Gear Box Spray Paint Booth &
Gearbox Painting – Autocoat Engineering
Autocoat Engineering has more than 53 years of long experience and expertise in supplying paint shops for gear box painting. One of the leading manufacturers of Spray Booths for gear boxes, paint booths for gear boxes and painting of geared motors. Based in Thane, Maharashtra since 1985.
About Gear Boxes & Gear Box Painting
The purpose of a gearbox is to increase or reduce speed. As a result, torque output will be the inverse of the speed function. If the enclosed drive is a speed reducer (speed output is less than speed input), the torque output will increase; if the drive increases speed, the torque output will decrease. A gearbox is a mechanical component used to change the speed (RPM) and increase the motor’s torque. The shaft of the motor is associated with the gearbox via gears.
Autocoat Engineering has a long experience of more than 53 years and expertise in supplying paint shops for gear box painting. Autocoat is one of the leading manufacturers in the field of manufacturing Spray Booths for gear boxes, paint booths for gear boxes and painting of geared motors. For any painting line, choice of process development is very important — due to Autocoat’s vast experience, customers are guided in the most effective way.
All paints used in gear box painting have excellent resistance to various atmospheric conditions and give better aesthetics. Surface preparation is a must before any paint film is applied on the gear box body. Gear boxes have multiple components — cast iron, EN8, shafts, stainless steel, mild steel etc. Each part needs to be treated separately due to its metallurgical properties. Components like shafts are to be kept unpainted so that they do not lose their mechanical properties.
Surfaces That Do Not Require Coating
The following gear box surfaces will not require protective coating:
Gear Box Painting Process – 4 Stages
Autocoat’s complete gear box painting process covers four distinct stages — from initial pretreatment through to final finish colour coating:
Pre-Treatment of Gear Box Casting
Pre-treatment and cleaning of gear box casting surfaces is the most important stage. As soon as the housings are checked and passed for further process, the pre-treatment activity begins.
This process can be achieved by a minimum of a 7-tank process up to a 12-tank process. It is always recommended to have a zinc phosphating stage in the pretreatment process (hot bath). The phosphate coat creates a thin whitish surface on the casting body, making it advantageous for good paint adhesion. This pretreatment process can also be carried out by the Shot Blasting Method. Once pretreatment is completed, the casting is transferred to the gear box paint booth.
Gear Box Painting — Primer Coat on Jigs
Smaller gear box castings are placed over a jig so that multiple castings can be painted with grey primer or red oxide in the gear box paint booth. The dry film of the primer is normally 20–30 microns by one coat of primer painting.
Larger and heavier gear box castings are painted one at a time — electric hoist material handling is preferred in this case. With the selection of the right paint booth, undesired overspray is removed from the painting area, creating a smooth primer finish over the casting.
Mid Primer Coat & Surface Cleaning After Assembly
At assembly and testing stages, gear box primer surfaces often tend to have grease and oil marks. At the testing stage there is also a chance of abrasion or scratches on the primer-painted surface. These marks need to be polished with polish papers.
A mid primer coat is then applied in the Gear Box Spray Booth. Autocoat also recommends maintaining a clean environment near the painting area at this stage to ensure the mid primer coat achieves a defect-free surface ready for the final finish coat.
Final Finish Colour Coat
After the above stages, the assembled gear boxes are finally painted using two methods depending on size and weight — or directly by wet-on-wet process:
Conveyorised Gear Box Painting Method — for smaller gear boxes. Autocoat has designed, developed and manufactured Slat Conveyors for heavy assembled geared motor painting. Conveyorised geared motor painting booths are faster and economical, running almost on a 3-shift basis trouble free.
Paint Booth for Gear Box with Monorail / EOT Handling — for large frame or heavy gear boxes. Industrial Spray Booths for geared motors with monorail handling equipment and heavy duty slat conveyor for transit enhance the painter’s capability to lift, lower and rotate the geared motors for all-around coverage.
Training sessions are conducted to educate painters and subordinates for maximum productivity and effective maintenance of gear box spray booths. Every booth is manufactured, assembled, numbered, tested and live trials are given to the customer for complete satisfaction before dispatch. Detailed instruction manuals, SOP laminations and TPM activity guidance are included with every unit.
Two Methods for Final Gear Box Painting
The final finish colour is applied by two different methods depending on the size and weight of the gear box:
Conveyorised — Small Gear Boxes
Slat conveyor — fast & economicalAutocoat has designed, developed and manufactured Slat Conveyor systems for heavy assembled geared motor painting — running almost on a 3-shift basis, trouble free.
- Slat conveyor for continuous flow
- Fast, economical — 3-shift operation
- Consistent film thickness on all units
- Suitable for small to medium gear boxes
- Reduces manpower and cycle time
Monorail / EOT — Heavy Gear Boxes
Lift, lower & rotate — full coverageIndustrial spray booths for geared motors with monorail handling equipment and heavy duty slat conveyor for transit — enabling the painter to lift, lower and rotate heavy gear boxes for all-around painting.
- Monorail & EOT arrangement
- Lift, lower & rotate heavy gear boxes
- Full 360° coverage on complex shapes
- Reduces operator fatigue significantly
- Efficient & matches pollution board norms
Gear Box Paint Booth – Installation Photos
Actual photos of Gear Box Spray Paint Booths and geared motor painting lines supplied by Autocoat Engineering:
Gear Box Spray Booth – Key Features
7 to 12 Tank Pretreatment
Comprehensive pretreatment from 7-tank up to 12-tank process — with recommended zinc phosphating (hot bath) for maximum paint adhesion. Shot blasting also available.
Jig-Based Primer Painting
Small gear box castings placed on jigs for multi-piece primer painting in the booth. Dry film of 20–30 microns achieved by one coat of primer — with right paint booth ensuring smooth finish.
Monorail & EOT for Heavy Gear Boxes
Industrial spray booths with monorail handling and heavy duty slat conveyor — allowing the painter to lift, lower and rotate heavy geared motors for complete all-around coverage.
Slat Conveyor for High Volume
Autocoat has designed, developed and manufactured Slat Conveyor systems for heavy assembled geared motor painting — running on a 3-shift basis trouble free for maximum productivity.
Pollution Board Norm Compliance
Autocoat gear box spray booths are very efficient and match pollution board norms — ensuring complete capture of overspray and maintaining a clean, compliant working environment.
Painter Training Sessions
Training sessions are conducted to educate painters and subordinates for maximum productivity and effective maintenance of gear box spray booths throughout their working life.
Conveyorised vs Monorail / EOT – Comparison
| Feature | Conveyorised (Slat Conveyor) | Monorail / EOT Handling |
|---|---|---|
| Best For | Small to medium gear boxes | Large, heavy gear boxes |
| Throughput | High — 3-shift continuous | Flexible batch |
| Material Handling | Slat conveyor — automated transit | Monorail / EOT hoist |
| Component Rotation | Fixed jig position | Yes — lift, lower & rotate |
| All-Round Coverage | Conveyor jigs | Full 360° with EOT |
| Operator Effort | Low — slat conveyor transit | Assisted by hoist |
| Production Speed | Fast & economical | Flexible per component |
| Pollution Compliance | Yes | Yes |
Gear Box Paint Booth Applications
Autocoat Gear Box Spray Paint Booths and geared motor painting lines serve the following applications: