Smooth-Cast 45D
Fast urethane casting resin · US · manufacturer-sourced
How long before you can demold Smooth-On Smooth-Cast 45D?
Short answer
Cast-and-demold plan
Gel, demold and full cure are separate days
- Mix the Fast urethane casting resin to ratio and pour
- Wait for the demold time
- Sand or finish after full cure
This product’s stated stages Quoted at 73°F
- Working time ends5 minutes
- Demold30 minutes
Worth noticing: Working time is only 5 minutes; the next stated stage, demold, is 30 minutes.
Common mistake: Demolding early and leaving a soft, tacky casting that never fully hardens.
Project stage ladder
Demolding, handling, finishing and final use may occur at different times
For resin casting and hard plastic casts, identify which stage the stated to demold 30 minutes milestone actually unlocks. Earlier handling does not prove final cure.
Time demold and cure
Your countdown
Stated times
- Working time ends5 minutes
- Ready to demold30 minutes
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.
- Region US. Formulas can differ between countries; check your container.
- Working time ends: At 73°F (23°C).
- Ready to demold: At 73°F (23°C); cure time depends on mass.
- 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 Report outdated information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 Smooth-Cast 45D
- Variant
- Fast urethane casting resin
- Region
- US
- Listed use
- resin casting, hard plastic casts
- Timed stages recorded
- tooling, demold
- Source checked
- 2026-10-25
Documentation: Technical data sheet · TB code 070710-JR
Condition attached to the stated time: At 73°F (23°C).
About this product
Smooth-Cast 45D is a maker & casting resin product from Smooth-On, listed for resin casting, hard plastic casts. Its times are stated under: At 73°F (23°C). Its demold time of 30 minutes is shorter than 81% of the 95 maker & casting resin products here that list one.
Using this specific product
Smooth-On Smooth-Cast 45D is listed here as the Fast urethane casting resin version for resin casting and hard plastic casts. 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 Fast urethane casting resin; related versions can use different timing.
- For resin casting and hard plastic casts, pay particular attention to accurate mixing, mold material, mass and room temperature.
- At 73°F (23°C). At 73°F (23°C); cure time depends on mass.
How to check readiness
Check the casting itself for flex or tack before demolding. The technical bulletin gives a pot life of 5 minutes. 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
- Compare with Alumilite Amazing Clear Cast PlusDemold: 1 day to 2 days there, 30 min here.
- Compare with EcoPoxy FlowCastDemold: 3 days there, 30 min here.
Questions
How long before you can demold this product?
Smooth-On states: The technical bulletin gives a pot life of 5 minutes. Conditions: At 73°F (23°C).. The technical bulletin gives a cure time of 30 minutes. Conditions: At 73°F (23°C); cure time depends on mass.. These are the manufacturer’s stated times, not a guarantee.
How does Smooth-Cast 45D compare with other maker & casting resin products?
Smooth-On states 30 minutes for demold, which is quicker than the typical maker & casting resin product here (median 5 hours across 95 products). The quickest listed is Smooth-On Mold Star 14T at 9 minutes; the slowest is Smooth-On Crystal Clear 204 at 2 days.
What conditions do the stated times for Smooth-Cast 45D assume?
Stated conditions: At 73°F (23°C); At 73°F (23°C); cure time depends on mass. Baseline temperature: 73°F. Cooler, damper or thicker applications usually take longer.
Is there a faster Smooth-On maker & casting resin option?
Yes. Among the 94 Smooth-On maker & casting resin products listed here, Smooth-On Mold Star 14T states a shorter demold time (9 minutes versus 30 minutes).
How long do I have to work with this product?
Smooth-On states: The technical bulletin gives a pot life of 5 minutes. Conditions: At 73°F (23°C).. 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. Follow the product label for your conditions.