Preventative maintenance is critical to the effectiveness of any equipment, no matter its quality. Effective preventative maintenance, however, requires sticking to a schedule. Without a plan in place that's designed to identify equipment problems before they can happen, you risk putting yourself in a situation that could impact your business and the performance of your equipment, which will more than likely impact your bottom line.

Spray professionals are always on the lookout for equipment that optimizes mixing performance to produce the smoothest surface for foam and coatings. In many cases, mechanical purge spray guns are the go-to to meet these requirements. Thanks to multiple impingement fluid ports, both components are mixed thoroughly to ensure spray quality is top-notch. Material that's atomized through a round or flat tip delivers a smoother finish than that of an air purge gun. Mechanical purge guns also require less air than air purge varieties. On the other hand, drawbacks of mechanical purge systems include added gun adjustments. Round tips are also more susceptible to being plugged quick than an air purge round mix chamber.

We've discussed before the benefits of an effective preventative maintenance schedule and why the success of your spraying activities depend on it. But now it's time to get more specific and look at particular pieces of equipment that can, from time to time, malfunction. It's up to you to have a plan in place that mitigates the impact of these issues before they become more significant and more costly issues.

Impingement spray guns are versatile pieces of equipment that can heat chemical components to produce both polyurea and polyurethane before mixing. This heating process reduces the viscosity of your spray material to improve mix, flow, and leveling, which boosts the performance of your spray gun to produce a gorgeous final product. These sprayers offer up to 95% efficacy and are most effective in many applications, including roof coatings, pipe and tank coatings, truck bed liners, waterproofing and roof and wall insulation.

Common Impingement Spray Gun Issues (and how to Solve Them) 

Due to high pressure and temperature envelopes, impingement spray guns are known to suffer more frequent malfunctions than other types of spray guns. Fortunately, many of the issues with impingement spray guns are predictable and easy to diagnose. The majority of the issues with these spray guns are found in the valves, nozzles, as well as the mixing chamber. Some of the issues with impingement spray guns include:

• The gun doesn't fully actuate after the trigger is squeezed. This malfunction can result from three primary issues. First, the safety lock may be engaged, which can be solved by disengaging it. Secondly, the muffler may be plugged by solidified residue. You can solve this by cleaning the muffler with a compatible solvent. Lastly, a lack of full actuation may be caused by damaged air valve o-rings, which will require replacement.
• Lack of fluid flow after full actuation. In some cases, even after full actuation, the foam may not discharge correctly. A closed fluid valve may be causing the problem, which is solved by opening the affected valves and clearing them of any residual materials. This issue is also caused by plugged impingement ports or check valves, which in both cases can be solved quickly by cleaning the ports and valves with a compatible solvent.
• Slow or abrupt gun actuation. If your spray gun is taking a long time to actuate, you may have an issues with a blocked muffler, which will require cleaning. The malfunction can also be caused by damaged pistons or o-rings. These components will need to be replaced if it's determined that they're causing the issue. In some cases, actuation may occur but can stop abruptly, which is caused by either residual material that's cured around side seals from a past job or a retaining ring that hasn't bottomed out completely.
• Loss of spraying pattern (circle or flat). An Impingement Spray Gun is designed to spray foam in patterns. This helps in leveling the sprayed surface to achieve a more consistent finish. In some cases, however, the pattern is disrupted by what could be a range of issues, such as a dirty mix chamber nozzle, a clogged spray tip, or a worn tip. This can be solved by cleaning the chamber nozzle or blocked spray tip with a solvent. On the other hand, in case the tip is worn, it can be replaced.
• A leaking mix chamber or flat tip. Due to high-pressure, impingement spray guns are known to suffer from leakage in both the mixing chamber and the spray tip. In this case, the flat tip may be loose and need to be reassembled. Alternatively, the o-rings may be damaged or missing completely, and require replacement.
• Pressure imbalance. The high-pressure envelopes may cause an imbalance that can affect spray outcome. This malfunction is often caused by plugged impingement or check valves.

A Preventative Maintenance Schedule That Works

(NOTE: Compatible solvents include N Methyl Pyrrolidone (NMP), Dynasolve CU-6, Dzolv, or equivalent to soften the cured material. ) 

Daily maintenance

1. Because impingement spray guns operate with high-pressure envelopes, pressure relief procedures can help to identify any potential malfunctions. 
2. Greasing an impingement spray gun on a daily basis helps to avoid component curing during mixing while keeping fluid passages clean
3. Clean outside of gun with a compatible solvent.
4. 4. Clean mixing chambers daily to eliminate any clogged materials that may affect performance.
5. Clean the air cap using a solvent and an appropriate drill to minimize actuation issues. 
6. 6. A clean fluid manifold improves mix and flow efficiency to boost performance and finish quality. Clean the manifold using a solvent with a stiff brush. Make sure to clean both fluid ports on the top mating surface without damaging the flat sealing surfaces. Greasing the fluid manifold when left exposed seals out moisture.
7. Clean passages and impingement ports to reduce clogging and actuation issues.

Weekly to Monthly Maintenance

1. Clean the mixing chamber and side seal cartridges meticulously at the end of every working week. Major repairs may be done at the end of the month.

2. Every seven days, disassemble and clean check valves to eliminate any potential clogging issues.

Never Underestimate the Value of Preventative Maintenance

By having a plan in place that keeps your mechanical purge spray gun operating at peak efficiency produces an automatic competitive advantage compared to those who don't take the process of establishing a maintenance schedule seriously.

If you're unsure where to start, or need help in selecting a mechanical purge spray gun that can help you perform spray jobs more efficiently while producing the highest-quality finishes, Bolair has the expertise you need to make the right choice.

For over 35 years, Bolair has leaned on its expert fluid handling knowledge to help the industry's best contractors and manufacturers grow their businesses.

Don't hesitate to reach out today to see how we can help.