Smooth-On

Free Form AIR

Air-dry epoxy putty · US · manufacturer-sourced

Check your container: This countdown is for the Air-dry epoxy putty variant. Similar-looking versions may have different times.

How long before you can demold Smooth-On Free Form AIR?

Short answer

Ready to demold: 1 day after application.
Maker & casting resin

Cast-and-demold plan

Gel, demold and full cure are separate days

  1. Mix the Air-dry epoxy putty to ratio and pour
  2. Wait for the demold time
  3. Sand or finish after full cure

This product’s stated stages Quoted at 73°F

  • Working time ends30 minutes to 2 hours
  • Demold1 day

Worth noticing: Working time is only 30 minutes to 2 hours; the next stated stage, demold, is 1 day.

Common mistake: Demolding early and leaving a soft, tacky casting that never fully hardens.

Maker & casting resin

Project stage ladder

Demolding, handling, finishing and final use may occur at different times

ShapeSetFinishUse

For sculpting, modeling, and putty, identify which stage the stated to demold 1 day milestone actually unlocks. Earlier handling does not prove final cure.

Time demold and cure

When did you mix and pour?
Conditions that affect drying
Where?
Thickness

Stated times

  • Working time ends30 minutes to 2 hours
  • Ready to demold1 day

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

Manufacturer website: smooth-on.com

Conditions & fine print
  • Stated conditions: 73°F (23°C)
  • Pot life and cure time shorten in warm rooms and with bigger batches. Follow the current technical bulletin for mix ratio, mixing and release agents. The chart is a summary.
  • Region US. Formulas can differ between countries; check your container.
  • Working time ends: Pot life depends on the thickness mixed.
  • Ready to demold: At 73°F (23°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 Report outdated information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
Smooth-On Free Form AIR
Variant
Air-dry epoxy putty
Region
US
Listed use
sculpting, modeling, putty
Timed stages recorded
tooling, demold
Source checked
2026-10-25

Documentation: Technical data sheet · Technical Data Chart (no revision date)

Condition attached to the stated time: Pot life depends on the thickness mixed.

About this product

The standard Free Form AIR putty, a slower sibling of AIR FAST. Its thickness-based pot life runs from 30 minutes at 1.5 in. to 120 minutes at 1/8 in., five times the AIR FAST spread of 6 to 10 minutes.

Using this specific product

Smooth-On Free Form AIR is listed here as the Air-dry epoxy putty version for sculpting, modeling, and putty. For casting resin, 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 Air-dry epoxy putty; related versions can use different timing.
  • For sculpting, modeling, and putty, pay particular attention to accurate mixing, mold material, mass and room temperature.
  • Pot life depends on the thickness mixed. At 73°F (23°C).

How to check readiness

Check the casting itself for flex or tack before demolding. The technical data chart gives a pot life of 30 minutes at 1.5 in., 60 minutes at 3/8 in. and 120 minutes at 1/8 in. Flex the mold away at one edge and stop if the casting bends, tears or remains tacky.

Avoid this mistake

Demold time is not necessarily full mechanical cure.

Compare with similar products

Keep going

Questions

How long before you can demold this product?

Smooth-On states: The technical data chart gives a pot life of 30 minutes at 1.5 in., 60 minutes at 3/8 in. and 120 minutes at 1/8 in. Conditions: Pot life depends on the thickness mixed.. The technical data chart gives a cure time of 24 hours. Conditions: At 73°F (23°C).. These are the manufacturer’s stated times, not a guarantee.

How does Free Form AIR compare with Free Form AIR FAST?

AIR lists 30, 60 and 120 minutes of pot life at 1.5 in., 3/8 in. and 1/8 in. AIR FAST lists 6, 8 and 10 minutes. Both cure in 24 hours at 73°F.

How long do I have to work with this product?

Smooth-On states: The technical data chart gives a pot life of 30 minutes at 1.5 in., 60 minutes at 3/8 in. and 120 minutes at 1/8 in. Conditions: Pot life depends on the thickness mixed.. These are the manufacturer’s stated times, not a guarantee.

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

Pot life and cure time shorten in warm rooms and with bigger batches. Follow the current technical bulletin for mix ratio, mixing and release agents. The chart is a summary. Follow the product label for your conditions.