When it comes to achieving professional paint finishes, gravity spray guns are the go-to choice for painters across the UK and Ireland. Whether you're working on refinishing, furniture restoration, or precision coating applications, understanding how gravity feed spray guns work can transform your painting results from good to exceptional.
At Ultrimax, we've been helping professionals achieve outstanding finishes for over 50 years. This comprehensive guide covers everything you need to know about gravity spray guns, from how they work to which models deliver the best results for your specific applications.
How Do Gravity Spray Guns Work?
Gravity spray guns operate on a simple yet effective principle that delivers superior performance compared to traditional suction systems. The paint is stored in a cup mounted on top of the gun, allowing gravity to naturally feed the paint directly into the spray pattern without requiring suction pressure.
Here's the process when you pull the trigger:
- Compressed air enters through separate passages in the gun body
- Air meets paint at the precisely engineered nozzle
- High-velocity air instantly atomises paint into fine droplets
- Creates a uniform fan pattern with precision control
- Needle valve regulates paint flow while air cap determines pattern quality
This gravity-fed design eliminates the vacuum effect needed in suction guns, meaning your compressor doesn't work as hard and you achieve better atomisation at lower air pressures. Most gravity guns operate effectively between 8-20 PSI, compared to 25-35 PSI for suction systems.
Why Choose Gravity Over Suction Spray Guns?
The question of gravity versus suction spray guns comes up frequently, and for good reason. The performance differences are significant enough to impact both your results and your bottom line.
Gravity spray guns deliver superior performance in several key areas:
- Paint transfer efficiency: 90-95% compared to just 60-70% for suction guns
- Lower operating pressure: 8-20 PSI versus 25-35 PSI for suction systems
- Better atomisation: Produces finer, more uniform droplets for smoother finishes
- Reduced overspray: Less waste means lower material costs and cleaner work environment
- Easier clean-up: Paint flows completely out, leaving minimal residue
Suction guns still have their place in certain applications, particularly when you're working with large volumes or heavy-bodied materials that benefit from continuous feed systems. However, for precision work where finish quality matters most, gravity systems are the clear winner.
The choice often comes down to your specific application. For furniture work, and detailed coating projects, gravity systems offer the control and quality you need. For large-scale industrial painting or production work where speed exceeds fine finish quality, suction guns may be more practical.
How to Use a Gravity Spray Gun
Getting consistently professional results from your gravity spray gun starts with proper setup and technique. Many painters struggle with inconsistent finishes simply because they haven't mastered these fundamentals.
Preparation is absolutely crucial
Start by thoroughly cleaning your gun and checking that all seals, gaskets, and components are in good condition. Your paint preparation matters just as much - always strain your paint through a fine mesh filter to remove any contamination that could affect the spray pattern or clog the nozzle.
Paint viscosity requires careful attention. For water-based materials, aim for 18-20 seconds in a flow cup, while solvent-based paints typically work best thinned to 16-18 seconds.
Correct spraying technique makes all the difference:
- Maintain 6-8 inches distance from the surface
- Keep the gun perpendicular to your work
- Move in smooth, parallel passes with 50% overlap
- Start spraying off the edge and release the trigger before reversing direction
- Begin with minimal paint flow and gradually increase until you achieve the desired coverage
Start with test panels to understand how your specific gun responds to different settings, then apply those learnings to your actual work.
Understanding Optimal Pressure Settings for Gravity Spray Guns
One of the most common questions we hear is "what's the best pressure for my gravity spray gun?" The answer depends on your application, but understanding the general principles will help you dial in perfect settings every time.
Base coats and primers: Typically work best at 12-18 PSI. This range provides good coverage while minimising texture and overspray. You want enough pressure to achieve proper atomisation without creating excessive bounce-back that wastes material and creates contamination issues.
Colour coats: Perform optimally at 10-15 PSI for most applications. This pressure range delivers the fine atomisation needed for smooth, even coverage while avoiding the orange peel texture that can ruin an otherwise perfect paint job. The key is finding the sweet spot where you get complete atomisation without excessive pressure that creates overspray.
