COLOUR / TOPCOAT · THE COLOUR
GP-1K BASECOAT COLORS (SOLVENT)
Single component basecoat with solid colors, metallic and pearl effect, made from weathering resistant resins, high quality, strong coverage power, and excellent adhesion power.
SCAN FOR THE FULL RANGE,
APPLICATION GUIDES & VIDEOS
germatech.com.au
TDS v2.3 · ISSUE 02.09.2026
SUPERSEDES —
REVIEW DUE 07.2028
Basecoat Colors 1 : Thinner 0.6-0.8
BY VOLUME
GRAVITY 1.2-1.4 mm · SUCTION 1.3-1.5 mm
HVLP 2.0 bar · RP 2.0-2.5 bar · CONV 3-4 bar
Solid colours: 2 wet coats. Metallics: 2 wet coats then a drop coat. Pearls:…
see the detail below
15-25 µm total
MAXIMUM the metallic paint film should not be thicker than 25 µm
At 23 °C, 5-10 minutes between coats*
*ADJUST FOR THE DAY'S TEMPERATURE
Allow 15-20 minutes air drying time before force drying*
SKIP THIS AND YOU GET SOLVENT POP
01SUITABLE SUBSTRATES
- Sanded and dried existing finishes, 1K or 2K primer
02SURFACE PREPARATION
Remove wax, silicon, and other contaminations with degreaser. The substrate must be sanded and cleaned before spray. (finish for colour: P500-P600 dry or P800 wet;
03MIXING
| PRODUCT | TEMPERATURE | REDUCER |
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| 1K Basecoat Colors | 15-30 °C | GP5107 |
| Ratio by volume | Basecoat Colors 1 : Thinner 0.6-0.8 |
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| Notes | Single component - no hardener. |
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BEFORE YOU START — THE SYSTEM IS THE PROCESSGerma-Tech abrasives and ancillary products are graded and tested for compatibility with this product and the process on this sheet — that control is what makes any problem on the job assessable and fixable. Once a non-Germa-Tech product has been used at any step, what actually touched the panel can no longer be verified, and issues that arise cannot be fairly assessed — by us or by anyone. Use the system through the whole process, and if something on this sheet does not fit the job,
talk to us before you spray. Refer to the
GERMA-TECH APPLICATION STANDARD.
04APPLICATION
| Gun — gravity feed | 1.2-1.4 mm |
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| Gun — suction feed | 1.3-1.5 mm |
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| Pressure — HVLP | 2.0 bar |
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| Pressure — RP | 2.0-2.5 bar |
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| Pressure — conventional | 3-4 bar |
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| Coats | Solid colours: 2 wet coats. Metallics: 2 wet coats then a drop coat. Pearls: 2 wet coats then a drop coat. (A light tack coat may be applied first if required.) |
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| Flash-off between coats | At 23 °C, 5-10 minutes between coats |
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| Flash-off before bake | Allow 15-20 minutes air drying time before force drying |
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| Dry film build | 15-25 µm total |
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| Maximum film build | the metallic paint film should not be thicker than 25 µm |
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05DRYING & CURING
No drying schedule is printed on the source sheet.
06COATING THICKNESS — WHERE THIS SITS IN THE STACK
THIS PRODUCT ▶
15-25 µm total
Sealer / wet-on-wet
25-35 µm
2K primer surfacer
50-80 µm
Body filler
shaped back — not film
SUBSTRATE
bare steel / prepared panel
FULL BUILD
170-270 µm of 300
Read it like the panel: substrate at the bottom, clear on top. Faded rows are the rest of the system at its normal build. See the Coating Thickness Guide.
MAXIMUM the metallic paint film should not be thicker than 25 µm — THE RED LINE ON THIS PRODUCT'S ROWPast that the film cannot get its solvent out: solvent pop, die-back, a soft film that never fully hardens, and cracking later. Modern polyurethane is a low-build system: less is better. Three thin coats do not fix what two correct coats did — they add microns and take the film past the limit. The red line on the FULL BUILD row is the 300 µm whole-panel ceiling — every layer added together.
