Paint Mixing & Prep Stations

A mixing room is a walk-in enclosure that, as RGI puts it, controls contamination and removes harmful fumes during the paint mixing process. The RGI mix rooms can be connected to paint booths for direct entry.

Six prep stations, four airflow designs

RGI builds these around a common shell, then changes where the air leaves. The four full-size stations and the ECO PREP use 18 gauge zinc galvanized steel panels, companion flanged and pre-punched at 6 in. on center for assembly with 1/4 in. nuts and bolts, in a single-wall gabled roof design. The Mobile Prep-Station sheet lists 18 gauge galvanized single-wall panels punched at 6 in. on center in a self-supporting airtight construction.

• RGI DELTA PREP 250 travels air from the top filter plenum down into a side wall centered exhaust plenum. Widest shell at 16 ft. 4 in. outside, giving a full 14 ft. wide by 24 ft. long by 9 ft. high work area on the 24 ft. model. Also in 27 ft. and 30 ft. lengths.
• RGI VECTOR PREP exhausts through a back wall centered plenum, dropping the outside width to 14 ft. 4 in. for the same 14 ft. work width. It fits a tighter bay, but the rear plenum takes length: 22 ft. 6 in. inside on the 24 ft. model. Listed in the 24 ft. size only; the 27 ft. and 30 ft. sizes on the RGI sheet are not configurable online.
• RGI VECTOR T PREP is a semi-downdraft corner tower exhaust unit, same 14 ft. 4 in. outside width and 22 ft. 6 in. inside length as the VECTOR. Pick it to put the stack in a corner.
• RGI STEALTH PREP is the true downdraft: clean air from the upper fully filtered ceiling, exhaust through the fully filtered floor plenum. Only unit here with a 34 in. fan, and it keeps the full 24 ft. inside length because nothing steals space for a rear plenum. Outside shell is 14 ft. 6 in. wide by 24 ft. 6 in. long on the 24 ft. model; RGI notes the exhaust vent location makes this prep wider than the VECTOR.
• RGI ECO PREP is a plenum box only, not a complete enclosure: 3 ft. long, 4 ft. 6 in. high, in 8 ft. 4 in., 10 ft. 4 in. and 12 ft. 4 in. outside widths, with a 30 in. fan, a 2 hp three-phase motor on the spec list and 16 exhaust filters. You supply the surrounding space or add the optional curtain wall system.
• RGI Mobile Prep-Station is the only prep unit here with a published airflow figure: a 30 in. tube-axial fan at 12,900 CFM on a 2 HP three-phase 240V motor, with five exhaust filters. This model is not configured for online purchase; the product page asks you to call for pricing and availability.

The four full-size stations share a drivetrain: a 30 in. or 34 in. tube-axial fan with aluminum spark-proof blades on a belt drive, a 3 hp three-phase belt-drive motor at 208-230/460V 60 Hz, 4 ft. four-tube LED T8 fixtures on 120V, a Mark Dwyer manometer kit, and 37 in. x 117 in. x 2 in. intake filter pads. Filter counts differ both ways: intake pads are 4 on the DELTA and STEALTH and 2 on the VECTOR and VECTOR T; exhaust filters are 16 on the VECTOR, 14 on the VECTOR T, 12 filters with 14 grids on the DELTA, and 2 on the STEALTH, whose floor plenum uses optional extra filter rolls. All four include a 9 ft. high auto bay curtain with tracking.

Four mixing rooms, sized by footprint

The three RGI families are sized by width, each in three lengths, all at 8 ft. 6 in. outside height. Panels are 18 gauge galvanized or pre-coated white sheet steel, pre-punched and companion flanged for nut-and-bolt assembly. Each includes a 3 ft. by 7 ft. side access man door with observation windows, 4 ft. four-tube LED T8 fixtures on 120V, an 8 in. exhaust blower, a 1/4 hp motor on 120V, two 20 in. x 20 in. x 2 in. intake filter pads, and a 4 in. integrated spill containment that RGI states eliminates the need for a curb.