Clear coats: Require the lowest pressures at 8-12 PSI to achieve that glass-like finish quality. Ultra-fine atomisation prevents texture while ensuring maximum gloss development. Many painters make the mistake of using too much pressure for clear coats, which creates texture and reduces the final gloss level.
Environmental conditions affect your settings too. Higher temperatures typically require reducing pressure by 2-3 PSI to prevent flash-off issues, while high humidity may need a slight increase to maintain proper atomisation.
What are the Disadvantages of Gravity Spray Guns?
While gravity spray guns offer exceptional performance, they do have limitations that you should understand before making your purchase decision.
Limited paint capacity: is the most obvious limitation. With cups typically holding 150-600ml, you'll need frequent refills on large projects. This interrupts workflow and makes gravity systems less suitable for high-volume production work where continuous spraying is essential.
Angle limitations: present challenges in certain situations. You cannot spray effectively upside down or at extreme angles because gravity won't feed the paint properly. This restricts access to some areas and orientations during application, potentially requiring different gun positions or additional equipment.
Top-heavy design: can cause operator fatigue during extended use. As the cup empties, the balance point shifts, which some painters find tiring over long spray sessions.
Paint compatibility: issues can arise with certain materials. Extremely thick coatings, heavy primers, or textured finishes may not flow properly through gravity feed systems.
Gravity Spray Guns at Ultrimax
Our carefully curated selection of gravity spray guns represents the best in professional spray equipment. We stock proven performers from industry-leading manufacturers, each chosen for reliability, performance, and long-term value.
- Iwata W400 Bellaria Gravity Spray Gun - delivers exceptional performance for professional applications. This gun combines Iwata's renowned precision engineering with modern materials and design for consistent, high-quality results across a wide range of applications.
- Iwata LPH80 Mini Gravity Spray Gun excels at touch-up work, graphics, and small component finishing. Its compact design and precise control make it ideal for intricate work where larger guns would be difficult to operate.
- Iwata W300 WB Gravity Spray Gun, specifically engineered for optimal performance with water-based materials. As environmental regulations push more painters toward water-based systems, this gun delivers the performance needed for professional results.
- The Satajet 1000 B RP Gravity Spray Gun brings German engineering excellence to your workshop. SATA's reputation for precision and durability makes this gun a favourite among professionals who demand the best.
Essential Accessories and Support Equipment
Professional spray gun operation requires more than just the gun itself. At Ultrimax, we stock everything you need to maximise your equipment performance and maintain professional standards.
The Ultrimax Magnetic Spray Gun Holder systems keeps your workspace organised and your guns secure. Available in both 1-gun and 2-gun configurations, these holders prevent damage and contamination while keeping your equipment easily accessible.
Ultrimax Gravity Feed Strainers (275-micron) are essential for maintaining paint quality and preventing contamination that could ruin a perfect finish. Professional painters know that clean material is just as important as proper technique.
Replacement cups, lids, and accessories ensure your equipment stays operational. We stock genuine replacement parts to maintain your gun's performance and extend its working life. Proper maintenance prevents costly downtime and ensures consistent results.
Maintenance Tips for Long-Term Performance
Your gravity spray gun represents a significant investment that deserves proper care. Following a structured maintenance routine prevents problems and ensures consistent performance over years of use.
Understanding spray equipment goes beyond just gravity guns. Our comprehensive guides cover related topics that can improve your overall painting performance:
- Which Paint Sprayer Should You Buy? - Compare different spray systems for your applications
- Maximising the Benefits of Lacquer Paint - Get the most from your finishing materials
Get Expert Advice from Ultrimax
Choosing the right gravity spray gun can seem overwhelming with so many options available. That's where our experience makes the difference. With over 50 years in the industry, we understand the pressures that come with professional painting and stock.
Our Total Paint Shop Support Team provides technical expertise to help you select the right equipment for your specific applications. Whether you're upgrading from suction guns, expanding your capability, or starting fresh, we can guide you to the optimal solution.
Ready to upgrade your spray equipment? Browse our complete range of Gravity Spray Guns or contact our team for personalised recommendations.