker permits. Start at the maker's recommended inlet or turbine setting with the trigger flowing, use the lowest setting that gives the required atomization, and adjust fluid and fan on a scrap panel in the order the gun's manual prescribes. A summary of the Fuji T-Model manual gives the order thin the coating, set the pattern, set fluid flow, adjust air last, with a Ford #4 cup used to check viscosity and thinning kept to the minimum and to the solvent the can lists. That is one gun's sequence, not a universal one [manual, relayed] [HV15]. Change only within both manufacturers' instructions. Unauthorized thinning can give a poor cure, illegal VOC content, extra vapor load, equipment damage or a failed finish.

Tip, needle and cap. Choose from the matched set by the coating's data. A Fuji T-Model summary lists nozzle sizes from 0.8 mm up, with 1.3 mm called standard and 1.0 to 1.5 mm used for fine finishing; the same summary lists larger sizes for thicker coatings [manual, relayed] [HV15]. No one size is correct for "wood lacquer." The Woodweb accounts above are single-shop experience.

Pressure-pot guns only. The Woodweb thread on adjusting pressure and fan patterns concerns guns equipped with a remote pressure pot. Its method (set the fluid pressure to give a straight unatomized stream of about 6 to 8 inches, then reintroduce air) adjusts the pot's fluid pressure. The review says it does not apply to a gravity or suction cup and that a fan pattern cannot be judged with the atomizing air off [manual, relayed] [HV8]. If you use a pressurized pot, relieve its pressure before opening it, even at low atomizing pressure.

Technique. Test on scrap. Hold the gun perpendicular to the surface and move at a steady speed with controlled overlap; going too slowly or overlapping too much is named as a cause of runs and sags [HV7]. Distance is a number for your gun, from its manual. The 6 to 8 inch figure in the Woodweb accounts and an 8 inch maximum in the Fuji manual summary are single-model or single-shop numbers, not a rule [HV8][HV15].

✦ matching, the workbench's first read

Does: uses high-volume, low-pressure atomizing air at the cap to turn a compatible liquid coating into a controlled spray pattern. Whether a given coating is compatible is decided by that coating's TDS, not by its category name.

Match by this order.

• The coating's TDS and SDS: permitted application method, reduction and film build, hazards.
• Chemistry: isocyanate-containing and other sensitizing coatings are specialist work (see how NOT to use it) and are not offered here to a general maker. "Catalyzed coating" is not one material class. "Water-based" does not mean non-toxic or noncombustible in every formulation.
• Project scale and geometry, required finish quality and output rate.
• Controls available: ventilation, ignition control, PPE and cleanup. Emissions and fire rules where the work is.
• Air supply and the gun's actual demand (the compressor gate below).

Suits: fine-finish work where the coating's TDS permits HVLP and the shop has the air supply, ventilation, environmental controls, PPE and cleanup capability. Pressure-fed HVLP is production-capable where the equipment and coating specify it.

Compressor compatibility gate. There is no safe default pairing with "a shop air compressor." Match the gun's published continuous air consumption at its required dynamic inlet pressure to the compressor's delivered CFM at that pressure, with margin for duty cycle. Tank size alone is not capacity. Also check hose and fitting size, regulation and filtration, and condensate, oil and moisture control. As examples the review consulted, a DeVilbiss FLG4 manual lists 13 cfm for its HVLP air cap and a SATA HVLP model about 15 cfm at a stated inlet pressure [manual, relayed] [HV16]. These are two models, not a rule. An undersized supply gives pressure drop and poor atomization. Never feed respiratory protection from ordinary shop compressed air unless the complete approved breathing-air system meets the applicable requirements. This replaces the earlier claim that this entry closed the Air Compressor entry's CFM gap. It does not; the needed data is each gun's own.

