For large jobs, I run from four to six framing nailers per crew, and I need a compressor that keeps up as those carpenters are nailing like crazy. Whether we're gang?nailing sheathing or sinking nails into LVL, when the compressor tank is drawn down, waiting for a weak compressor to cycle on or having to finish off proud nails with hammers slows us down.
I tested five 15?amp compressors with air?tank capacities ranging from 17 to 25 gallons: the 20?gallon Campbell Hausfeld VT6290, the 25?gallon Craftsman 19541, DeWalt's 17?gallon D55575, Porter?Cable's 20?gallon CPFC2TV3520W, and the 20?gallon Rol?Air 5520HK17.
I ran the machines for more than two months on our jobsites and in the shop, first looking at assembly, gauges, oil change, and pressure output adjustments. Next, I tested each machine's frequency of drain?down and low?pressure performance.
Each unit assembled with no problem. It was a nuisance, though, that additional purchases were required before four of the five units were fully operational. The Campbell Hausfeld, DeWalt, and Rol?Air needed female hose fittings and the Craftsman needed oil. The Porter?Cable was ready to work right out of the box.
Gauges & Housings. The Craftsman, DeWalt, Porter?Cable, and Rol?Air pressure gauges are well placed and easy to read, seem durable, and react quickly to pressure changes. Campbell Hausfeld's are a little smaller, but readable and functional.
The Campbell Hausfeld, Craftsman, and Porter?Cable compressors have plastic housings surrounding their belt drives, which made me wonder what damage a falling 2x4 could do to them.
Air Output & Recovery
I tested each unit to see which ones cycled on and off the most and which ones kept up with constant pressure demands. When the units were drawn down, I checked which ones had enough juice to flush?set nails just before the pump kicked on. Also, you can dial down the output pressure if you end up putting a unit like this on a trim site. The pressure adjustment knobs on all the units worked fine, easily letting me adjust the pressure to the level I wanted.
Air Output. I used each unit on site for six weeks and they kept up with our air demands perfectly. Only the Campbell Hausfeld was a little slow in high?demand applications.
But I also wanted to know if there were differences in pure capacity that might not have shown up out on site or that might be relevant for other uses, like air?hungry pneumatic sanders, grinders, or paint spray guns. I took the compressors into my shop and staged a draw?down test.
I timed how long the compressors took to draw down from full pressure to 90 psi by firing nails from my framing nailer. This test drew more air?faster?from the units than a crew of four gang?nailing subflooring or sidewalls could. It's a pure capacity test designed to show which units keep you nailing or working longest before cycling on.
Full?Pressure Draw?Down. The chart below describes how long it took me to drain each unit from full pressure down to 90 psi driving framing nails into 6?by.
The 25?gallon (the largest tank in the group) Craftsman lasted the longest before its pump kicked on to refill, and the 20?gallon Porter?Cable was close behind. If I was spraying finishes or running pneumatic tools that require huge gulps of air, like an impact wrench, instead of firing framing nails, I'd want the units with the longest draw?down times. I can work in longer bursts before the pump has to refill the tank.
Draw?Down Test Results
Time to 90 PSI
Setting Nails at 90 psi. Most framing nailers require 90 psi to set a nail flush, so I drew the compressors down to 90 psi, then shot nails into 6?inch timbers, checking for "laddered" nails (each successive nail is left higher and higher before the compressor cycles on). The Craftsman and DeWalt compressors drew down to 90 psi and still set nails well. The Rol?Air was impressive, consistently draining to 82 psi and still setting its nails. The Campbell Hausfeld was inconsistent, leaving nail heads standing high at 90 psi.
The Porter?Cable runs at a higher pressure than typical compressors, topping out at 165 psi. It runs down to 100?psi tank pressure before it refills, and it set nails consistently at its low range.