Popular Mechanics - USA (2022-05 & 2022-06)

12

How to

Use It

RED

0

Highest cutting

action; reserved

for severe jobs

like removing

hardened mud.

YELLOW

15

Powerful cutting

action; use

for removing

paint, stripping

dried dirt.

▼

GREEN

25

Moderate cutting

action; good for

general cleaning

on sidewalks

and siding.

WHITE

40

Mild cleaning

action; suitable

for fabrics,

delicate surfaces,

gentle rinsing.

BLACK

N/A

Reserved

for applying

detergents and

other cleaning

solutions.

SPRAY ANGLE

(DEGREES)

TYPICAL

USES

NOZZLE

→

Pressure washers powered

by a gas engine or an electric

motor are rated in terms of

water pressure in pounds

per square inch (psi) and

f low in gallons per minute

(gpm). Multiply gpm by

psi and you produce a

dimensionless number

called cleaning units (cu),

a rough indicator of the

machine’s cleaning ability.

But psi and gpm each

matter. To strip paint and

blast off mud or barnacles,

you need psi. For general

cleaning power, especially

the ability to rinse the

surface, choose a machine

with greater f low in gpm.

Consider

Cleaning Units,

but PSI and

GPM Are More

Important

PRESSURE WASHING YOUR CAR (DON’T)

There are many great applications
for pressure washers, but using one to
clean your car isn’t among them. The
risk of damaging the finish, blasting
water into head and taillight housings,
or wrecking a wiper blade is just too
great. Yes, a pressure washer is great
for shooting mud or severe grime off

the undercarriage of a pickup truck or

larger vehicle. For general washing,

however, use the time-tested garden

hose and nozzle to produce a low-speed,

high-f low, low-impact stream of water.

Or use a cordless power cleaner, a less

forceful version of a pressure washer

that’s ideal for gentler jobs.

78 May/June 2022