Kit-fit:

• Pairs with: a compressor or turbine that meets the gate above, a compliant spray area (see below), and the PPE the SDS requires.
• Alternatives, by application mode: brush, roller, pad or wipe, airbrush, aerosol, conventional air spray, LVLP, airless, air-assisted airless, electrostatic, dip, flow coat. Some stains are wiped on, not left as an atomized film, so "stain" is not a blanket fit.
• Not a replacement for a brush or rag on small touch-ups where setup and cleanup cost more than the job (reasoned from the mechanism, not sourced).

Not-for: a coating the gun is chemically incompatible with; a coating that cannot be reduced or atomized within its TDS; any location lacking the required exposure, fire and environmental controls; a compressor or turbine unable to sustain the gun's published demand.

Access: moderate barrier. Setup (matched set, viscosity, pattern and distance) is learned on scrap. The larger barrier is the controls: a compliant spray area, ignition control and respiratory protection.

anatomy

The gun body and trigger. Many air-spray guns use a two-stage trigger, first air and then fluid. That is typical of manual air-spray guns, and each model's manual governs. The fluid nozzle (tip), needle and air cap are normally a matched set. The tip diameter alone does not decide suitability; the set must suit the coating and the gun [HV7]. The air cap surrounds the fluid nozzle, shapes the fan, and on most caps has adjustable horns. The cup or pot delivers the coating. The air source is a compressor or a dedicated turbine.

Feed modes, defined mechanically.

• Siphon or suction feed: the cup is below the gun and airflow draws fluid up.
• Gravity feed: the cup is above the gun and fluid flows down.
• Pressure feed: a separate pressurized cup or pot delivers fluid to the gun.

Orientation limits, leakage limits, cleanup, capacity and transfer performance depend on the cup, liner and vent design and on the manufacturer's instructions, not on the feed label alone. A summary of the Fuji T-Model manual says its gun may be angled but not turned past horizontal [manual, relayed] [HV15]. Do not assume another gun can be tilted, laid flat or inverted.

Four pressures, which are not the same number. Do not swap them:

• Turbine outlet pressure, the source of the air supply.
• Gun-inlet pressure with the trigger flowing, which is what most manuals specify.
• Remote-pot fluid pressure, for pressure-fed setups.
• Dynamic air-cap pressure, which is what the regulatory definition measures.

Hose and gun losses separate them, and South Coast AQMD specifically relies on inlet-to-cap correlation or a tip gauge [HV12]. A compressor-fed gun may need a higher inlet pressure while still operating at or below 10 psig at the cap. A turbine's stage count is not a performance specification. Give numbers only per model.

Air source. Turbine and conversion (compressor-fed) systems are alternate air sources used in different markets. No source read here establishes turbine systems as a general professional standard. A conversion gun is designed for a specified air volume and dynamic inlet pressure; the regulator, hose, fittings and internal passages together determine cap performance.

variations (living)

• Gravity-, suction- and pressure-fed HVLP guns, as defined under anatomy. Performance and orientation are model-specific.
• Compressor-fed (conversion) HVLP, which needs a compressor that meets the gate under matching.
• Turbine HVLP, which has its own motor and air. Turbine motors can produce sparks, so placement rules apply (see how NOT to use it).
• Pressure-fed HVLP is used in production, and is not limited to hobby use. Suitability depends on coating, film build, line speed and finish requirement [HV2].

trades

Furniture and cabinet finishing is the trade this entry serves, and the source of nearly all its technique accounts [HV7][HV8][HV9]. Automotive refinishing is where the regulatory definition above originates and where much of the vocabulary comes from [HV3][HV12]. General painting and decorating commonly uses conventional and airless guns for higher-volume work; where HVLP fits depends on the coating, film build and finish requirement, not on a fixed rule [HV2].

lineage

Ancestors. Dates here are attributed to their sources and are not independent chronology.

