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What Goes Into a Drone Soft Wash Van Build

Tim Cray 6 min read

Key takeaways

  • The soft-release unloader is the drone-specific part. A trapped-pressure unloader kicks the aircraft when the operator triggers, while a block-mounted soft-release unloader dumps pressure for a smooth start and takes stress off the pump.
  • Two spray systems, not one. An AR45 handles the high-volume, low-pressure work most drone cleaning is, with an 8 GPM, 3,500 PSI Honda GX690 pressure washer alongside it.
  • Pure water needs its own path. High-flow sediment and carbon pre-filters feed two DI tanks in series, and the mixer's fourth valve sends chemical-free water up for glass and panel work.
  • Hose weight matters. Smooth-jacket Fierce Jet pressure hose and 3/8 inch AR45 line are lighter to lift to altitude, and every hose end is crimped with no clamps anywhere.
  • Most companies do not need this build. A drone rig pays off on high-rise glass and large facades; otherwise a conventional skid or trailer serves far better for the money.
In this guide
What Goes Into a Drone Soft Wash Van Build - Expert Power Wash

Cleaning drones get the attention. The van parked at the curb is what decides whether the drone actually works.

A drone operator is asking a ground rig to send water and chemical several stories up a hose, hold a steady mix while doing it, switch between pure water and bleach without landing, and do all of it without jolting an aircraft that is hovering next to somebody's glass. That is a different set of requirements than a normal wash rig, and most of the choices in this build come straight out of them.

Here is a 2023 Ford Transit high roof we built for a drone cleaning operation, and why it is put together the way it is.

The unloader is the drone-specific part

If you take one thing from this build, take this one.

The pressure washer is a custom Honda GX690 at 8 GPM and 3,500 PSI. What makes it suitable for drone work is a block-mounted soft-release unloader.

A trapped-pressure unloader holds pressure in the hose when you come off the trigger. On the ground that is a non-issue. Hanging off a drone, that stored pressure releases as a jolt the moment the operator triggers, and the aircraft feels it. A soft-release unloader dumps pressure instead of trapping it, so the drone gets a smooth start rather than a kick.

Block mounting it does something else worth knowing about even if you never fly anything. Pulling the unloader off the pump and mounting it to the frame, plumbed with half inch hose, takes the mechanical stress off the back of the pump. Pumps last longer.

A few other details on the machine: a genuine Honda exhaust rather than an aftermarket one, an upgraded charging system, and the exhaust tapped down through the van floor so it vents underneath. The machine pulls fuel from the van's own tank, plumbed so it can only draw down to about half a tank — you cannot strand yourself on a job.

Two spray systems, not one

The pressure washer is not what feeds the drone most of the time. An AR45 system does.

The AR45 handles high-volume, low-pressure work, which is what most drone cleaning actually is — sending a house wash or roof mix up ten stories at volume rather than blasting at pressure. It can pull from either the buffer tank or the pure water tank, so the same machine does dirty work and rinse work.

You can run a larger pressure washer to a drone instead, and this van can do that too. Having both means the operator picks per job rather than per rig.

Three tanks and a mixing block

Water, bleach and soap each have a tank, and the mixer meters all three into the line with individual valves and numbered indicators.

Roughly how it gets used:

  • House wash: water on, soap bumped low, bleach dialed in — usually somewhere around the 1 mark as a starting point
  • Roof or heavy moss: water wide open, bleach wide open, which lands near a 50/50 mix
  • Pure water only: water, soap and bleach all off, and the fourth valve opened to the pure water tank

That last one matters for drone work specifically. A lot of what drones get hired for is glass and panel work where you want no chemical at all and no spotting on the dry-down.

The same mixing logic applies to any soft wash rig — we cover it in detail in How a Soft Wash Mixing System Actually Works, and the mixers themselves are in the soft wash mixers collection.

Three ways to get pure water out

The purification side is a high-flow window cleaning system: high-flow sediment and carbon pre-filters, then two DI tanks in series. High flow matters because a system sized for a single window cleaner will choke a drone operation.

Water comes in through a 3/4 inch garden hose — bigger hose, faster fills — hits a selector valve, and goes either to the buffer tank or through purification to the pure water tank.

From there it can leave three ways: through the pressure washer, through the AR45, or through the water-fed pole system, which runs off its own remote-controlled pump so the operator can vary flow from the pole rather than walking back to the van.