• RGI MRL-7128: 7 ft. 4 in. outside width, in 12 ft. 6 in., 15 ft. 6 in. and 18 ft. 6 in. outside lengths.
• RGI MRL-8128: 8 ft. 4 in. outside width, in 12 ft. 4 in., 15 ft. 4 in. and 18 ft. 4 in. outside lengths.
• RGI MRL-10128: 10 ft. 4 in. outside width, in the same three lengths.

The iDEAL PSB-PMR1088-AK is the factory-finished alternative. It gives 10 ft. by 8 ft. by 8 ft. inside and is reversible: the sheet lists 10 ft. L x 8 ft. W or 8 ft. L x 10 ft. W, with optional door placement to the side or front, so it can be oriented two ways against a wall. It carries a 12 in. tube-axial fan at 1,429 CFM at 0.5 in. static pressure on a 1/2 HP three-phase 208-230/460VAC motor, a pre-hung 36 in. personnel door with viewing window, a deluxe control panel, bright white powder coat, and two LDPI fixtures listed UL and ETL for Class 1, Division 2. The fan and plenum chamber sit outside the room to keep noise down.

The eleventh model is not a prep station or a mixing room at all. The iDEAL PSB-AFOFB1388-3PH-230V-AK is an open face spray booth, the one enclosure in this category built for spraying: an A-frame with a 13 ft. wide by 8 ft. 6 in. high by 7 ft. 6 in. deep inside opening and a 24 in. UL listed Dayton tube-axial fan with spark resistant blades moving 7,983 CFM at 0.5 in. static pressure on a 2HP three-phase 230/460VAC motor. That is the higher airflow of the two iDEAL units; the RGI Mobile Prep-Station publishes more, at 12,900 CFM. It is the one item with published freight: $680 per unit to addresses in the contiguous 48 states. Alaska, Hawaii and remote or limited-access locations are excluded and may cost more, and orders over 2 units are quoted. Nothing in this category ships free.

What your building has to provide

Ceiling height disqualifies more buildings than anything else. All four full-size RGI prep stations stand 11 ft. 6 in. tall outside, and you need clearance above that for the stack and roof penetration. Mixing rooms are far easier: 8 ft. 6 in. outside on the RGI units, 9 ft. 4 in. on the iDEAL. RGI states a prep station can be freestanding, on structural steel supports, or suspended from the shop ceiling.

Power. Full-size prep stations are 3 hp three-phase at 208-230/460V, 60 Hz. The ECO PREP plenum is listed at 2 hp on its spec list, but the 10 ft. and 12 ft. configurations are listed as 3 hp in the model selector; confirm the motor with the factory drawing before sizing the circuit. The Mobile Prep-Station is 2 HP three-phase at 240V. The RGI mixing rooms are the accessible end at 1/4 hp on 120V, with the MRL-7128 sheet listing a single-phase or three-phase option. Both iDEAL units are three-phase as configured but list a single-phase option, so ask before ruling them out on service capacity.

Ducting is an option on eight of the nine RGI units, not an inclusion, and diameter varies sharply by model, which drives your roof penetration: 8 in. on the mixing rooms, 24 in. on the DELTA and STEALTH, 30 in. on the VECTOR, VECTOR T and ECO PREP. Each of those kits is two plain ducts, a service door duct, a roof flashing and a damper cap. The Mobile Prep-Station sheet lists no duct kit among its options; ask how the exhaust is run. The iDEAL mixing room uses a separately sold 8 ft. kit at 13 in. diameter (PSB-13DUCTKIT-8); the open face booth an 8 ft. kit at 24 in.

Compressed air. None of the 11 sheets specify a compressed air requirement for the enclosure itself; size your supply from the spray equipment you will use inside it.

Code and listings

RGI directs buyers to NFPA 33 and Chapter 24 of the International Fire Code for spray applications using flammable and combustible materials, and NFPA 86 and Chapter 30 of the IFC for curing and drying. RGI notes that many components and product lines are ETL and ETL-C listed, marks indicating compliance with North American safety standards including UL, NFPA and OSHA. Two options carry their own standards: the ECO PREP curtain walls meet NFPA 701 for fire retardancy, and the optional fire system for the Mobile Prep-Station is specified for installation per NFPA 17. Both iDEAL units state they meet or exceed applicable OSHA and NFPA 33 regulations, with UL listed fans and NEMA rated motors.