07RECOAT & REWORK
| Recoat — this product over itself | RECOAT WINDOW — 1 hour: flash off between coats, then additional colour may be applied within 1 HOUR of the last coat at 20 °C. Past the window, the remedy is the same as missing the window to clear: scuff and re-apply colour. |
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| Over the previous coat | Sanded 2K primer → colour: apply the next coat within 24 HOURS of SANDING the primer. Past 24 hours from sanding, sand again before coating. Contamination-limited — the calendar governs, not the temperature. Epoxy → next coat: within the 2-hour unbaked window, or within 24 HOURS of SANDING; past that, sand again. GP-EP1 may be top-coated with direct gloss WET ON WET after 30 minutes minimum at 25 °C — no basecoat systems or single-pack topcoats unless fully cured. Wet-on-wet sealer → topcoat: THE FLASH-OFF TIME IS THE WINDOW — apply the next coat when the film is matt, 10-15 minutes at 25 °C. A sealer left past flash is a surfacer: sand before coating. |
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| The next coat over this | Basecoat → clear: allow 10-15 minutes air-dry, then spray clear at once — within 1 HOUR at 20 °C of applying the basecoat, all colours alike. Past 1 hour, scuff and re-apply basecoat before clearing. Cure-limited — heat shortens the window. |
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HOW EACH COAT BONDS — WHY EVERY WINDOW ON THIS SHEET CLOSESThe whole repair is designed as
one system applied within one overall time frame: the primer is dried and sanded, but from colour onward it is a concurrent, same-day process — and every window on this sheet exists to keep you inside it. Within its window the next coat fuses chemically with the film beneath; past it, the film has cured and adhesion must be made mechanically — abrade, degrease, recoat. Heat closes windows sooner: cure runs on temperature, not the clock. Straying from the timed system — jobs interrupted, held over, stretched — is where the problems start. Full explanation in the
GERMA-TECH APPLICATION STANDARD.
If in doubt, abrade. IF YOU MISS THE RECOAT WINDOWOnce the film has cured past its recoat window, do not put another coat straight over it — the new coat sits on the surface and lets go at the interface. Abrade the whole area first (P800 wet or a grey abrasive pad), degrease, tack off, then recoat.
08PHYSICAL PROPERTIES
| Coverage | about 3.6-4.2 m²/L in practice (6.5 m²/L theoretical at 20 µm) Estimate, not a measurement. Indicative coverage at 20 µm dry film thickness, assuming 100% transfer efficiency. Real-world coverage is lower — spray guns lose material as overspray. Allow 55-65% of the theoretical figure. |
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| Density | approx. 0.95 (metallics) – 1.27 (solid colours) (relative density, water = 1) — estimated from the Safety Data Sheet; not separately measured. Varies with the colour mixed. |
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| Equipment cleaning | Clean guns and equipment immediately after use with gun wash or a solvent cleaner. Never let mixed 2K product start to cure in the gun — once it kicks, no solvent will save it. |
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09STORAGE, SHELF LIFE & PACKS
| Storage life (unopened) | Up to 36 months unopened — SUBJECT TO correct storage: a cool, dry place below 20 °C, out of direct sun. Heat is the biggest killer of paint in the tin: stock stored or transported in hot vehicles, tin sheds, shipping containers or direct sunlight loses life fast whatever the date on the tin, and that is where most premature failures start. Storage life is an optimal guide, not a promise that survives a hot shed. |
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| Once the seal is broken | Once the seal is broken the clock starts, and how you store it sets the pace. Basecoat with reducer added: use within 24 HOURS, then discard. Unreduced basecoat not used the same day: airtight, in a cool dark place — 30 days, then discard.
All hardeners: 14 days once opened — then discard. Hardener is sealed without air; the moment air enters it starts to deteriorate. A part-used tin resealed tight lasts the 14 days; a loose lid does not. |
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| Storage | Store indoors in a cool, dry place below 20 °C, out of direct sunlight, with the lid sealed tight after every use. Never store or transport in heat — not in a tin shed, a shipping container, a hot van or a sunlit rack. |
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| Pack sizes | 1L · 3.75L |
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10PRODUCT CODES
| CODE | WHAT IT IS | PACK SIZE |
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| GP5107 | Reducer | 20LT |
11WHERE IT SITS IN THE SYSTEM
BARESUBSTRATE
›
EPOXYPRIMER
›
FILLER
›
2K PRIMERSURFACER
›
SEALERWET-ON-WET
›
COLOUR
›
CLEAR
The highlighted step is where this product sits in the repair. Ancillaries support every step.
12STANDARD NOTES — THE SAME ON EVERY SHEET IN THIS SET
- Below 15 °C, air drying at ambient temperature is not recommended — allow a full bake at 60 °C metal temperature. SN1 · ALL BAKEABLE SPRAYED PRODUCTS
- At low humidity, a flash-off of 2-3 minutes between coats helps achieve a smooth film. SN3 · ALL SOLVENT-SPRAYED
- Above 30 °C ambient, add Retarder Solvent or move to the slow reducer to avoid blushing — refer to the Retarder Solvent TDS. SN4 · ALL SOLVENT-SPRAYED
- In the overspray area between new and existing finish, apply Thinner SRA directly to achieve an invisible transition. SN5 · CLEARS & COLOUR
- Fisheyes during application: add 0.5-1% Anti Silicon to the remaining paint and respray the affected area. SN6 · ALL SOLVENT-SPRAYED
- Total coating thickness on the panel — every layer together — must not exceed 300 µm. Refer to the Germa-Tech Coating Thickness Guide. SN7 · ALL FILM-BUILDING
- Do not dry in direct sunlight — panel temperatures in direct sun can exceed 70 °C. Allow 24 hours or a full bake. SN9 · ALL BAKEABLE SPRAYED PRODUCTS
- Germa-Tech products are designed to work as a system — fillers, primers, basecoat, clears, hardeners, reducers, abrasives and ancillaries — each graded and tested for compatibility with the products and processes on this sheet. Performance is only assured within the system, and a fault is only assessable within it: once non-Germa-Tech product has been used in the process, what touched the panel can no longer be verified. SN10 · ALL PRODUCTS
- Apply basecoat to HIDING, not depth — solid colours: 2 wet coats; metallics and pearls: 2 wet coats then a drop coat; a light tack coat first is optional. Blacks normally hide in less. AVOID USING BASECOAT AS A GROUND COAT — use a tinted primer instead (Germa-Tech 2K primers tint up to 8% with 2K colour). Any ground coat forms part of the 2-3 coat maximum and the film build limit; it does not get its own allowance. Overloading causes delayed drying under the clear, leading to clear coat failures — delamination, or expansion cracking as the heavy film moves with heat, especially on blacks and dark colours. The teaching behind this — Application Standard, section 03. SN11 · BASECOATS
- *Flash-off times are measured at the stated temperature and MUST be adjusted for the day: colder than stated = LONGER flash, warmer = shorter. In winter, shops painting below 23 °C routinely under-flash — solvent is still in the film when the next coat lands. Below 15 °C, extended flash and air dry are not enough: bake the job. SN13 · ALL PRODUCTS WITH A FLASH-OFF
- FINISH FOR COLOUR — THE STANDARD GRADE. The last sanding pass before colour is P500-P600 dry (or P800 wet). METALLIC AND PEARL COLOURS REQUIRE P800, dry or wet — coarser scratches telegraph through the flake and show in the finish. Any coarser grits on this sheet are shaping or stripping stages, not the finish. SN16 · FINISH FOR COLOUR
Standard inclusions are controlled: each note applies to every product in its named set, enforced at build. They cannot drift onto some sheets and off others.
13PRODUCT-SPECIFIC NOTES
- The substrate must be sanded and cleaned before spray. (finish for colour: P500-P600 dry or P800 wet; metallic and pearl colours require P800)
- At temperature over 30 °C or in high humidity, it is recommended to use Retarder Solvent to avoid mottling.
- Because of the high transparency of metallic basecoat, good quality spray gun and professional spray techniques are required in order to prevent defects of mottling or poor metallic effects.
- To avoid problems of mottling or poor adhesion, the metallic paint film should not be thicker than 25um.
- Better effect could be achieved if the extra sliver powder could be removed with tack rag after the flash-off of each coat.
- After spray, allow 10-15 minutes air-drying time, then spray clear coat at once. Over long air drying time would affect the adhesion power.
