Henry

HE910 Asphalt Primer

Penetrating asphalt primer · US · manufacturer-sourced

Check your container: This countdown is for the Penetrating asphalt primer variant. Similar-looking versions may have different times.

How long does Henry HE910 Asphalt Primer take to dry?

Short answer

Set / hardened: 1 day after application.
Safe to touch: 3 hours after application.
Roof coatings and roofing sealants

Weather-window plan

Rain-ready comes long before fully cured

  1. Apply the Penetrating asphalt primer to a dry, clean roof surface
  2. Keep rain off for the stated period
  3. Allow foot traffic only at the stated time

This product’s stated stages Quoted at 68°F and 50% humidity

  • Safe to touch3 hours
  • Set1 day

Worth noticing: Safe to touch at 3 hours; set at 1 day.

Common mistake: Starting a coat when the afternoon forecast turns wet.

Roof coatings and roofing sealants

Coat timeline

Plan the next coat and final use separately

  1. 1
    ApplyUse the Penetrating asphalt primer directions and prepare for asphalt primer.
  2. 2
    Next coatUse the listed recoat milestone; do not substitute touch-dry time.
  3. 3
    Normal useWait for the applicable handling, water or cure milestone.

Plan around the weather

When did you apply the coating?
Conditions that affect drying
Where?
Thickness

Stated times

  • Safe to touch3 hours
  • Set / hardened1 day

From Henry data sheet · checked 2026-10-25. Anything not listed isn’t stated by the manufacturer.

Manufacturer website: henry.com

Conditions & fine print
  • Stated conditions: 68°F (20°C) and 50% relative humidity
  • Roof coatings need a dry surface and a rain-free window. Dew, fog, cold nights and thick coats all lengthen the times. Follow the current data sheet.
  • Region US. Formulas can differ between countries; check your container.
  • Safe to touch: At 68°F (20°C) and 50% relative humidity.
  • Set / hardened: At 68°F (20°C) and 50% relative humidity.
  • 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 Report outdated information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
Henry HE910 Asphalt Primer
Variant
Penetrating asphalt primer
Region
US
Listed use
asphalt primer
Timed stages recorded
touch, set
Source checked
2026-10-25

Documentation: Technical data sheet · Last Rev Date 02/15/2017

Condition attached to the stated time: At 68°F (20°C) and 50% relative humidity.

About this product

An asphalt primer whose sheet gives touch at 3 hours and set at 24 hours, with no recoat interval; it only says to let the primer dry thoroughly before coatings or adhesives. The test conditions are 68°F and 50% relative humidity.

Using this specific product

Henry HE910 Asphalt Primer is listed here as the Penetrating asphalt primer version for asphalt primer. For coating or sealing a roof, 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 Penetrating asphalt primer; related versions can use different timing.
  • For asphalt primer, pay particular attention to roof temperature, dew, rain in the forecast, film thickness and how many coats are needed.
  • At 68°F (20°C) and 50% relative humidity.

How to check readiness

Check that the surface is dry and that no rain or dew is forecast inside the stated window. Touch only a hidden edge first; a dry surface can conceal a soft layer underneath. The data sheet gives a set time of 24 hours.

Avoid this mistake

Rain resistance and walkable are earlier milestones than the full cure the roof system is rated for.

Compare with similar products

Keep going

Questions

How long does this product take to dry?

Henry states: The data sheet gives a touch time of 3 hours. Conditions: At 68°F (20°C) and 50% relative humidity.. The data sheet gives a set time of 24 hours. Conditions: At 68°F (20°C) and 50% relative humidity.. These are the manufacturer’s stated times, not a guarantee.

How long does Henry HE910 take to set?

The sheet lists touch in 3 hours and set in 24 hours at 68°F and 50% relative humidity. It gives no recoat interval, only to let it dry thoroughly.

How long until this product is safe to touch?

Henry states: The data sheet gives a touch time of 3 hours. Conditions: At 68°F (20°C) and 50% relative humidity.. These are the manufacturer’s stated times, not a guarantee.

What affects how long this product takes to dry or cure?

Roof coatings need a dry surface and a rain-free window. Dew, fog, cold nights and thick coats all lengthen the times. Follow the current data sheet. Follow the product label for your conditions.

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