Today we are looking at the commissioning of the Graco GX 21 sprayer. The Graco GX 21 is an entry-level device, which means that many users have their first contact with airless spraying with this spraying device, which naturally leads to many questions and sometimes problems as well.

That’s why today we’re going to take a closer look at getting started with the Graco GX 21 pump. We hope that this article will help you avoid these problems and get started right away in a professional manner.

Mise en route de la pompe Graco GX 21 – Trucs Airless #66

The Graco GX 21 sprayer

Before starting the commissioning, a few words about this pump, so that you know which buttons and functions are available on the device and thus use it optimally. The paint is sucked into the device through the suction hose, the pump pressurizes it.

The paint is then transported through the blue hose to the gun. Here the material is sprayed. On the side of the machine is an on/off switch. Further on, a pressure regulator allows the pressure to be continuously adjusted from zero to maximum.

Starting up the Graco GX 21 pump - Pressure gauge

Starting up the Graco GX 21 pump – Pressure gauge

Important: On the side is the discharge valve. It is used to control the flow of product. On the one hand, it is used upstream of the gun and, on the other hand, to pump the product back to the paint bucket via the small return hose.

Starting up the Graco GX 21 pump

To start up the Graco GX 21, you need to pump out the preservative still in the unit or even the water from the last project, and replace it with paint.

The same goes for the hose, so that the paint is present throughout the system and you are ready to work and then spray a wall or something.

Graco GX 21 Pump Start-Up - Preservative Pumping

Graco GX 21 Pump Start-Up – Preservative Pumping

Step 1

First, you need to separate the suction hose and the return hose. There are clips for this purpose, so that it is easy to disassemble and reassemble the whole. The return hose is hung in the empty bucket and the suction hose in the paint bucket. The paint is of course already mixed.

Mise en route de la pompe Graco GX 21 - Débrancher le tuyau de retour

Starting up the Graco GX 21 pump – Disconnect the return hose

Step 2

The next step is to open the discharge valve. This is necessary so that the preservative or water can be pumped from the unit into the empty bucket.

First, the sprayer must be turned on and the pressure increased slightly. It is necessary to continue this until paint comes out of the return hose. This indicates that the device is completely filled with paint.

Mise en route de la pompe Graco GX 21 - Ouvrir la soupape de décharge

Starting up the Graco GX 21 pump – Open the relief valve

Step 3

The next step is to connect the return pipe to the main pipe. To do this, simply use the clamps and press them against the main hose. Then, simply close the discharge valve so that the paint flows into the hose before the gun.

Graco GX 21 Pump Start-Up - Suction & Return Hose

Graco GX 21 Pump Start-Up – Suction & Return Hose

Step 4

You take the gun and unscrew the nozzle holder and nozzle. The best way is to take the gun and hold it with the trigger already pressed into the bucket of dirty water and aim the spray against the wall of the paint bucket, so that the paint spray is broken there. Otherwise, and this is real life, you will spray yourself and part of the room with liquid 😉

Next, you’ll need to increase the pressure to get the pump to start working and get the paint flowing through the paint hose and out of the gun.

Starting up the Graco GX 21 pump - Gun in the paint bucket

Starting up the Graco GX 21 pump – Gun in the paint bucket

The Graco GX 21 is now filled with paint, and so is the hose. The preservative and/or water is pumped out of the pump. All that remains is to screw on the nozzle holder and the nozzle, and then to set the pressure optimally on the device.

Setting the optimal pressure on the Graco GX 21 pump

The optimum pressure setting is important, because if you spray with too little pressure, you will get an uneven spray. If you work with too much pressure, you’ll produce a lot of overspray unnecessarily. That’s why we’ve created a separate video in which we show you how to optimally set the pressure of your airless pump.


Finally, you should know that we have written multiple articles about the Graco GX 21 pump on our blog:

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