• Francis Edgar Stanley is documented by the Smithsonian's Lemelson Center as patenting a liquid-color atomizer in 1876 (for applying color to photographs), with later airbrush development including an 1881 color-atomizer patent. This is an earlier documented spray ancestor than the 1888 DeVilbiss work [manual, relayed] [HV13].
• Allen DeVilbiss (1840 to 1917), a Toledo physician, built a medical throat atomizer from a rubber bulb and tubing. The Smithsonian's DeVilbiss Atomizer No. 15 record supports the firm's 1888 founding and its later move into paint spray guns under his son Thomas. The object record points to 1909 patents; it does not by itself date a first paint gun [manual, relayed] [HV4]. The patent number the earlier draft listed ("US 035,094") is not a complete patent identifier and is dropped. The review points to US 378,357 for Allen DeVilbiss's 1888 patent; that has not been read here and should be verified before it is published.
• The working principle (air crossing a pickup tube lowers pressure and draws liquid up) is the one a siphon-feed gun still uses [HV4].
• Thomas A. DeVilbiss is credited by trade press with a hand-held air-powered paint spray gun in 1907, and Joseph Binks with a pressurized cold-water paint-spraying machine in 1887 and hand-held compressed-air guns around 1919 to 1920. Both are company or trade-press "first" claims and are attributed, not confirmed by patents or archives read here [HV2][HV4][HV5].

HVLP itself. Bob Flexner's 2011 retrospective traces turbine HVLP through a chain from a vacuum-cleaner spray attachment, to Simco, Volumaire and Apollo Sprayers. That chain was not established from primary records in this review, and it is Flexner's account, not settled fact [HV3].

Contemporaries and alternatives by mechanism.

• Conventional air spray atomizes with higher air-cap pressure.
• Airless spraying atomizes the coating hydraulically, at very high fluid pressure through a small orifice, with no atomizing air. It is a different mechanism, not a scaled-up pressure-feed HVLP gun, and no descent between the two is asserted here. EPA's technical overview, as relayed by the reviewer, gives airless pressures of roughly 400 to 4,500 psi [manual, relayed] [HV14]. A pressure-fed HVLP gun still uses air at the cap to atomize coating delivered from a remote pot.
• LVLP, air-assisted airless and electrostatic guns are further separate systems.

history

• General spray-gun origin. DeVilbiss and Binks each drew on atomizing or pressure-vessel ideas, arriving at hand-held compressed-air guns around 1919 to 1920 per trade press [HV2][HV5]. The widely repeated 1924 Oakland and Duco cycle-time story was not established here from primary records and is not carried as fact.
• HVLP and Rule 1151, kept apart.
  • Anecdote, secondary source. Flexner reports that Apollo Sprayers submitted independent transfer-efficiency testing to South Coast AQMD in 1984 and that the district coined the term. Primary documentation for this was not located in this review [HV3].
  • Regulation, primary source. Rule 1151 was adopted July 8, 1988 and was most recently amended November 1, 2024. The current text defines HVLP by dynamic air-cap pressure (0.1 to 10 psig) and defines transfer efficiency as coating solids deposited divided by coating solids sprayed [HV12]. The reviewer reports that the rule requires HVLP or an approved equivalent or better-transfer method for covered automotive work, and does not state a universal 65 percent threshold [manual, relayed]. The earlier draft's "around 1986" requirement and 65 percent threshold are withdrawn. Do not back-project the current wording to 1984.
• No single foundational HVLP patent was located. The technology diffused through several makers, and that absence is stated rather than papered over [HV3].

✦ human side

The people this tool belongs to. Furniture and cabinet finishers spraying coatings that suit it, one-person shops that already own a suitable air source, and automotive refinishers, where the regulatory definition above originates.

Practitioner accounts, treated as pseudonymous forum posts. Contributors on Woodweb and Garage Journal are known by handles or initials and are not independently verified. They give single-shop experience, not standards.

