Smooth-Sil 936
Smooth-Sil · US · manufacturer-sourced
How long before you can demold Smooth-On Smooth-Sil 936?
Short answer
Cast-and-demold plan
Gel, demold and full cure are separate days
- Mix the Smooth-Sil to ratio and pour
- Wait for the demold time
- Sand or finish after full cure
This product’s stated stages
- Working time ends1 hour
- Demold1 day
Worth noticing: Working time is only 1 hour; the next stated stage, demold, is 1 day.
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 mold making, identify which stage the stated to demold 1 day milestone actually unlocks. Earlier handling does not prove final cure.
Time demold and cure
Your countdown
Stated times
- Working time ends1 hour
- 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: Not stated in the data sheet
- 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; read the product's technical bulletin before you pour.
- Region US. Formulas can differ between countries; check your container.
- Working time ends: The chart gives no temperature.
- Ready to demold: The chart gives no temperature; its cure column is the last time value in each row.
- 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 Report outdated information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-Sil 936
- Variant
- Smooth-Sil
- Region
- US
- Listed use
- mold making
- 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: The chart gives no temperature.
About this product
Smooth-Sil 936 is a platinum-cure silicone rubber on Smooth-On's technical data chart, listed with a pot life of 60 minutes and a cure time of 24 hours. Its pot life is the longest in its group. This page uses only those two chart values; mix ratio, hardness and release details come from Smooth-On's product bulletin.
Using this specific product
Smooth-On Smooth-Sil 936 is listed here as the Smooth-Sil version for mold making. 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 Smooth-Sil; related versions can use different timing.
- For mold making, pay particular attention to accurate mixing, mold material, mass and room temperature.
- The chart gives no temperature. The chart gives no temperature; its cure column is the last time value in each row.
How to check readiness
Check the casting itself for flex or tack before demolding. The technical data chart gives a pot life of 60 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, 1 day here.
- Compare with EcoPoxy FlowCastDemold: 3 days there, 1 day here.
Questions
How long before you can demold this product?
Smooth-On states: The technical data chart gives a pot life of 60 minutes. Conditions: The chart gives no temperature.. The technical data chart gives a cure time of 24 hours. Conditions: The chart gives no temperature; its cure column is the last time value in each row.. These are the manufacturer’s stated times, not a guarantee.
How does Smooth-Sil 936 compare with its siblings in the same line?
On Smooth-On's technical data chart, Smooth-Sil 936 lists a pot life of 60 minutes and a cure time of 24 hours. Within the Smooth-Sil group the shortest pot life is Smooth-Sil 945 (25 minutes) and the longest is Smooth-Sil 936 (60 minutes); cure times run from Smooth-Sil 933 Flame Out (6 hours) to Smooth-Sil 935 (24 hours).
How long after the pot life ends does Smooth-Sil 936 take to cure?
The chart gives a pot life of 60 minutes and a cure time of 24 hours. If the cure clock starts at mixing, that is about 23 hours after the pot life ends. The chart does not state a temperature for these values, so treat that gap as a planning number, not a promise.
How long do I have to work with this product?
Smooth-On states: The technical data chart gives a pot life of 60 minutes. Conditions: The chart gives no temperature.. 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; read the product's technical bulletin before you pour. Follow the product label for your conditions.