# Air Compressor Hewn Tool Library ยท https://hewn.build/tools/air-compressor Corrected: An independent reviewer read this entry and found corrections. They have been applied to the text, and the reviewer re-checked the correction that mattered most for safety and found it done; the others have not been re-checked yet. The list at the end is the record of what changed. Cite as: "Air Compressor." Hewn Tool Library, hewn.build/tools/air-compressor. Reviewed 2026-07-31. --- ## identity **Name:** Air compressor, portable shop class: pancake, hot dog, twin-stack, wheelbarrow. **Scope:** this entry covers portable electric shop units. Stationary two-stage machines, gasoline-driven wheelbarrow units, battery units, tankless inflators, high-pressure construction compressors and breathing-air systems are not governed by its claims; each needs its own manual and checks. Gasoline units add fuel, exhaust, carbon monoxide, hot-engine and outdoor-use controls that this entry does not give. **Family:** Shop infrastructure, pneumatic power supply. Not a cutting tool. A motor-driven pump, controls and (usually) a pressure-rated receiver tank that stores air for tools to draw. **One line:** A motor, a pump and a pressure vessel on a handle. It stores work done now so a tool can spend it later, and the stored pressure is both the point and the hazard. --- ## how NOT to use it ### Not-for - **Breathing air from ordinary shop compressor air** (above). - **Tools whose air data the compressor cannot meet.** Check the tool maker's consumption and duty pattern. - **Spray finishing or blow-cleaning without the gates above.** - **Cleaning people or clothing with a blowgun.** ### Dangerous - **Running a corroded tank until it fails.** CPSC Recall 02-108 (February 26, 2002): 458,000 Ingersoll-Rand portable compressors sold 1983 to 1991, up to 30-gallon tanks, nine brand names. "Internal corrosion to the inner wall of the air receiver tank can cause the air tank to unexpectedly rupture allowing pressurized air to suddenly and forcefully escape." 11 reports of sudden tank failure, no injuries reported at recall (per the reviewer; the original pass read the notice directly). The notice says tanks do not have infinite life, and that life depends on operating conditions, installation, modification and maintenance (per the reviewer). Exterior appearance cannot rule out internal corrosion. No universal retirement interval is claimed here: recalls and manufacturer retirement and replacement instructions control. - **Welding, drilling or modifying a tank.** The Campbell Hausfeld example manual: "Never attempt to repair or modify a tank! Welding, drilling or any other modification will weaken the tank resulting in damage from rupture or explosion." Never repair a leaking, corroded or damaged tank. Check the exact manual for what yours says. - **Defeating or ignoring the safety valve and pressure switch.** Practitioners in the Garage Journal thread report overpressure from a failed shutoff or relief valve as one route to failure. Anecdote, not a finding. - **Working on or changing attachments with the machine energized or pressurized.** Switch off, unplug and bleed first. - **Electrical misuse.** Ungrounded circuits, wrong voltage, wet locations, damaged cords. Follow the manual. - **Hose and fitting misuse.** Overpressure of the weakest part, uncontrolled hose at connection, damaged hose. - **Touching the hot head or discharge tube; running with guards off.** - **Flammable vapor near the compressor** (see spray gate). - **Blowgun against skin or clothing.** ### Damaging - **Not draining the tank per the manual.** Moisture collects and the corrosion is internal. Practitioner end-state (wazzabie): drain after every session, leave the valve open in storage. - **Wrong oil practice.** Oil-lubricated pumps need the manual's oil level and type; oil-free pumps take no oil. The MAC2400 has a sight glass per the reviewer's source notes. - **Wet air downstream.** Water travels up the hose into nailers and spray guns. A filter or trap addresses finish quality and tool wear. (Mechanism follows from the condensation story; no dedicated finishing-failure source was fetched.) - **Duty cycle.** Running the pump against more demand than it can supply. Duty-cycle figures for specific models were not sourced; check the manual. ### Beginner-trap - **Buying by one label number.** Peak horsepower and tank gallons are not the whole story. See the settlement and *matching*. - **Running everything at maximum pressure.