• On Woodweb's "HVLP Tip Size" thread (2006), a contributor identified as "W" says they usually do not recommend a 1.4 tip set for their wood lacquer work and prefer 1.7 or 1.8 mm, and another contributor ("L") describes a 1.7 mm tip with a 1.9 mm cap and lacquer thinned 7 percent [HV7]. The review notes that another Woodweb discussion reports good results with 1.3 mm and stresses that gun, feed type, viscosity, temperature and coating all matter [manual, relayed]. This is one discussion of particular lacquers and guns. It is not a woodworking standard.
• On Garage Journal's "Mini HVLP tip size" thread (2024), the user dnschmidt reports preferring a 1.0 mm tip for most things and a 1.2 mm for thinned primer and epoxy [HV9]. That is that user's choice on those mini guns.
• Woodweb's "Adjusting Pressure and Fan Patterns for HVLP Sprayguns" thread (2005) concerns pressure-pot-equipped guns; see correct use for what it does and does not support [HV8].

Honest gap. Specific technique quotes from Flexner, Jewitt, Neil and Spagnuolo could not be fetched and verified, and none is included as a sourced claim.

✦ proof of existence

Earlier documented ancestor technology. Stanley's 1876 liquid-color atomizer patent, documented by the Smithsonian Lemelson Center [manual, relayed] [HV13]. DeVilbiss's medical-atomizer line is documented in the Smithsonian NMAH record, which supports the company's 1888 founding, not a first spray device [HV4].

Purpose-built paint guns. Thomas DeVilbiss's 1907 gun and Binks's 1887 machine are trade-press claims, not patent- or museum-tier evidence [HV2][HV5].

Regulatory record for HVLP. Rule 1151 (adopted July 8, 1988; amended November 1, 2024) is the primary, read-directly source for the 0.1 to 10 psig dynamic air-cap definition [HV12]. The 1984 test-and-coining account remains Flexner's [HV3].

Museum records. DeVilbiss's medical atomizers are in the Smithsonian NMAH collection. No museum record for a finish spray gun was located. Patents: none was read directly in this review.

references

• [HV1] Air Compressor (this corpus). The spray gun appears in its origin, matching and misuse blocks. It had flagged a CFM gap; the gap is not closed by this entry.
• [HV2] BodyShop Business, "The History of Sprayguns" (Mark Clark), bodyshopbusiness.com/the-history-of-sprayguns/. Trade press; typology and "first" claims are attributed.
• [HV3] Bob Flexner, "HVLP's evolution is an interesting story," Woodshop News, Nov. 14, 2011, woodshopnews.com/columns-blogs/hvlps-evolution-is-an-interesting-story. Secondary account; primary documentation not located.
• [HV4] Smithsonian NMAH, DeVilbiss Atomizer No. 15. Supports the firm's 1888 founding and later move to paint guns. Relayed via the reviewer.
• [HV5] BodyShop Business (above); FundingUniverse, "History of Binks Sames Corporation," fundinguniverse.com/company-histories/binks-sames-corporation-history/. Company history.
• [HV6] Synthesis of HV2 and HV12 (air-atomization regime versus feed mode). Not an independent source.
• [HV7] Woodweb, HVLP Tip Size (Nov 11, 2006). Pseudonymous contributors; one lacquer and gun discussion, not a standard.
• [HV8] Woodweb, Adjusting Pressure and Fan Patterns for HVLP Sprayguns (Dec 31, 2005). Concerns pressure-pot-equipped guns.
• [HV9] Garage Journal, "Mini HVLP tip size" thread (Jul 2024), garagejournal.com/forum/threads/mini-hvlp-tip-size.535017/. One user's choices.
• [HV10] Wikipedia, "High pressure injection injury"; toolguyd.com. Secondary tier; identifies airless as the dominant injection-injury source.
• [HV11] EPA, Preferred and Alternative Methods for Estimating Air Emissions from Surface Coating Operations, Vol. II, Ch. 7. Not read here; the reviewer reports it supports compressor or turbine air supply, reduced bounce, possible transfer-efficiency improvement, and that transfer efficiency varies with geometry, gun, velocity, operator and booth air.
• [HV12] South Coast AQMD Rule 1151. Read directly in this pass: adoption July 8, 1988; amended Nov 1, 2024; HVLP definition; transfer-efficiency definition.
• [HV13] Smithsonian Lemelson Center, "How the Invention of the Air Brush Transformed Commercial Art". Not read here; relayed via the reviewer.
• [HV14] EPA Vol. II, Ch. 7 (see HV11) for airless pressure range. Relayed via the reviewer.
• [HV15] Fuji Spray T-Model manual. Read in this pass through a fetch summary, not the full text; one model's rules.
• [HV16] DeVilbiss FLG4 gravity-feed service manual. Not read here; the 13 cfm figure is relayed via the reviewer. SATA figure also relayed via the reviewer.
• [HV17] OSHA 29 CFR 1910.107, Spray finishing using flammable and combustible materials. Read in this pass (via a fetch summary).
• [HV18] OSHA 29 CFR 1910.94, Ventilation. Not read here; relayed via the reviewer.
• [HV19] Graco FinishPro HVLP manual 3A5085EN-D. Fetch refused in this pass; relayed via the reviewer.
• [HV20] NIOSH Health Hazard Evaluation 82-359-1382. Read in this pass (via a fetch summary).

