Qwik Spray vs High Pressure Spray for Hard Coat: Which to Use?

The two most common spray methods VFI hard coat products utilize are Qwik Spray and high pressure spray. Spraying, in general, provides applicators with several advantages – speed, uniformity, and reduced labor costs – compared to roller and brush applications.

Those new to spraying can benefit by starting with a cartridge-based applicator. However, it can also be hard to know if it is the best application method for you. There may come a time when your production line could benefit from upgrading to a high-pressure spray rig. Maybe you started making small displays and signs for retail stores but have recently been contracted for bigger work by theme park and attraction companies. VFI has excellent technical and customer service support to guide you when making this important decision.

Note: Always wear proper protective equipment (PPE), including an approved respirator, regardless of what equipment you’re using. Also, utilize a well-ventilated spray booth where necessary.

Qwik Spray Gun Requirements

VFI-6171 70 D Qwik Spray Hard Coat is the cartridge-based polyurethane formula VFI recommends for protecting smaller EPS theming elements. To use the material, you will need a VFI-7500 Qwik Spray Gun capable of holding 750 mL dual cartridges, an air compressor that supplies clean, dry air at a minimum of 100 psi and 10 cfm of constant pressure, and GS-15 Static Mix Tips.

VFI-6171 is stored in cartridges with two separate chambers for the A (Iso) and B side (Poly) materials. The design of the cartridges ensures a precise 1:1 mix ratio by volume that achieves a quality protective finish. Once the trigger is pulled, the components are pushed into and mixed through the static mix tip, which initiates a chemical reaction that cures the material after it exits the tip. The GS-15s have an 11-inch mix tip with a 3/8-inch inner diameter, which creates a fine texture on surfaces.

High Pressure Spray Rig Requirements

VFI-6170 70 D Spray Hard Coat is the high pressure polyurethane formula VFI recommends for protecting larger EPS theming elements. To use this material, you will need a two-component air, electric, or hydraulic sprayer that runs at a minimum of 150-155°F and 2,500 psi of constant pressure, with heated lines. Some spray rigs that accommodate these requirements are:

• Graco A-XP1 air sprayer
• Graco Reactor 2 E-XP2 electric sprayer
• Graco Reactor 2 H-XP2 hydraulic sprayer
• Graco Reactor 2 H-XP3 hydraulic sprayer
• PMC PHX-2 hydraulic sprayer
• PMC PHX-25 hydraulic sprayer

Advantages of Using the Qwik Spray Gun

1. Portability

A big reason the Qwik Spray System is so desirable to many users is because all you need is the lightweight applicator and enough cartridges to cover your piece at the desired thickness. Since this method is typically recommended for smaller projects (under 90 square feet), you’ll probably only need a kit of material, which is just 6 cartridges. With improved portability of the material and equipment, you can go from job to job much easier and aren’t held down to a single location for spraying. Note: This will also be dependent on the size of your air compressor.

2. Cost-effective for Small Projects

If you’re spraying small sculptures, custom signs, scenery, or props for a museum, retail store, theater production, etc., the VFI-6171 formula is preferable. Small projects typically include pieces 4 feet x 6 feet and under. Anything over this size will generate a large amount of overspray. Other small jobs this material can help with are if you need to repair an existing hard coat that has become damaged or adhere large EPS pieces together for a larger project.

The Qwik Spray Gun is more affordable, and while the material might cost more, you’ll save a lot on equipment if you’re not hard-coating massive theming projects. If you want a quality spray rig, they can cost upwards of $20,000-$80,000 or more. The higher end would be for mobile rigs with compressors and generators, so your spray equipment is easier to transport.

3. Better for Minimal Spraying

Many applicators can’t justify the price that comes with high pressure machinery if they are not spraying frequently. The Qwik Spray System is a great alternative if your production only calls for spraying a couple of times per month. However, there are situations where applicators have justified upgrading even if they only spray once a month.