** The regulator exists so each tool sees its own working pressure. Tool-specific pressure specs were not fetched. - **Assuming "air tool" is one category.** Check each tool's pressure and consumption. - **Unopened drain valve.** Nothing happens for years, then structure is compromised. Follow the manual. ### Lineage-misuse - **Expecting the hand-carry unit to do a stationary machine's job.** Same family, different duty. Check the exact tool's demand. - **Treating the receiver tank as ordinary steel.** It is a rated pressure vessel; patching a tank that has announced its corrosion does not fix the thinning around it (the Garage Journal case). - **Treating the compressor like a tankless inflator.** An inflator has no receiver; a compressor left with an undrained, pressurized tank inherits the corrosion story. - **Treating the pump like an on-demand supply**, as a cordless nailer is. Stored air has a delivery ceiling and recovery time. --- ## correct use *(brief, the workbench holds deep operation)* - **Follow the model manual for the drain.** Condensate collects in the tank, and the Campbell Hausfeld example manual (doc. 254702, a different model) says "Drain liquid from tank daily" and "Tanks rust from moisture build-up, which weakens the tank." Use the exact interval and sequence from your own manual; the MAC2400 intervals could not be checked here. - **Check the safety valve per your manual.** Per the reviewer, the MAC2400 manual says to pull the ring "occasionally" and replace a stuck valve with the same type. The Campbell Hausfeld example says daily; that does not carry over. Practitioners in the Garage Journal thread suggest at least annually; that is opinion. - **Set the regulator to the working pressure of the tool and every other component**, not the tank maximum. - **If the compressor will not stop running, shut it off and find out why.** - **Match the exact tool to the compressor** as described in *matching*. - **Check recalls** by exact brand, model and serial data. --- ## matching *(the workbench's first read)* **does:** stores compressed air and delivers it at a regulated pressure. Works intermittent pneumatic tools (brad, finish and framing nailers, staplers, pinners) within the limits below. Inflates tires and inflatables, slowly, with an independent gauge and the object maker's pressure value. Powers other tools only where the tool maker's air data fit the compressor's delivered air. **How to match (the reviewer's wording, kept):** compare the compressor's delivered SCFM at the pressure the exact tool requires with the tool maker's consumption and duty pattern, allowing margin and line losses; then check the compressor's duty cycle and its tank and recovery behavior. Tank volume does affect burst duration and cycling; pump delivery and duty cycle determine sustained capability. Neither alone decides it. 90 PSI is a common rating point, not the right comparison pressure for every tool. Also confirm maximum pressure, hose and fitting pressure drop, electrical supply and acceptable run time. Do not silently swap SCFM, ACFM, CFM and displacement; keep the pressure point with the figure. **The Makita MAC2400 figures (per the reviewer's source notes, from Makita's page and manual; not opened here):** 4.2 gallon twin-stack tank, 4.2 CFM at 90 PSI, 4.8 CFM at 40 PSI, 130 PSI maximum pressure, 1,730 RPM, oil-lubricated pump, 79 dB. **Matches, split by what the data supports.** The matcher should store, for each tool, its pressure, average and peak consumption, duty pattern and any air-quality requirement, and sort into `capable for short bursts`, `supports sustained use`, or `not manufacturer-supported`. No spray-gun, DA sander, die grinder or blasting demand figures were fetched, so none are asserted and no whole tool family is excluded or included without the exact tool's data. Short-burst intermittent tools such as finish nailers are the usual fit; the tool maker's data decides. **Gated match 1: spray finishing.** Spraying is conditional on all of these: - The coating's label and SDS, local ventilation and fire rules, the spray equipment manual and the compressor manual. - **Ignition.** Motor and pressure-switch contacts can spark. Per a search summary of the MAC2400 manual (not opened here): never operate in an atmosphere with flammable vapors, do not operate in the paint spray area, and when spraying flammable materials locate the compressor at least 20 feet from the spray area. Per the reviewer, the manual also requires cross-ventilation, label and SDS compliance, and an application-specific approved respirator. - **A filter or water trap is for finish quality, not operator breathing protection and not ignition control.