U-POL Rapid System Primer UP6303, 2K High Solids, Gray, 1 US Gallon
U-POL Rapid System Primer UP6303, 2K High Solids, Gray, 1 US Gallon
SKU:UP6303
U-POL's rapid-cure 2K high-solids primer surfacer. It sands in 55 minutes at 70°F air dry, or 10 minutes at 140°F, and one activator covers every shop condition from 60 to 85°F.
- Primer : activator : reducer
- 4:1:1
- Sandable at 70°F
- 55 min
- Sandable at 140°F
- 10 min
- HVLP tip
- 1.6–1.8 mm
Faster to sand, one activator
- Rapid cure. Dust-free in 20 minutes and sandable in 55 at 70°F without a bake.
- One activator. Rapid System Activator is the only hardener, for all conditions from 60 to 85°F.
- High build. 2–3 wet coats for 2.95–3.95 mil of dry film.
- Goes under both. Topcoat directly with most solvent or waterborne basecoats and solid colors.
Goes over
- Original paint, sanded P220–320
- Mild steel and e-coat (bare steel sanded P180)
- SMC, fiberglass and U-POL polyester fillers, sanded P220
- Aluminum, zinc and galvanized, with U-POL recommending ACID#8 etch primer first
Keep activated and unactivated apart. U-POL says never pour mixed primer back into the can, and don't use it past its 45–60 minute pot life.
Mix and spray
- Mix 4 parts primer, 1 part Rapid System Activator UP6401 and 1 part Rapid System Fast Reducer UP6701, by volume.
- Check viscosity: 25–30 seconds DIN 4. Pot life is 45–60 minutes at 70°F.
- Spray with an HVLP gravity gun, 1.6–1.8 mm tip, at 25–29 psi.
- Apply 2–3 wet coats, flashing 10 minutes between coats.
- Air dry 55 minutes at 70°F, or flash 15 minutes and bake 10 minutes at 140°F. Sand dry P400–P600 or wet P600–P800.
Tech specs
| Part number | UP6303 (1 US gal); UP6301 is the quart |
|---|---|
| Color | Gray |
| Mix ratio | 4:1:1 with UP6401 and UP6701 |
| Pot life, 70°F | 45–60 min |
| Spray viscosity | 25–30 s DIN 4 |
| Gun | HVLP gravity, 1.6–1.8 mm, 25–29 psi |
| Coats | 2–3 wet coats, 2.95–3.95 mil dry |
| Dry, 70°F | Dust-free 20 min, sand 55 min |
| Dry, 140°F | Sand after 10 min |
| Coverage | About 285 ft²/gal (theoretical) |
| VOC, as applied | 3.78 lb/gal (453 g/L) |
| Shelf life | 2 years at 40–75°F |
Shipping options
| Standard | $15 · 5–9 business days |
|---|---|
| Express | $49.99 · 2–5 business days |
| Overnight | $199 per gallon · 1–2 business days |
Why the price jump? This primer is regulated hazmat (UN1263, paint). Faster service means shipping it as declared dangerous goods: certified packaging, hazmat paperwork and carrier surcharges on every gallon. Order ahead and standard ground keeps it cheap. Need it rushed? Contact us before checkout and we'll confirm the fastest legal option.
Related
FAQ
What's the mix ratio?
4:1:1 by volume: primer, Rapid System Activator (UP6401 or UP6425) and Rapid System Fast Reducer (UP6701).
When can I sand it?
After 55 minutes at 70°F, or 10 minutes at 140°F panel temperature.
Can I use a different hardener?
No. U-POL says it's only compatible with the Rapid System Activator and Fast Reducer.
Can waterborne base go over it?
Yes. U-POL says it can be topcoated directly with most solvent and waterborne basecoats.
What gun setup do you recommend?
HVLP gravity with a 1.6–1.8 mm tip at 25–29 psi, 2–3 wet coats.
Manufacturer documents: UP6303 TDS (PDF)U-POL product page
Regular price
$123.40
Regular price
Sale price
$123.40
Shipping calculated at checkout.
Quantity
Couldn't load pickup availability
- Ships in 1–2 business days from Eugene, OR — solvent-based items ship ground only
- Free ground shipping over $425 · $9.99 under
- 30-day returns on unopened, resalable items
In stock
Technical details
General
- Part number
- UP6303
- Brand
- U-POL
- Product type
- Primers & Sealers
U-POL Rapid System Primer UP6303, 2K High Solids, Gray, 1 US Gallon
$123.40