Gravity cup and lid
A sealed cup supplies fluid to the gun. Strain the finish and follow the coating maker's viscosity instructions; do not overfill.
Hand Tools / Spray Finishing Tools / Field guide
HVLP Spray Gun
Follow the path of finish and air through a gravity cup, needle, fluid nozzle and air cap before spraying a test pattern.
Gravity cupFeed
01 / Tool anatomy
See the assembled tool and its components
An original educational poster identifies 10 documented construction features. The numbered descriptions remain readable below the artwork on narrow screens.
- Gravity cup and lid
Hold and feed strained finish into the gun from above.
- Gun body and trigger
Carry fluid and air passages; the trigger opens delivery.
- Front retaining ring
Secures the air-cap assembly to the gun nose.
- Air cap
Shapes atomizing air and the spray fan at the front.
- Fluid nozzle
Defines the fluid opening matched to the needle.
- Fluid needle
Slides to open or close the nozzle as the trigger moves.
- Needle spring and rear knob
Return the needle and limit its rearward travel.
- Fan-pattern control
Adjusts the spray's fan width within the cap set's range.
- Air hose fitting
Connects the gun handle to the matched turbine air supply.
- Cup inlet
Joins the removable cup to the body fluid passage.
Technical references: Fuji Spray T-70/T-75G T-model user manual and parts diagram · Fuji Spray product catalogue. The external T-model fluid and air-path components are separated along their assembly axes. The trigger stays with the body and inaccessible valve internals are not depicted. This is an educational arrangement, not a cleaning or service order. Original educational artwork depicts documented component groups and their relationships; it is not a service sequence or a replacement for the exact model manual.
02 / Understand the tool
What it is and what each part does
An HVLP gun atomizes liquid finish with a high volume of air at comparatively low spray pressure. The Fuji T-75G gravity gun is the documented reference, paired with an appropriate turbine system. Different compressor conversion guns, suction-feed cups and airless pumps require their own instructions; the illustrated gun is not a universal spray-system cutaway.
Liquid descends from the cup toward the fluid nozzle. Pulling the trigger retracts a tapered needle, allowing fluid to pass. Air emerging through the cap breaks it into droplets; the fan control changes pattern shape and the rear fluid knob limits needle travel. Nozzle/needle/air-cap sets must be compatible with the finish and exact gun.
Nozzle and needle
The nozzle meters the fluid opening; the tapered needle closes it when the trigger is released. Treat their sealing surfaces as a matched precision set.
Air cap and retaining ring
The cap shapes atomizing air around the fluid jet; the ring secures its orientation. Its holes must stay clear.
Trigger and adjustments
The trigger admits air and pulls the needle. Fluid and fan controls tune delivery and pattern, but do not replace a correctly sized cap set.
Air inlet
A hose fitting connects the gun to the matched turbine supply. Keep the hose path free of sharp bends and tripping hazards.
01 / Working relationship
How the main groups connect
02 / Fluid and air
Needle, nozzle and cap form the pattern
02 / Working principle
Set, guide and control the action
These decisions make the mechanism useful at the bench.
Prepare the finish
Read the coating technical data sheet and safety data sheet for compatibility, thinning, ignition controls, ventilation and required protection.
Set the pattern
Choose the specified air-cap set, orient the fan, then adjust fluid and fan controls on a test surface with the turbine running.
Control the pass
Hold distance and angle steady, begin motion before triggering, overlap strokes consistently and release after passing the edge.
Furniture and cabinetry
Controlled overlapping passes can build even coats on doors, panels and casework.
Shaped parts
A narrower pattern can reach chair rails, turnings and profiles with less wasted finish.
Sample panels
Test panels reveal atomization, dry spray, runs and compatibility before treating a final piece.
03 / At the bench
Setup, technique and finish quality
Use the steps for a first pass, then inspect the work before changing the setup.
- Read the gun, turbine and coating documents; establish compliant ventilation and personal protection before mixing or spraying.
- Inspect clean cup, nozzle, needle, cap and hose; select a suitable cap set for the coating.