** Dry, clean air is not the complete safety setup. - **Breathing.** Ordinary compressor air is not breathing air (see below). Where those cannot be met, the match fails. A dedicated spray gun's own air consumption must be checked against delivered SCFM at its pressure. An HVLP turbine or airless rig may suit serious finishing; the matcher should compare on the exact equipment. **Gated match 2: compressed-air cleaning (blowgun).** This is a conditional match, not a routine "dust-off." - OSHA 29 CFR 1910.242(b) is a workplace rule for cleaning with compressed air. Text confirmed by search summary only (osha.gov blocked here): compressed air is not to be used for cleaning except where reduced to less than 30 psi, and only with effective chip guarding and personal protective equipment. - OSHA directive STD 01-13-001 (search summary): the rule means the downstream pressure at the nozzle or opening stays below 30 psi under static conditions; when dead-ended, static pressure at the main orifice must not exceed 30 psi. A regulator set at 30 psi does not by itself prove the nozzle or the operation complies. Per the reviewer, higher dynamic pressure can comply where a properly designed relief nozzle meets the dead-end condition. - "Effective chip guarding" (same directive, search summary) means any method or equipment that prevents a chip or particle from being blown into the eyes or unbroken skin of the operator or other workers. Protective cone nozzles are generally acceptable for the operator, but barriers, baffles or screens may be needed for others. - Use a safety nozzle, chip guarding or barriers, eye and face protection as indicated, and keep bystanders out. - Never clean your body, clothing or anyone else with compressed air. Basis: OSHA interpretation letter dated 1994-01-14, as described in the reviewer's source notes (page not opened here). - Where blowing would spread fine wood dust, coating, silica, metal, lead or other hazardous dust, prefer capture and vacuuming and assess dust-specific respiratory protection and housekeeping. This is a safe-method judgment per the review, not a sourced figure. - Whether this applies in a home shop is a jurisdiction question. It is an occupational rule; the hazards remain regardless. **Not breathing air.** The manufacturer warning, as quoted from the Campbell Hausfeld example manual (a different model; model manuals say the same in kind): "This compressor/pump is NOT equipped and should NOT be used 'as is' to supply breathing quality air." the review states shop compressors are not breathing-air systems. Do not supply a respirator from ordinary shop compressor air. **kit-fit.** **Pairs with:** nailers and staplers, hose and quick-connects, inline filter and regulator, water trap or dryer for finish quality, tire chuck. **Substitutes for:** task-specific only. A compressor with pneumatic guns versus cordless or fuel-cell nailers depends on tool count, hose handling, weight and total system cost (hose, fittings, filters, maintenance). A 12V inflator may be preferable for vehicle portability, weight and emergency power. **Cannot replace:** a stationary compressor for high sustained demand; an HVLP turbine or airless rig where the finishing job needs one; a dust collector. **access.** Operation is simple: the controls are few. That is not the same as safe for a beginner. Follow *safety first*. Real access barriers are the automatic restart, the stored pressure, noise (the MAC2400 is rated 79 dB per Makita via the retailer, not independently measured here), weight and the maintenance burden. **revival.** Compressors remain useful because they run tools with no battery limit and do jobs battery guns do not (blowgun, inflation, staplers, pinners). Whether one is worth owning depends on the tools you will actually run. Current prices and availability change; none are stored here. Compare total system cost (hose, fittings, filters, dryers, maintenance) on the day. --- ## anatomy - **Pump.** Piston and cylinder doing the compressing. On the MAC2400: oil-lubricated, removable cast-iron "Big Bore" cylinder, 1,730 RPM on a 4-pole motor (Makita MAC2400 product page and retailer listing, per the reviewer's source notes; the Makita page was not opened here). - **Motor.