RGI also states that local requirements may vary from national codes and recommends consulting local authorities before purchasing. Air permits and fire marshal sign-off are local, and the answer in one county is not the answer in the next.

Model comparison

Prices shown are for the base configuration of each model: the shortest listed length, or in the ECO PREP's case the narrowest listed width. Longer lengths are priced separately. The STEALTH runs $26,000 at 24 ft., $29,000 at 27 ft. and $35,200 at 30 ft. On the RGI units, powder coat, controls and ducting are quoted separately; fire suppression is listed as an option on the three RGI mixing rooms and the Mobile Prep-Station. Both iDEAL units include the powder coat finish and the control panel.

Where the published sheets disagree

Plan floor space around the outside dimension, not the inside one.

• The RGI MRL-8128 and MRL-10128 tables list an inside working length 2 in. longer than the outside length (12 ft. 4 in. outside against 12 ft. 6 in. inside). The MRL-7128 table reads the other way, which is the plausible one. Confirm against the factory drawing.
• The 30 ft. STEALTH PREP is listed at 30 ft. outside length and 30 ft. 6 in. inside. Confirm before ordering that length.
• The ECO PREP spec list gives 4 ft. 6 in. of outside height and widths of 8 ft. 4 in., 10 ft. 4 in. and 12 ft. 4 in.; the model selector on the same page gives 4 ft. high and widths of 10 ft. and 12 ft. Confirm against the factory drawing.
• The ECO PREP spec list gives a 2 hp three-phase belt-drive motor, while the model selector lists 3 hp for the 10 ft. and 12 ft. configurations. Confirm the motor before sizing the circuit.
• The VECTOR T PREP is named and documented as a corner tower exhaust unit, but its airflow paragraph repeats the VECTOR's back wall wording. The model name and the tower filter assembly document are the reliable source.
• The RGI mixing room sheets list an 8 in. direct drive exhaust blower and a belt-drive motor in the same list. Confirm the drive type.

Frequently asked questions

Can I paint a whole car in a prep station?

No. RGI states on the five enclosed prep station sheets here that the amount of material sprayed shall not exceed one gallon in an eight-hour period. Those five are built to the EPA 6H Paint Rule for sanding, priming and limited painting. The one enclosure here built for spraying is the iDEAL PSB-AFOFB1388 open face booth, with a 13 ft. wide by 8 ft. 6 in. high by 7 ft. 6 in. deep inside opening and 7,983 CFM at 0.5 in. static pressure.

What is the difference between a paint mixing room and a prep station?

Size and purpose. A mixing room is a walk-in enclosure, 7 ft. to 10 ft. wide in the RGI families and 8 ft. by 10 ft. in the iDEAL, for mixing paint under ventilation. The four full-size prep stations are vehicle-sized bays, 14 ft. of inside width by 22 ft. 6 in. to 30 ft. of inside working length, where the car sits while it is sanded and masked. Two others are not enclosures of that kind: the ECO PREP is a 3 ft. long plenum box and the Mobile Prep-Station publishes no dimensions.

Do I need three-phase power?

For the prep stations, yes as configured: 2 hp or 3 hp three-phase. The RGI mixing rooms run 1/4 hp on 120V, and both iDEAL units list a single-phase option.

Is ducting included?

No. On eight of the nine RGI units ducting is a listed option, and the diameter runs from 8 in. on the mixing rooms to 24 in. on the DELTA and STEALTH and 30 in. on the VECTOR, VECTOR T and ECO PREP. The Mobile Prep-Station sheet lists no duct kit among its options. The iDEAL duct kits are sold separately.

Which prep station gives the most usable length?

The STEALTH and the DELTA both give the full 24 ft. of inside working length on the 24 ft. model, because the STEALTH exhausts through the floor and the DELTA through a side wall, while the VECTOR and VECTOR T give 22 ft. 6 in. If width is the constraint, the STEALTH is the one to look at first: 14 ft. 6 in. outside, two inches wider than the VECTOR at 14 ft. 4 in. and 22 in. narrower than the DELTA at 16 ft. 4 in., and it still gives the full 24 ft. of inside length. RGI notes the floor exhaust is what makes it wider, and its outside length runs 24 ft. 6 in.