- Strain and prepare finish per its data sheet, then fill and close the cup.
- On a test surface, establish air supply and adjust fan and fluid flow until the pattern is even.
- Spray a moving pass at a consistent angle and distance, overlapping as the coating maker specifies.
- Shut down and clean the gun promptly using the maker's approved solvent and procedure; manage residues safely.
Atomization differs from flow
More fluid is not automatically a better pattern. Tip size, viscosity, air supply and speed interact.
Fan adjustment has limits
Changing fan width does not make an incompatible coating or nozzle set suitable.
Transfer and overspray
HVLP can reduce overspray when configured correctly, but still produces airborne droplets and requires suitable capture and protection.
What changes by model or material
Gravity cups sit above the gun; bottom-feed guns draw fluid from below and use different cup fittings.
Turbine guns need a compatible turbine; compressor conversion guns use regulated clean, dry compressed air.
Sets vary by coating and model. The T-series manual identifies matched replacement parts; do not assume cross-brand interchange.
Choosing the tool
- Match the gun and air source to the coating's technical requirements.
- Compare cup orientation, cap sets, cleaning access and service parts.
- Plan ventilation, filtration, protective equipment and safe storage as part of the system cost.
Useful accessories
- Matching turbine and hose
- Compatible air-cap sets
- Finish strainers
- Spray-test cards and suitable booth filtration
Consumables
- Coating and coating-maker approved reducer
- Appropriate cleaning material
- Replacement seals, needle/nozzle sets and filters
04 / Keep control
Care, troubleshooting and safety
Secure the work, protect sharp edges and release any stored clamping pressure before adjustment or maintenance.
Care checklist
- Relieve supply and empty the cup according to the manual before disassembly.
- Clean nozzle, needle and cap without damaging their precision surfaces.
- Check seals and lid vent; never use a hard wire to enlarge cap holes.
- Keep turbine filters and hose in serviceable condition.
Common mistakes
- Spraying a coating without checking the gun and coating documents.
- Changing fluid flow to compensate for a clogged air cap.
- Pausing with the trigger held over an edge and causing runs.
- Cleaning with an incompatible solvent or leaving finish to cure in the passages.
Safety at the operation
- Provide ventilation designed for spray finishing; keep ignition sources away from combustible vapors and mist.
- Follow the coating SDS and local rules for respirator selection, fit, protective clothing and exhaust.
- Keep electrical equipment and turbine placement within the maker's requirements; never assume a waterborne finish is risk free.
- Handle flammable liquids, oily wastes and cleaning solvents according to their labels and applicable rules.
When the result goes wrong
Stop; inspect cup seal/vent, cap holes, nozzle cleanliness, viscosity and supply air.
Reduce delivery or slow dwell; check pass overlap, distance and coating recommendations.
Check air/fluid balance, distance, room conditions and the coating's allowed thinning.
05 / Sources to keep learning
Manuals and educational resources
Use the exact model documentation for setup, limits and replacement parts. These lessons, documents and model pages teach relevant techniques or help compare real variations.
Manufacturer documentation
Learn and compare
Fuji Spray cleaning video
Maker video and written instructions for cleaning an HVLP gun.
Fuji Spray atomization lesson
Maker explanation of fluid and air balance.
Fuji Spray product catalogue
Official gun and cap-set comparison.
OSHA woodworking finishing hazards
Primary safety guidance on coating hazards and controls.
OSHA finishing PPE
Primary guidance for respiratory and other protection selection.
06 / Manufacturer directory
Manufacturers & Brands
These maker-owned links document relevant tools and tool brands. A product brand may use another company's factory; compare the exact model before choosing parts or accessories.
Fuji Spray turbine HVLP systems and T-model gunsApollo Sprayers turbine HVLP spray systemsEarlex HVLP turbine sprayersWagner HVLP paint and finish sprayersGraco fine-finish spray systemsSATA professional spray gunsAnest Iwata spray guns and finishing equipment
Choose parts for the exact model
Handles, irons, saw plates, clamping pads and other replacements vary by maker and model. Use the maker's documentation before changing a component.
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