Can the Graco GX 21 pump also be used to spray varnish? What accessories do I need? Since this topic comes up regularly by email, we have answered all questions about it in detail in this blog post.
Here is the customer’s request:
Hello, I have purchased the Graco GX 21 pump. I also want to spray varnishes and lacquers (water-based) with this device. What do you advise me to do, what accessories do I need for this? Sincerely, XXX
Is the Graco GX 21 pump suitable for spraying varnish?
The Graco GX 21 is a small entry-level sprayer for interior wall painting. The equipment is therefore designed for this type of application. The suction hose sucks the paint directly from the paint bucket.
The hose between the spraying device and the gun has a length of 15 m and a diameter of 6 mm. This offers the advantage that the Graco GX 21 can be positioned in the hallway and, with 15 m of hose, you can reach every room in the apartment without having to move the sprayer.
The choice of nozzles supplied with the pump (Graco LP517 for wall paint, Graco FFLP310 for varnish) is also focused on wall paint with the LP517. The same goes for the #60 mesh gun filters that come with the unit.
Lacquers and varnishes are generally used in smaller quantities than wall paint. If you want to paint doors, windows, radiators or a wooden ceiling, small quantities of paint of a few liters are usually sufficient.
If you want to paint the walls of an apartment or a single-family house, you will need several 15-liter buckets of paint. The equipment configuration of the Graco GX 21 therefore has advantages for the application of wall paint and disadvantages for the application of varnish.
What are the disadvantages of painting with the Graco GX 21?
The disadvantages are especially noticeable when applying small amounts of material, for example when painting a single garage door. Before starting work, the GX 21 must be filled with paint. The suction hose and the 15 m paint hose are designed for wall painting and therefore have a larger capacity. If a very small amount of paint is to be used, the disadvantage is that the suction and paint hose must first be filled with paint. This means that more paint is used than is necessary and a little material is “wasted”.
Be careful if solvent-based paints are to be used. Wall paint is water soluble, but if solvent-based paints are to be used as well, there is another problem. Glycerophthalic paints dissolve water-soluble paint residues in the airless and the hose or react even if the cleaning is not very thorough. This can lead to regular clogging of the filter and the nozzle, which is very disruptive to the work.
What can you do if you also want to use solvent-based paints with the GX 21?
A. Clean airless and hose thoroughly before changing products.
B. Use an extra hose for solvent-based materials to prevent water-soluble paint residue from coming off in the hose.
C. When working with solvent-based paints on a regular basis, it is recommended to use a second unit such as the Graco GX FF. Thus, one airless can be used for water-based materials and the second for solvent-based paints.
The best alternative, the Graco GX FF pump
For this reason, Graco has also developed a varnish version of the GX 21 pump to overcome the above-mentioned disadvantages when applying paint. The Graco GX FF pump has a suction hopper with a capacity of 5.7 liters.
This shortens the product path compared to the Graco GX 21 and reduces the amount of paint needed to fill the sprayer. The paint hose also requires less paint volume, as it is only 7.5 m long and has a smaller diameter.
What accessories are needed to apply varnish with the Graco GX 21?
If one accepts the disadvantage of over-consumption and changing accessories between applications (from wall paint to lacquer and vice versa), it is also possible to spray lacquer with the Graco GX 21.
However, this requires suitable paint nozzles and filters (gun filters for lacquer here). Graco FF LP nozzles are suitable, the choice of the right nozzle size depends on the material to be applied and the surface.
In the following video, we explain in detail how to choose the right nozzle for each project.
In addition, it is recommended to use a shorter and thinner paint hose of 7.5 m length for regular application of small amounts of paint.
Is there a hopper for the Graco GX 21?
There is no official conversion kit with a funnel for the Graco GX 21 from the manufacturer Graco. There are a few pictures of conversions circulating on the internet as some DIYers have used a funnel adapted to other Graco models.
Unfortunately, this funnel cannot be easily mounted on the Graco GX 21, you have to build a bracket yourself. One wonders if this is worth the time spent, the cost of the funnel and the additional cost of a paint hose, filters and nozzles compared to the purchase price of the Graco GX FF.
People who regularly use lacquers should consider whether it’s worth buying the Graco GX FF as an add-on unit rather than converting the Graco GX 21.
In addition, it saves the expense of changing the product between lacquer and wall paint, because with the Graco GX 21 you have to change the hose, gun filter and nozzle each time. In practice, this is often forgotten and you end up on the job site with the wrong equipment, which can cause delays in the work.
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