The reviewer's corrections (13)

• BLOCKER — 1. — Exact claim: “dangerous: genuinely thin” and “Solvent-load and flammability risk … is carried here only as a generic, unattributed caution.”
• BLOCKER — 2. — Exact claim: “Does: atomizes … catalyzed coating” and “Pairs with: … a spray booth or well-ventilated space.”
• BLOCKER — 3. — Exact claim: “the named Woodweb consensus rejects automotive-sized 1.4mm tips for standard wood lacquer in favor of 1.7–1.8mm” and “an undersized tip … [is] a cause … rather than a material problem to fix by thinning further.”
• BLOCKER — 4. — Exact claim: “Set the fan pattern and air pressure with the atomizing air off first, dialing the fluid stream to a straight 6"–8" pattern before reintroducing air.”
• BLOCKER — 5. — Exact claim: “Pairs with: a shop air compressor” and the status claim that the entry “closes the Air Compressor entry's … CFM gap.”
• SHOULD-FIX — 6. — Exact claim: “in 1984 … SCAQMD coined the term … Around 1986, SCAQMD began requiring HVLP or equivalent (≥65% transfer-efficiency) equipment, tied to Rule 1151.”
• SHOULD-FIX — 7. — Exact claim: HVLP provides “much higher transfer efficiency” and deposits “a much higher percentage … than a conventional high-pressure gun.”
• SHOULD-FIX — 8. — Exact claim: “Earliest confirmed dated example of the ancestor technology: Allen DeVilbiss's medical atomizer, patented and manufactured from 1888.”
• SHOULD-FIX — 9. — Exact claim: “Airless spraying … is pressure-feed scaled to a very high level”; it appears under “Descendants,” then is called “a contemporary, not a descendant.”
• SHOULD-FIX — 10. — Exact claim: “Siphon-feed … lower transfer efficiency than gravity-feed because material gets caught in swirling air ahead of the cap”; “gravity-feed … cannot be laid flat”; “pressure-feed … can be used inverted.”
• SHOULD-FIX — 11. — Exact claim: “Turbine HVLP … the professional-refinish standard”; “each stage adding roughly 2 psi, a typical 5-stage turbine reaching about 10 psi at the cap”; and conversion guns are “stepped down internally.”
• SHOULD-FIX — 12. — Exact claim: “Not-for … continuous heavy-build production spraying, where a conventional or airless setup's higher output may suit better” and a binary brush-versus-HVLP framing.
• MINOR — 13. — Exact claim: “well-sourced, multi-name origin story,” “every named technique source,” patent-fetch process notes, and the provenance account of research passes.