** Electric on portable units. See the settlement notes above on horsepower ratings. - **Receiver tank.** The pressure vessel: pancake, hot dog, twin-stack, wheeled vertical or horizontal. Verify the code marking and rating on the exact nameplate and in the manual. Its life is finite and condition-dependent. - **Pressure switch.** Cycles the motor between cut-in and cut-out pressure. A stuck switch is one reported route to overpressure. - **Safety (pressure-relief) valve.** Last defense against overpressure. Check and replace per the manual for the exact model. - **Check valve.** Holds tank pressure when the pump stops. - **Regulator and gauges.** Tank pressure and regulated outlet pressure are different fields, as are maximum pressure, cut-in, cut-out, accessory maximum and required working pressure. - **Drain valve.** At the tank's lowest point. Condensate collects there. - **Couplers.** Hose interface. - **Roll cage, frame, handle.** Carry and protection. --- ## variations (living) Record these as design and maintenance choices, not rankings. Compare exact models on delivered SCFM at stated pressures, duty cycle, sound test value, weight, serviceability, required oil and manufacturer life or warranty information. | Variant | What differs | Typical use named by the retailer guide | |---|---|---| | **Pancake** | Flat single-drum tank, compact | Trim and finish nailing, small jobs | | **Hot dog** | Single horizontal cylinder tank | Intermittent nailer and stapler work | | **Twin-stack** (e.g. MAC2400, 4.2 gal) | Two stacked cylinder tanks, more reserve in a carryable footprint | Mixed trim and jobsite nailing | | **Wheelbarrow** | Wheeled frame, larger tanks, gas engine available | Crews and unpowered sites; gas units need their own controls | | **Wheeled vertical or horizontal** | Larger tank on wheels | Garage or shop duty beyond hand-carry | | **Oil-free pump** | No oil maintenance | Check the model for noise, duty cycle and rated life | | **Oil-lubricated pump** | Needs oil checks and changes | The MAC2400 is rated 79 dB and runs at a lower RPM per Makita; that supports that model's design only, not a category ranking | | **Battery** | Battery-powered hand-carry | No dated origin found | Source for the format list: "Portable Air Compressor Buyer's Guide," Air Compressors Direct [read in the original pass; retailer guide]. --- ## trades - Trim and finish carpentry, cabinet installation. - Framing and roofing crews (wheelbarrow and gas class, with their own controls). - Furniture and small-shop woodworking: nailing jigs, stapling, finishing under the spray gate, cleaning under the blow-cleaning gate. - Upholstery: Paslode's first pneumatic tool (1959) was an upholstery tacker, per Paslode's own history. - Automotive and mechanical: inflation, blowguns. --- ## lineage **Ancestors** - **The bellows.** It moves air but stores almost none. A receiver gives a compressor stored reserve that a bellows lacks. (Not every compressor differs from a bellows only by having a receiver; this is a simplification.) - **Industrial compressed air.** Compressed-air rock drills were used on the Mont Cenis tunnel (1857 to 1871). Britannica's Ninth Edition, "Tunnelling", is cited by the reviewer as period-adjacent evidence for the dates and the productivity change [not opened by Hewn]. The Paris compressed-air network (from 1881, over 900 km of mains, running until 1994) rests here on a secondary synthesis: Kris De Decker, "History and Future of the Compressed Air Economy," Low-Tech Magazine, May 2018 [read in the original pass]. Technological resemblance is not direct product descent. - **The steam boiler, on the failure axis.** Receiver-tank safety rules are part of a larger pressure-vessel history, see *history*. **Contemporaries** - **The stationary shop compressor** (large vertical, often two-stage, 240V) has higher delivery, a real duty cycle and permanent plumbing. It is a parallel member of the same broad family, not a descendant of the hand-carry format; stationary industrial systems are historically earlier. - **The tankless inflator** (12V, 120V, cordless). A tankless unit usually lacks the delivery, duty cycle, fittings and reserve for shop pneumatic tools. "Tankless" alone does not prove zero useful capability. - **The dust collector** is the other shop-infrastructure air mover, and its opposite: large volume at almost no pressure versus small volume at high pressure. **Descendants and rivals** - **Battery compressors.** No dated first-to-market source was found, so no origin claim is made. - **Cordless fuel-cell nailers.