How to Set Up and Use a Raincovo Foam Cannon

The short answer

A Raincovo foam cannon clicks onto the 1/4-inch quick connect on your pressure washer's gun or wand, the same socket the coloured nozzle tips go in. You fill the bottle with water and car-wash soap, set the knob on top for how thick you want the foam, turn the nozzle for a wide fan or a narrow jet, and spray. 5 of Raincovo's 7 cannons also come with an extra 1.1 mm orifice for washers that make less than 1,500 psi, and that one swap is the difference between thick foam and thin soapy water on a small electric machine.

Two of the range work differently. Pure Pro Foam Cannon and Dual Pure Pro Foam Cannon take concentrated soap poured straight into a small bottle with no mixing at all. Everything else wants a pre-mixed solution.

Before you start: which cannon, which connection

Everything below is read off the listings. “Not stated” means the listing does not say, not that the feature is missing.

Step by step

1. Check the connection. Look at the end of your pressure washer's gun or wand. If the nozzle tips push in and lock with a sliding collar, that is a 1/4-inch quick connect, and every Raincovo cannon in the table with that entry clicks straight on. If the gun ends in a screw thread, it is usually M22; the Snow Clear lists 14 mm M22 compatibility directly, and for the others an M22-to-1/4-inch adapter sits in between.
2. Fill the bottle. For the bottle cannons, put water in first and soap second so it does not foam up in the bottle. Use the ratio printed on your soap. The Snow Pro's bottle is graduated, per its listing, so you can measure rather than guess. For the Pure Pro the listing says to pour about 100 mL of concentrate straight in — no water.
3. Close it without forcing it. The Snow Pro listing warns against over-tightening the lid. Snug is enough; the seal does the work.
4. Set the thickness. The knob on top controls how much soap is drawn into the water stream. Start in the middle and turn towards more soap until the foam clings. On the R 2.0 the knob is damped with clicks, which the listing says is to stop it being knocked off your setting.
5. Set the pattern. Turning the nozzle moves the spray from a narrow jet to a wide fan. A wide horizontal fan covers a car fastest.
6. Spray and wait. Work from the bottom of the car up, so the foam on the lower panels, which are the dirtiest, stays on longest. Let it dwell for a few minutes without drying, then rinse from the top down.

The orifice: the one part worth understanding

A foam cannon makes foam by forcing water through a small hole (the orifice) that creates suction, which draws soap up from the bottle. How thick the foam comes out depends on how much pressure and flow the washer supplies. A smaller orifice keeps that suction up on a weaker machine. That is why 5 of the listings include an extra 1.1 mm orifice, and why Snow Clear Foam Cannon, Snow Pro Foam Cannon, Foam Cannon Kit with Short…, Snow Clear Foam Cannon… say plainly that it produces more foam below 1,500 psi.

The listings do not state the size of the orifice fitted at the factory, and none sells a set of alternative sizes. What you have is the one in the cannon and the 1.1 mm spare.

Changing it: on Snow Pro Foam Cannon, Pure Pro Foam Cannon, Foam Cannon R 2.0 the front nozzle unscrews by hand, which the listings describe as tool-free access to the foam maker. Unscrew the nozzle, lift out the old orifice, drop in the 1.1 mm one, and screw the nozzle back. Do it with the bottle off and the cannon rinsed, so soap residue does not glue the parts together.

Common problems, and what the listings say about them

• Thin, runny foam. Almost always not enough pressure for the orifice fitted. Fit the 1.1 mm orifice if your washer is under 1,500 psi, turn the top knob towards more soap, and use a soap made for foam cannons.
• Leaking at the lid. Over-tightening distorts the seal, per the Snow Pro's own care tip. The R 2.0's cap adds a check valve and a half-turn lock, which its listing describes as a fix for exactly this.
• Pure Pro dripping after filling. Its listing says to turn it upside down straight after filling. The bottle mounts on top and feeds by gravity.
• Nothing comes out on a garden hose. Expected. Foam Cannon Kit with Short…, Foam Cannon R 2.0 state that they are for pressure washers only. A foam cannon needs the washer's pressure to work.

Looking after it

Every care note in the listings says the same two things. Rinse the cannon with clean water after each use: run plain water through it for a few seconds so soap does not dry inside the orifice and the filter. And store it indoors, out of direct sunlight, which is what degrades a clear plastic bottle over time. If a bottle or cap does fail, Raincovo sells a few spares, and they are listed in Raincovo Foam Cannon Parts, Bottles and Orifices.

Questions

Written from Raincovo's own Amazon listings. Availability last checked 2026-09-11; figures are rebuilt from the listings rather than typed in.