AMBIENT TEMPERATURE — WHY EVERY TIME ON THIS SHEET MOVESEvery time on this sheet — flash-off, drying, pot life, the recoat window — is quoted at 20-23 °C, and every one of them moves with temperature, because the two things that set them, solvent evaporation and chemical cure, are both driven by heat. As a working rule cure rate roughly doubles for every 10 °C rise: at 30 °C the times run at about half; at 15 °C they stretch to nearly half speed. Judge by panel temperature, not air temperature — a panel in sun or fresh out of the booth is far hotter than the shed.
HOT WEATHER (above 30 °C): everything shortens. Flash-off comes down, pot life comes down, and the recoat window closes early. Move to the SLOW hardener and slow or extra-slow reducer so the film has time to flow and release solvent — spraying standard speeds in heat is the fast road to dry spray and solvent boil.
COLD WEATHER (below 20 °C): everything stretches. Flash-off gets LONGER — the most common winter mistake is coating over a film that looks flashed but has not released its solvent, which traps it under the next coat and comes back as fry-up, dieback or runs. Move to the FAST hardener, and extend every flash. Below 15 °C standard 2K cure effectively stalls — bake the job, or wait for heat. Cold does not extend the recoat window in proportion either: contamination, moisture and flash rust run on the clock regardless of temperature.
14GOOD TO KNOW — WHAT WE GET CALLED ABOUT
- Keep metallic film under 25 µm. Thicker gives you mottling and adhesion trouble.
- Over 30 °C or in high humidity, use Retarder Solvent to stop mottling.
- Tack off the loose silver after each coat has flashed.
- Clear it within 10-15 minutes of the last coat - long air drying kills the adhesion.
- Metallics are transparent: gun quality and consistent technique do the work, not extra coats.
15TROUBLESHOOTING
| DEFECT | WHAT YOU SEE | WHY IT HAPPENED | FIX |
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Thermal cracking over heavy basecoat | Cracking or crazing in the clear, typically appearing days or weeks after the job, almost always on blacks and dark colours, often after the vehicle has sat in the sun. | Too much total basecoat film — often from using basecoat as a ground coat under the colour. Any ground coat forms part of the 2-3 coat maximum and the film build limit; it does not get its own allowance. The overloaded basecoat dries late and keeps moving under the cured clear, and dark colours soak up heat — the heavy film expands and contracts at a different rate to the clear until the clear delaminates or cracks. It is a film-build failure underneath, not a clear coat fault. | There is no rescue coat — the affected panels must be sanded back past the failed film (usually to primer), refinished at correct film builds and properly flashed. |
Mottling | light and dark patches or streaks through a metallic or pearl, often following the direction the gun travelled | the metallic flake has not settled evenly - basecoat laid on too heavy, film over 25 µm, flash between coats skipped, gun pattern or pressure wrong, or the reducer too fast for a hot day | if the clear is not on yet, re-flash and lay a controlled final coat to even the flake; once cleared, sand back and respray the basecoat |
Colour float and dry silver | the metallic looks coarse, grey or milky against the standard, or loose silver sits proud in the film and shows through the clear | flake orientation is wrong - loose overspray silver left on the surface, a mist coat where none belongs, or the last coat applied too dry | re-flash and apply a controlled final coat before clearing; if it is already under clear, sand back and respray the colour |
Poor hiding | the undercoat, repair or featheredge is still visible through the colour after the stated number of coats | an inherently transparent colour, a primer colour too far from the topcoat, chasing coverage with extra thin coats instead of correct film, or basecoat over-reduced | on high-brilliance and poor-hiding waterborne colours add 5% WB3075 then WB3041PLUS; otherwise let it flash, correct the ground colour and rebuild - do not just keep stacking coats past the film limit |
Delamination and peeling | a coat lets go of the one under it - the film peels, flakes or lifts off cleanly in sheets, often starting at an edge or a stone chip | the surface underneath was not keyed or was not clean - missed degrease, wrong or no undercoat, sanding grit too fine or missed altogether, recoat window blown, or basecoat left too long before clear | remove all the loose film back to a sound layer, feather the edge, re-prime and rebuild the system properly |
Dry spray | a rough, dusty, low-gloss patch - usually on the far side of a long panel or around the edge of a blend | the atomised paint dries before it lands - gun too far off, air pressure too high, reducer too fast, or the shop running hot; on big panels the mist dries in flight | on 2K solids and clear, lay Thinner SRA over the overspray area straight after the coat to melt it in; once cured, sand the dry area back and refinish |
Dirt and dust inclusion | hard specks sitting in or under the cured film, felt with the back of the hand before they are seen | dust pulled in during application - panel not tacked off, static on plastic parts, dirty booth filters, contaminated air, overalls or gun, or crystallised additive poured straight from the tin | surface nibs come out after cure with P1500 working to P3000 then polish; anything embedded through the film has to be sanded and refinished |
AUSTRALIAN CONDITIONSAbove 30 °C ambient, move to the slow hardener and slow reducer and expect flash-off to shorten — dry spray and blushing are what a standard system gives you through a hot afternoon. Below 15 °C, air drying is not recommended: bake. In coastal and high-UV areas do not shortcut the epoxy step on bare metal.