** Paslode's own history dates its first cordless fuel-cell nailer to January 1986 (manufacturer self-history, interested source). --- ## history **The code behind the tank, as context.** ASME's published history of the Boiler and Pressure Vessel Code records thousands of 19th century boiler explosions and names the Grover Shoe Factory explosion in Brockton, Massachusetts, March 10, 1905 (58 deaths, 117 injuries) as a catalyst. The code was conceived in 1911; the 1914 Edition was published in 1915; and 49 US states and all Canadian provinces have adopted various sections by law [ASME, Domeric Canonico, "The History of ASME's Boiler and Pressure Vessel Code," Dec. 1, 2010; read in the original pass]. **Limit of that evidence:** it does not show that every portable compressor tank in every jurisdiction is ASME-stamped or that every valve is ASME-rated. Stamping, exemptions, inspection and retirement depend on the product and the jurisdiction. Check the nameplate and manual for the exact receiver. **The portable receiver-mounted unit, early patent.** US1756806A, "Portable air-compressing unit," Howard W. Beach, Caldwell, New Jersey, filed October 28, 1927, issued April 29, 1930, individual assignee [read directly on Google Patents by Hewn, 2026-10-03]. It describes a self-contained portable compressor on a truck frame, motor and compressor above the frame and two pressure tanks below it, intended for pneumatic tools, paint spraying and sandblasting, electrically powered. That is a truck-mounted unit, not a hand-carry pancake, so it shows early portable self-contained units, not the origin of the modern format. The review notes an earlier Ingersoll-Rand "Portable compressor unit," US1415047A (filed March 31, 1921, issued May 9, 1922) in Beach's citations [per the reviewer; not opened here]. The earlier record US1802175A named in the first draft does not resolve to the claimed patent and has been removed. **No source located names who introduced the pancake or hand-carry format, or when.** That is a named gap. **Pneumatic nailers and the compressor market.** Paslode's company history dates its first pneumatic tool (an upholstery tacker) to 1959 and the GN-212 to 1962, and calls the GN-212 the world's first pneumatic nailer. That is an interested source. US2729198A, "Pneumatic nailer," filed November 27, 1951 and issued January 3, 1956, describes a portable hose-fed magazine nailer [per the review; the page could not be opened, so not verified here]. It does not prove a commercial launch, but it undercuts an unqualified "first in 1962" claim. The growth of portable compressors alongside construction nailers is a plausible, important market link. It is not a proven single cause: inflation, spraying, service work and other pneumatic uses also existed, and no market data was found for the claim. **The horsepower settlement, stated carefully.** Around 2004, a settlement covered compressors from Campbell Hausfeld, DeVilbiss Air Power, Ingersoll-Rand and Coleman Powermate purchased August 1, 1996 to January 31, 2004, with a claim deadline of October 21, 2004 and credits or products up to $50. The source is a woodworking-forum relay of the settlement notice (Sawmill Creek, "Compressor Settlement โ€” Reminder"), not a complaint, settlement agreement or order. It supports that the named defendants settled allegations that motor horsepower was misrepresented, and per the reviewer's reading, without an admission of liability. It does not establish that each label was false or why. Court documents were not located. **Sanity check on units:** a nominal 120 V, 15 A circuit can supply at most about 1,800 W of electrical input (120 x 15), about 2.4 HP before any losses. Input power, motor output, peak, developed and continuous ratings are different things, so a label figure cannot be compared to this bound without knowing which one it states. --- ## human side **Brockton, 1905.** The boiler at the R.B. Grover shoe factory failed and leveled the building with the workforce inside: 58 dead, 117 injured. The safety codes for pressure vessels grew out of events like this one. **The Garage Journal autopsy.