Reels and hose

All 12 inch Titan electric reels with heavy-duty guides, carrying:

  • 100 ft of garden hose
  • 200 ft of Fierce Jet smooth-jacket pressure hose — lighter than standard jacket, 4,250 PSI working with a 10,625 burst rating, and rated to 310°F
  • 3/8 inch hose for the AR45, rated 800 PSI

Weight is the reason for both hose choices. Every pound of hose is weight the drone has to lift and drag. The smooth jacket is lighter than a standard braided jacket at a higher rating, and the smaller AR45 line is easier to get up to altitude than a fatter one would be.

There is also a ball valve on the pressure side so the operator can switch between the drone line and a ground gun or surface cleaner without repluming anything.

The parts nobody photographs

The whole build is 316 stainless. Brackets, mounts, hardware. The reel rack is quarter inch aluminum, fabricated in our shop. The tanks are strapped through part of the van frame rather than just to the floor, so nothing shifts on the road.

Every hose end is crimped. No hose clamps anywhere on the build. Clamps are a field failure waiting to happen, and a failure on a drone job is not a puddle — it is an aircraft in the air with no water.

The water-fed pole reel is a Tucker system on a quick connect, so it pulls out of the van entirely and can be used as a standalone window cleaning cart.

Is this the right build for you?

Honestly, for most exterior cleaning companies, no. A drone rig makes sense when you are consistently getting work on buildings you cannot safely or economically reach from the ground — high-rise glass, large commercial facades, structures where scaffolding or lifts eat the margin.

If that is not your work yet, a conventional skid or trailer will serve you far better for the money. We would rather tell you that than sell you a van.

If it is your work, or you are moving toward it, the closest thing we keep listed is the Aqua Flow Pressure Washing Soft Wash Pure Water Drone Skid. Everything we build is custom, so the real starting point is a conversation about the buildings you are cleaning and the drone you are flying.

Further reading

We build skids, trailers, vans and truck mounts in Oregon City, Oregon, and ship nationwide. Book a discovery call to talk through a build, or reach the shop at 503-403-6185 (landline, no texts), Monday through Thursday, 8am to 4pm.

Frequently asked questions

What kind of unloader do you need for a drone pressure washing rig?
A block-mounted soft-release unloader. A trapped-pressure unloader holds pressure in the hose when you come off the trigger, and hanging off a drone that stored pressure releases as a jolt the aircraft feels. A soft-release unloader dumps pressure instead, so the drone gets a smooth start. Block mounting it on the frame with half inch hose also takes mechanical stress off the back of the pump.
What pressure washer do you use for drone cleaning?
This van runs a custom Honda GX690 at 8 GPM and 3,500 PSI with a genuine Honda exhaust, an upgraded charging system and the exhaust tapped through the van floor. It pulls fuel from the van's own tank, plumbed so it can only draw down to about half a tank. Most of the time, though, an AR45 high-volume, low-pressure system is what actually feeds the drone.
How does a drone soft wash van switch between bleach and pure water?
Water, bleach and soap each have a tank, and a mixing block meters all three with individual valves and numbered indicators. For house wash, water is on, soap is bumped low and bleach is dialed in around the 1 mark as a starting point. For roof or heavy moss, water and bleach are wide open, near a 50/50 mix. For pure water, all three are shut off and a fourth valve opens to the pure water tank.
How is pure water made on a drone cleaning van?
Water comes in through a 3/4 inch garden hose, hits a selector valve and goes either to the buffer tank or through purification to the pure water tank. The purification side is a high-flow window cleaning system: high-flow sediment and carbon pre-filters, then two DI tanks in series. High flow matters because a system sized for a single window cleaner will choke a drone operation.
What hose should I run to a cleaning drone?
Weight drives the choice, since every pound of hose is weight the drone has to lift and drag. This build carries 200 ft of Fierce Jet smooth-jacket pressure hose, lighter than standard jacket at 4,250 PSI working, 10,625 burst and rated to 310°F, plus 3/8 inch hose rated 800 PSI for the AR45. Everything is on 12 inch Titan electric reels with heavy-duty guides.
Is a drone pressure washing van worth it for my business?
For most exterior cleaning companies, honestly no. A drone rig makes sense when you are consistently getting work on buildings you cannot safely or economically reach from the ground, like high-rise glass, large commercial facades, or structures where scaffolding or lifts eat the margin. If that is not your work yet, a conventional skid or trailer will serve you far better for the money.
Written by

Tim Cray

Owner, Expert Power Wash

Tim and Kristina ran their own pressure washing company for more than ten years on trailers, box trucks, flatbeds, vans and skids before Expert Power Wash started building equipment for other contractors. Today EPW has 300-plus builds working in the field and services pressure washing rigs in the Oregon City shop every day.

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