Water. Cut-off saws are notorious for their dry-cutting dust clouds. Water attachments reduce the airborne dust to slurry like you would find in a tile saw tub. Eliminating the dust is nice, but don't be misled?you're trading dust clouds for a river of slurry. All the saws come equipped with plastic quick-connect hose couplers. They work, but not for long; we changed them out for tougher brass fittings.
The Right Blade. Don't use composition blades for wet cutting. They're porous and absorb water, which can compromise their structural integrity, causing them to fly apart while in use. Manufacturers suggest not even using composition blades that have been in storage for a year because they may have absorbed humidity. Any diamond blade can be used wet because they're non-absorbent, but diamond blades labeled for wet-cutting perform better wet.
Maintenance & Service
Air Filter. When it's time to clean the air filter I want a dry pre-filter that I can remove without tools, tap clean, and re-install. The careful cleaning is for the shop.
The Multiquip, Partner, and Stihl use oiled pre-filters. The Multiquip uses a thumbscrew to access it while the Partner requires a screwdriver. The Stihl filter access is tool-less and works well. Makita's pre-filter is top-notch. While all the manufacturers recommend cleaning pre-filters with soapy water, Makita's is the only dry pre-filter with tool-less access; a quick tap on a clean surface has me back to the races in nothing flat.
Spark Plugs. You have to change spark plugs less often than pre-filters, but easy access is still good. Makita earns top marks: The same tool-less pre-filter shroud gives you spark plug access. The Stihl spark plug change is tool-free and works nicely. Both the Multiquip and Partner require a screwdriver.
Belt Tension. Improper belt tension can lead to accelerated wear on shafts, bearings, and the belt itself while robbing the tool of power. Stihl's automatic belt adjustment is impossible to screw up: Loosen three nuts and spring tension takes over. The Makita and Partner use an indexed adjusting screw and two bolts, similar to a chain saw, which work fine. The Multiquip uses a wrench-operated cam that also worked well.
Fueling. The Stihl is the only saw you can refuel when it's standing upright. I like this, combined with the large, easy-to-grasp fuel cap. The Makita also has a large, well-designed fuel cap with a tool slot in case the cap gets too tight; it would be better if you could refuel it upright. The Multiquip and Partner fuel caps are similar. They're a little smaller and don't thread as smoothly as the others.
These saws are the big guns of residential construction. The Makita takes high marks for its great power, balance, and controls. It cuts powerfully in and out of position and devours tough materials. The Stihl ranks a close second. It's beautifully balanced with outstanding controls and easy maintenance features. Third comes the Multiquip. Its power, balance, and vibration are satisfactory for most applications. Partner is next with a good guard, power, and fine balance.
David R. Crosby is a custom builder in Santa Fe, N.M., and frequent contributor to Hanley-Wood's TOOLS OF THE TRADE.
Thanks to Hilti for supplying the diamond and abrasive blades for this test.