** A Garage Journal thread (thread 492545, "Catastrophic air compressor explosion warning") shows named practitioners reading a burst horizontal tank on an approximately 20-year-old Campbell Hausfeld unit [read in the original pass; forum testimony, not engineering analysis]. American Locomotive: the tank "told them many years ago... they welded the holes shut and kept it operating." WordMan: it "failed at the seam, not at the repair." Steve_P describes a "ribbon" of water on the bottom of horizontal tanks that forms "a line of corrosion and reduced metal thickness; this can cause them to unzip." Packard V8 raises overpressure from a failed shutoff or relief valve as the other path. u2slow: "test your pressure relief valves โ€” at least annually," and the original poster, wazzabie, drains after each use and leaves the drain open in storage. These are practitioner opinions on one video, not verified causes. The most human detail is a tank already welded once being kept in service. **The car wash, 2005.** OSHA IMIS Accident 201146958: on July 23, 2005, an 80-gallon vertical receiver (rated 200 psi, manufactured 1982) exploded in the equipment room of an automated car wash; an employee in the next room died of blood loss from abdominal and pelvic injuries [read in the original pass; osha.gov could not be reopened by Hewn]. Investigators found the relief valves functioning and no corrosion in a visual inspection, and the root cause was not definitively established. **This entry uses the case only for two things: stored-energy severity, and the fact that a visual inspection after a failure did not reveal a cause.** It does not show that draining, visual inspection, valve testing or a retirement age would have prevented that failure, and it is not offered as evidence for any of them. Each preventive control in this entry is sourced independently. The tank was industrial scale, not hand-carry. **The claim-form woodworkers.** When the settlement was announced, Sawmill Creek members checked their own machines against the class list. Ron Schweitzer joined to file on his Craftsman; moderator Chris Padilla found his qualified. --- ## proof of existence Access status is stated for each. "Read in original pass" means the 2026-07-10 pass fetched it; Hewn could not reopen it. - **CPSC Recall 02-108 (2002-02-26).** Read in original pass; characterized also in the reviewer's notes. HIGH. - **OSHA IMIS Accident 201146958 (2005-07-23).** Read in original pass; not reopened. HIGH for the event facts, nothing about cause. - **ASME BPVC history.** Read in original pass. HIGH for Grover and adoption; not for any specific compressor tank. - **US1756806A (Beach, 1927/1930).** Read directly this pass (Google Patents). HIGH for the bibliographic data. - **US1415047A, US2729198A.** Per the reviewer only; Hewn could not verify (not opened). Not verified here. - **Paslode company history.** Read in original pass; interested source. MEDIUM. - **OSHA 1910.242(b), STD 01-13-001, 1994 interpretation.** Directive wording by search summary only; rule text by original pass quote; interpretation per the reviewer only. Not opened here. - **Makita MAC2400 manual and product page.** Per the reviewer's notes and search summary only; not opened here (blocked). - **Sawmill Creek settlement thread.** Read in original pass; secondary relay. MEDIUM. - **US1802175A.** Removed, does not resolve. - **Museum or archival holding.** Not searched. --- ## references Access status key: **OPENED** (Hewn, this pass); **SEARCH SUMMARY** (title and summary seen in search results, page blocked); **ORIGINAL PASS** (fetched 2026-07-10, not reopened here); **PER THE REVIEWER** (taken from the review, not verified by Hewn). - [A1] U.S. CPSC, Recall 02-108, Feb. 26, 2002, "CPSC, Ingersoll-Rand Co. Announce Recall of Portable Air Compressors Sold Between 1983 and 1991" (cpsc.gov/Recalls/2002/cpsc-ingersoll-rand-co-announce-recall-of-portable-air-compressors-sold-between-1983). ORIGINAL PASS and PER THE REVIEWER. - [A2] OSHA IMIS Accident 201146958 (osha.gov/ords/imis/accidentsearch.accident_detail?id=201146958). ORIGINAL PASS and PER THE REVIEWER. - [A3] "Catastrophic air compressor explosion warning," The Garage Journal, thread 492545. ORIGINAL PASS. Forum testimony. - [A4] Domeric Canonico, "The History of ASME's Boiler and Pressure Vessel Code," ASME, Dec. 1, 2010. ORIGINAL PASS and PER THE REVIEWER. - [A5] Campbell Hausfeld Cast Iron Series Air Compressor operating manual, doc. 254702. ORIGINAL PASS. A different model, used only as a labelled example of manual wording. Not the Makita manual. - [A6] "40 Years of Innovation: The History of Paslode," Paslode UK & Ireland. ORIGINAL PASS. Manufacturer self-history. - [A7] OSHA 29 CFR 1910.242(b). ORIGINAL PASS (verbatim quote) and SEARCH SUMMARY. - [A8] "Compressor Settlement โ€” Reminder," Sawmill