16HEALTH & SAFETY
1K BASECOAT — THE CLEAR OVER IT IS THE ISOCYANATE STEPThis basecoat is single pack and contains no isocyanate. The 2K clear that goes over it does — when you clear the job, work to the clear's TDS and SDS and use
air-supplied respiratory protection. For the basecoat itself use respiratory, eye, skin and hand protection selected under AS/NZS 1715 and AS/NZS 1716.
Read the Safety Data Sheet before use. REVISION HISTORY
| VERSION | DATE | CHANGE |
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| v2.3 | 02.09.2026 | Reissued on the current Germa-Tech technical data sheet format. New in this issue: a quick-reference card, the hardener and reducer selection gauge, the coating thickness stack, the recoat-window recovery procedure, and a product-specific troubleshooting table. Bake schedules are now stated as metal temperature. |
17CARE OF THE COATING
CARE OF THE COATING — CONDITIONS OF THE WARRANTYFirst 12 weeks: hand wash only, pH-neutral automotive wash, soft mitt; no machine or brush washes, no wax, polish or cutting, no car covers; never leave fuel, brake fluid or water spotting to sit. No ceramic, glass/quartz coating or paint protection film for 12 months — sealing a maturing film traps solvent. Contaminants: bird and bat droppings, sap, insect residue, fuel and fallout etch the film — remove as soon as seen; etching left on is damage, not a defect. Cleaning: pH-neutral shampoo and fresh-water rinse; never dishwashing detergent, household cleaners, abrasive pads or strong solvents on the cured paint film; pressure washers fan tip, 30 cm minimum, never at edges or chips. Wash-down: passenger vehicles at least fortnightly (weekly in coastal, industrial or high-fallout exposure); fleet units weekly, more in heavy work, with a monthly walk-around and a wash-down register; any vehicle immediately after salt, fertiliser, chemicals, concrete dust, fuel or fallout; architectural and stationary work every 3 months (monthly coastal/industrial) with a maintenance register. Wax and polymer sealants may go on from 12 weeks, once cured. Breaches: inspect and touch up promptly — corrosion from any chip, scratch or breach, repaired or not, is never a coating defect.
18WARRANTY & FURTHER INFORMATION
TALK TO US — WE MEAN ITWe are always happy to talk to customers who contact us directly. If anything on this sheet does not fit the job in front of you — an unusual substrate, a tight timeline, a cold morning, a window you have missed — call before you spray, not after.
support@amproaustralia.com · germatech.com.au This sheet is read together with the GERMA-TECH APPLICATION STANDARD (terms, conditions of application and warranty) and the Coating Thickness Guide — both hosted with the data sheets and at germatech.com.au. Warranty is conditional on correct use of the product as described on this sheet, including the sanding steps and grits in its sanding guide, within the Germa-Tech system. The information in this data sheet is given in good faith and is based on laboratory and field testing. Ampro Australia has no control over the conditions under which this product is used, so the end user must satisfy themselves that the product is suitable for the intended application and conditions. All times are quoted at 20 °C and 50% relative humidity unless stated otherwise. This sheet supersedes all previous issues.
