Pros: Excellent performance for price ratio
Outperforms most gas station air pumps
Cons: Not well suited to small volume applications
Inaccurate air pressure gauge
The Master Flow MF-1050 Tsunami High Volume Portable Air Compressor is a 12-volt portable high-volume air compressor designed for heavy-duty applications such as the rapid inflation of multiple truck and large SUV tires. As such, it’s a perfect choice to be carried aboard a vehicle for off-road travel and/or camping trips, where it can provide air on demand from the vehicle’s 12-volt battery or any 12v source.
In addition to filling flat or underinflated tires, the price and compact size of the MF-1050 solves the problem of what to do after purposefully deflating, or ‘airing down’ for a comfortable, tire-preserving ride when traveling off-pavement. The MF-1050 can also be used to fill air tanks to power air tools, as well as to inflate air ride or airbag type suspension systems used on some RVs and fifth wheels.
Design and Features
The official name for the listed compressor is the Master Flow MF-1050 Tsunami Air Compressor, sold in the United States by Q Industries. It carries a three year limited warranty.
The MF-1050 is a 12-volt, single cylinder/piston (oil-less) compressor, using a 1/3 HP motor to provide a maximum of 150 psi air pressure (though frequently listed in various advertisements as a dual cylinder compressor, it is actually a single-cylinder design.) The complete kit includes the compressor itself, a built-in air pressure gauge, alligator-clip power cord with a fusible link for direct attachment to the vehicle battery, a coiled 16-ft hose with air line quick disconnects, a screw-on brass inflation nozzle, a detachable, serviceable air filter, instruction booklet, and a neat storage bag to carry it all. The MF-1050 has a maximum operating voltage limit of 13.8v, with a maximum amperage draw of 30 amps.
Unlike the typical high-pressure compressors sold for emergency automobile use or to inflate bicycle tires, the MF-1050 is all about high-volume, being designed to fill big empty things like vehicle tires or air tanks. In the case of this particular compressor, the output volume is 2.54 cubic feet per min (72 liters per minute) from the cylinder head, and about 1.8 cubic feet per minute (50 liters per minute) measured at the hose end. This means that the MF-1050 will inflate the average car or truck tire about three times faster than the average emergency 12v compressor (or for that matter, most coin-operated gas station air pumps), and do so without overheating in the process.
As is common with high-volume portable 12v compressors, the MF-1050 connects using alligator clips that are coupled directly to the vehicle battery. The hood is left open and the host vehicle’s engine is left idling during compressor operation. Providing high volumes of air takes a lot of power (amperage), and with a typical draw of at least 22-30 amps when in use, the MF-1050 would fry most vehicle cigarette lighter or power port circuits. Some owners with a bit of electrical wiring ability remove the alligator clips and hardwire the power cord into the vehicle electrical system, then bolt the compressor into place for a more permanent mounting (remember that the compressor must always be located where it can obtain adequate cooling).
With such a large power draw, the vehicle must be running at idle when the compressor is in use to keep an adequate charge on the battery. Operating the MF-1050 is relatively simple. First screw the provided air filter into the cylinder head, while placing the compressor flat on the ground. All small compressors tend to move a bit in operation due to piston vibration, so don't leave the MF-1050 on a fender or bumper, where it could vibrate off and fall onto the ground. Next, attach the air hose to the compressor, then screw the inflator nozzle onto the tire valve. Attach the alligator clips to the battery as directed: red (positive) clip to positive battery post, then black clip (negative) to ground. Finally, turn the power switch to 'on' to commence pumping. A fusible link installed in-line with the power cord provides a safety measure in the event the unit malfunctions, overheats or otherwise begins to draw an excessive amperage from the battery. The manufacturer recommends against powering the compressor 'on' unless the air line has already been attached to the tire valve. When used with an air tank, a backflow prevention device (blowoff valve) must be installed to prevent damage to the cylinder head air valve.
In testing, I found that the MF-1050 would inflate a 31x 10.50R Jeep tire from 10 psi to 35 psi in about 2.5 to 3 minutes per tire. A 285/75R16 truck tire took 3.25 minutes to inflate from 10 psi to 35 psi. Four tires inflated from 10-30psi took about 13 minutes, not counting time in switching and attaching the air line. A 7-gallon air tank can be filled from 0 to 100 psi in about 2.5 minutes.
Of course, there is an outside limit to the running time of almost any portable compressor, and the MF-1050 is rated for a maximum continuous operating time of 40 minutes (a maximum of 30 minutes is recommended) before it must be disconnected to allow it to cool for twenty minutes before restarting. This limit should always be observed, but especially so in hot weather (over 100 degrees F). Given the unit’s large output and the amount of draw it places on the vehicle battery, this limit seems quite reasonable.
The MF-1050 is fitted with an automatic thermal protection switch. In the event the compressor reaches an unsafe operating temperature, a circuit breaker will cut power to prevent damage. In the event this circuit breaker trips, disconnect the compressor from the battery and allow it to cool for at least fifteen minutes before attempting a restart. The protection circuit will automatically reset when the unit is cool enough to resume pumping air.
Advantages and Disadvantages
The primary advantage to the MF-1050 is price to performance ratio. This little compressor will air up the average car tire from flat to maximum pressure in two minutes or less, and a large 35-inch truck tire in about 6.5 - 8 minutes. There are few if any portable compressors in its price range that can provide anywhere near the same performance, and many are much more expensive.
The MF-1050 seems reliable enough after two years of use, no complaints so far. My current offroad vehicle is a 4WD truck with a diesel engine and two batteries. This got me to thinking – two compressors for two batteries, with half the inflation time. So for $59 I bought a second unit to speed the airing-up process and to have a backup.
The screw-on inflation nozzle has a useful 'deflator' feature that comes in handy when airing down tires for an off-road excurson. Partially screwing in the nozzle allows air to escape the tire valve, while unscrewing the nozzle all the way closes the tire valve at the air pressure desired.
Disadvantages include the the air line hose fitting at the cylinder head, which instead of being a normal NPT thread is a hard-to-find 10mm metric size. As such it will not accommodate common ¼” NPT air fittings. If your hose should crack or split later on, you’ll have to buy a replacement from the manufacturer. Some owners have cured this by removing, tapping and rethreading the cylinder head for an NPT replacement (this of course voids the warranty). If you do this, remember that the MF-1050 uses an air line with straight-through type quick-disconnect couplings. If you afterwards install a standard NPT hose with cutoff-type quick-disconnect fittings and happen to disconnect the air hose from the tire while the compressor is still operating, pressure will rapidly build in the closed-off air line that could easily damage the cylinder air valve.
While the screw-on air hose nozzle works well for the most part, it does result in a small air loss when being unscrewed from the valve stem, so one must slightly overfill to compensate. The air gauge does not give accurate readings while the compressor is operating – one must power off the compressor to get a reading. Even then, the gauge reads the air pressure at the cylinder head instead of at the tire, which will normally be about 5-10 psi higher than the pressure in the tire itself. You'll want to carry an accurate digital tire pressure gauge for final checks on tire pressures.
While the MF-1050 is great for airing up truck, car, and even motorcycle tires, it’s not well suited to small volume applications. It will inflate a standard 26-inch mountain bike tire in about two-and-a-half seconds – not much room for error there. Don’t even think about using it to inflate basketballs or other toys.
Price Paid: $59