Creek Woodworking Community (2004). ORIGINAL PASS. Forum relay of a settlement notice. - [A9] Kris De Decker, "History and Future of the Compressed Air Economy," Low-Tech Magazine, May 2018. ORIGINAL PASS. Secondary synthesis. - [A10] "Portable Air Compressor Buyer's Guide," Air Compressors Direct. ORIGINAL PASS. Retailer guide. - [A11] Makita MAC2400 product page (makitatools.com/products/details/MAC2400) and Makita MAC2400 instruction manual (cdn.makitatools.com/apps/cms/doc/prod/MAC/507b8b6f-ef3e-4886-8b22-324f829c1990_MAC2400_IM.pdf; also listed at makita.ca owner's-manual PDF for MAC700, MAC2400, MAC5200). PER THE REVIEWER, with a SEARCH SUMMARY of the 20 ft spray separation and no-flammable-vapor warnings. Not opened by Hewn (network blocked). The first pass's Acme Tools listing is a retailer secondary source ORIGINAL PASS. - [A12] U.S. CPSC, "Air Compressors Recalled by MAT Industries" (2014). ORIGINAL PASS. A non-tank recall (pressure-switch shock hazard); named so the tank-rupture record is not inflated. - [A13] OSHA directive STD 01-13-001, "Reduction of Air Pressure below 30 psi for Cleaning Purposes" (osha.gov/enforcement/directives/std-01-13-001; also at labor.nc.gov). SEARCH SUMMARY only. - [A14] OSHA standard interpretation, 1994-01-14, on cleaning people and clothing with compressed air (osha.gov/laws-regs/standardinterpretations/1994-01-14). PER THE REVIEWER only. - [A15] OSHA 29 CFR 1926.302 (rated pressure for hoses and fittings; construction pneumatic tools). PER THE REVIEWER only. - [A16] US Patent 1,756,806 A, "Portable air-compressing unit," Howard W. Beach (patents.google.com/patent/US1756806A/en). OPENED. - [A17] US Patent 2,729,198 A, "Pneumatic nailer" (patents.google.com/patent/US2729198A/en). PER THE REVIEWER; the page could not be opened. - [A18] US Patent 1,415,047 A, "Portable compressor unit," Ingersoll-Rand. PER THE REVIEWER only. - [A19] Encyclopaedia Britannica, Ninth Edition, "Tunnelling" (Wikisource). PER THE REVIEWER only. - [B1] Lowe's and McCoy's MAC2400 listings (4.2-gallon tank; 130 PSI max; 4.8 CFM at 40 PSI). Search-index tier, not opened. Superseded by [A11] per the reviewer. - [B5] Spray-gun and continuous-tool air-demand figures. Never fetched. No figures asserted. --- ## safety first (read before anything else) The manual for your exact model is the rule source. When this entry and the manual differ, the manual wins. Do not carry one model's intervals, parts or procedures to another. **What the compressor can do to you.** Per the reviewer's source note on the Makita MAC2400 instruction manual (the manual was not opened by Hewn), the manual identifies: electric shock, fire or explosion, unsafe pressure, breathing exposure, propelled debris, automatic cycling and moving parts, hot surfaces, tank rupture and accessory bursting. **Access statement (the reviewer's recommended wording, kept close to it).** The controls are straightforward, but the machine stores high-pressure air and can restart automatically while switched on. Before use: - Read the exact model manual and the manual of every attached tool. - Inspect the tank, cord and plug, hose, couplers and fittings, guards, drain and safety valve. Stop on leaks, corrosion, dents, damaged wiring, abnormal noise or vibration. - Use a grounded, correct-voltage circuit and the manual's extension-cord guidance. Keep the unit dry. - Keep it ventilated, stable, and clear of flammable vapor. - Set the regulator within the rating of every connected part (hose, coupler, regulator, tool, spray gun, tire, accessory). - Control the hose and coupler when connecting and disconnecting. Keep hoses off trip paths and away from hot or sharp surfaces. - Wear eye protection around compressed air and when draining. Control the drain outlet and follow local condensate-disposal rules. - Keep clear of the hot head and discharge tube and of all moving parts and guards. **Isolation before service or attachment changes.** Switch off, unplug, and bleed the stored pressure before maintenance, repair or changing attachments. (Search summary of the MAC2400 manual: "always unplug the compressor and release air pressure"; exact context and wording not verified here.) A pressure switch and a safety-relief valve cover different failure paths. Neither replaces shutting the machine down by hand when it runs abnormally. **The compressor does not make the tool safe.** A nailer, sprayer, blowgun or inflator brings its own hazards and manual. Keep attached-tool safety separate. ---