Interthane 990
Aliphatic polyurethane · INTL · manufacturer-sourced
How long before you can recoat International (AkzoNobel) Interthane 990?
Short answer
Launch-ready plan
Weatherproof, in-water and underway are different dates
- Prepare and apply the Aliphatic polyurethane
- Keep it dry for the stated time
- Launch or use only after the stated cure
This product’s stated stages Quoted at 77°F
- Safe to touch1 hour 30 min
- Working time ends2 hours
- Safe to handle6 hours
- Ready for another coat6 hours
Worth noticing: Working time is only 2 hours; the next stated stage, safe to touch, is 1 hour 30 min.
Common mistake: Launching on the first dry day; most marine products need the immersion time stated.
Water-exposure plan
Splash, filling and continuous immersion are not equivalent
Splashes or dampness can use a different milestone.
Filling, launching or immersion requires the exact water milestone.
Use the Aliphatic polyurethane directions for polyurethane topcoat, boat topsides, and marine paint; do not infer immersion readiness from touch-dry time.
Time the marine cure
Your countdown
Stated times
- Working time ends2 hours
- Safe to touch90 minutes
- Safe to handle6 hours
- Ready for another coat6 hours
From International (AkzoNobel) data sheet · checked 2026-10-25. Anything not listed isn’t stated by the manufacturer.
Manufacturer website: international-yachtpaint.com
Conditions & fine print
- Stated conditions: 77°F (25°C)
- Drying, recoat and launch times change with temperature, humidity and film thickness. Follow the current data sheet and label for your boat and climate.
- Region INTL. Formulas can differ between countries; check your container.
- Working time ends: At 77°F (25°C).
- Safe to touch: At 77°F (25°C).
- Safe to handle: At 77°F (25°C).
- Ready for another coat: At 77°F (25°C).
- Entered from the cited manufacturer documentation. Check the current label for the exact formula and region. Report outdated information
- Actual results depend on preparation, thickness, ventilation, temperature, humidity, mixing and substrate.
Confirm this is your product
Closely named formulas, colors and regional versions can use different times. Match these details to your container before starting a countdown.
- Exact listing
- International (AkzoNobel) Interthane 990
- Variant
- Aliphatic polyurethane
- Region
- INTL
- Listed use
- polyurethane topcoat, boat topsides, marine paint
- Timed stages recorded
- tooling, touch, handle, recoat min
- Source checked
- 2026-10-25
Documentation: Technical data sheet · Issued 2/27/2019
Condition attached to the stated time: At 77°F (25°C).
About this product
A two-part aliphatic polyurethane topcoat. Its data sheet runs from 23°F to 104°F, so you can see a 60 hour hard-dry at 23°F fall to 3 hours at 104°F, while pot life goes from 26 hours to 45 minutes.
Using this specific product
International (AkzoNobel) Interthane 990 is listed here as the Aliphatic polyurethane version for polyurethane topcoat, boat topsides, and marine paint. For repairing marine or RV equipment, the useful question is not simply whether the surface looks finished—it is whether the exact next-action milestone shown above has been reached.
Before you start
- Confirm the package says Aliphatic polyurethane; related versions can use different timing.
- For polyurethane topcoat, boat topsides, and marine paint, pay particular attention to substrate preparation, temperature and water exposure.
- At 77°F (25°C).
How to check readiness
Check the immersion or launch milestone—not just touch-dry time. The data sheet gives a working pot life of 2 hours. Touch only a hidden edge first; a dry surface can conceal a soft layer underneath. Lift or move the item gently and avoid twisting the bond or pressing finished faces together.
Avoid this mistake
Launching too soon can expose an incompletely cured film continuously.
Compare with similar products
- Compare with Interlux Epoxy PrimekoteRecoat: 6–12 h there, 6 h here.
- Compare with Interlux Micron CSC HSRecoat: 6 h there, 6 h here.
Questions
How long before you can recoat this product?
International (AkzoNobel) states: The data sheet gives a working pot life of 2 hours. Conditions: At 77°F (25°C).. The data sheet gives a touch-dry time of 90 minutes. Conditions: At 77°F (25°C).. The data sheet gives a hard-dry time of 6 hours; it is the closest handling figure. Conditions: At 77°F (25°C).. The data sheet gives a minimum overcoat of 6 hours, with the maximum shown as extended. Conditions: At 77°F (25°C).. These are the manufacturer’s stated times, not a guarantee.
How much does cold weather slow Interthane 990?
A lot. The data sheet gives hard dry of 60 hours at 23°F, 24 hours at 41°F, 10 hours at 59°F, 6 hours at 77°F and 3 hours at 104°F. Working pot life is 26 hours, 12 hours, 4 hours, 2 hours and 45 minutes at the same temperatures.
How long do I have to work with this product?
International (AkzoNobel) states: The data sheet gives a working pot life of 2 hours. Conditions: At 77°F (25°C).. These are the manufacturer’s stated times, not a guarantee.
How long until this product is safe to touch?
International (AkzoNobel) states: The data sheet gives a touch-dry time of 90 minutes. Conditions: At 77°F (25°C).. These are the manufacturer’s stated times, not a guarantee.
How long until this product is safe to handle?
International (AkzoNobel) states: The data sheet gives a hard-dry time of 6 hours; it is the closest handling figure. Conditions: At 77°F (25°C).. These are the manufacturer’s stated times, not a guarantee.
What affects how long this product takes to dry or cure?
Drying, recoat and launch times change with temperature, humidity and film thickness. Follow the current data sheet and label for your boat and climate. Follow the product label for your conditions.