Someone might eventually switch to high pressure if their spray load increases substantially, as they would save upwards of 60% in material costs if they switched from Qwik Spray. Two cartridges are just under a gallon of material and are significantly more expensive than purchasing in gallons or drums.

4. Limited Training Necessary

Another reason users desire the cartridge-based applicator is due to ease of use. Because the machinery is less advanced, applicators don’t need as much training to use it. If you’re new to the Qwik Spray System, check out our how-to-use guide with pictures for easy assembly and tips on spraying.

VFI recommends this spray applicator to get users started when they don’t have any previous experience. It allows applicators who are used to applying coatings with brushes or rollers to experience a low pressure version of spraying. Note: If you’ve never sprayed before, it will take some practice to achieve a consistent, desirable finish.

5. Low Maintenance

A big perk about cartridge-based spray application is that there are no spray lines to clean after spraying. Empty cartridges and static mix tips can be thrown away after use, so there’s limited mess and maintenance. The cartridge-based applicator does not require frequent use to keep it in working condition.

On the other hand, high pressure spray equipment requires a lot of maintenance to prevent downtime from chemical buildup, corrosion, and other factors. You have to clean spray nozzles, pumps, lines, etc. frequently. VFI offers VFI-8005 Pump Flush for cleaning spray lines to prevent material from clogging the equipment. It also has more parts that can wear over time, so it’s important to inspect and replace them to ensure your equipment is in working order.

Advantages of Using a High-Pressure Spray Rig

1. Better for Increased Project Volume

If you’re suddenly spraying almost every day vs a couple of times per month, it may be time to upgrade to a high pressure spray rig. As mentioned, the material costs for a cartridge-based system are more substantial. When you start to notice that you’re buying cases upon cases of cartridges, switching over to drums or totes can make a huge difference.

Note: High pressure spray rigs must be used often to keep them in working condition. If you do not have plans to use the spray rig, you should flush the spray lines so that coating residue is not left to solidify or crystallize.

2. Better for Versatile Spraying

When you have a high pressure spray rig, there’s no limit to the types of jobs you can work on. Whether your carved EPS structure is small, medium, or large, the spray rig will accommodate it.

Another thing that makes high pressure rigs so versatile is that they can be used with different materials. Polyurethane and some hybrids are typically the only material that can be used with cartridge-based equipment. If you’re looking for a material that’s a bit softer than a polyurethane or hybrid coating for your theming project, high pressure polyureas have been used in their place.

3. Better for Fixed Location Spraying

While the portability of the Qwik Spray Gun is desirable, if you’re not going on-site to spray a hard coat, that portability doesn’t always matter. Many theming designers have workshops where they do it all: carve shapes and forms, spray hard coats, and paint over them. These shops typically also have a designated spray booth to contain overspray and protect their work environment and workers from harmful spray fumes.

4. More Control While Spraying

A negative part of the application process when using a Qwik Spray Gun is once you start spraying, you’re not supposed to stop. Continuous spraying is necessary because if the flow is stopped, the coating will clog up in the static mix tip. You need to plan your spray route ahead of time for a consistent, uniform finish. If you want to stop, you’ll have to switch applicator tips before you start again.

With a high pressure spray rig, you can start and stop when you need to. Having control also reduces the amount of material used, so there’s less waste.

5. Improved Cured Surface

Something that tends to be insignificant to some applicators but can save on time and labor costs is how the coatings cure. The high pressure hard coat formula comes out smooth, seamless, and free of blemishes due to the pressure and speed at which the coating exits the applicator. It has less time to interact with the environment, which could cause potential issues.

The Qwik Spray formula, on the other hand, is slower and doesn’t come out of the applicator with as much force. This gives it more time to interact with the environment, which creates a foaming effect from moisture in the air. While the surface irregularities aren’t that noticeable, it will be more textured. This might create more post-work, such as sanding before the application of a top coat can occur.

Contact VFI if you’re still trying to determine whether the Qwik Spray or high pressure hard coat is better for your unique project.