Plasti-Paste
Urethane plastic · US · manufacturer-sourced
How long before you can demold Smooth-On Plasti-Paste?
Short answer
Cast-and-demold plan
Gel, demold and full cure are separate days
- Mix the Urethane plastic to ratio and pour
- Wait for the demold time
- Sand or finish after full cure
This product’s stated stages
- Working time ends8–10 minutes
- Safe to handle1 hour 30 min
- Demold1 day
Worth noticing: Working time is only 8–10 minutes; the next stated stage, safe to handle, is 1 hour 30 min.
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 casting and prototyping, 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 ends8–10 minutes
- Safe to handle90 minutes
- 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.
- Safe to handle: 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 Report outdated information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 Plasti-Paste
- Variant
- Urethane plastic
- Region
- US
- Listed use
- casting, prototyping
- Timed stages recorded
- tooling, handle, 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
Plasti-Paste is a urethane plastic on Smooth-On's technical data chart, listed with a pot life of 8 to 10 minutes and a cure time of 24 hours. This page uses only the chart values; mix ratio, hardness and release details come from Smooth-On's product bulletin.
Using this specific product
Smooth-On Plasti-Paste is listed here as the Urethane plastic version for casting and prototyping. 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 Urethane plastic; related versions can use different timing.
- For casting and prototyping, 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 8 to 10 minutes. Lift or move the item gently and avoid twisting the bond or pressing finished faces together. 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 Formlabs Grey Resin V5Handling: 30 min there, 1.5 h here.
- Compare with Anycubic Standard Resin V2Handling: 5 min there, 1.5 h here.
Questions
How long before you can demold this product?
Smooth-On states: The technical data chart gives a pot life of 8 to 10 minutes. Conditions: The chart gives no temperature.. The technical data chart gives a handling time of 90 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 Plasti-Paste compare with others in its line on the chart?
On Smooth-On's technical data chart, Plasti-Paste lists a pot life of 8 to 10 minutes and a cure time of 24 hours. Its closest chart companion here, Feather Lite, lists a pot life of 8.5 minutes and a cure time of 2 hours.
How soon can Plasti-Paste be handled after pouring?
The chart lists a handling time of 90 minutes and a cure time of 24 hours for Plasti-Paste, with a pot life of 8 to 10 minutes. Handling is the earlier milestone; the chart does not give a temperature for either.
How long do I have to work with this product?
Smooth-On states: The technical data chart gives a pot life of 8 to 10 minutes. Conditions: The chart gives no temperature.. These are the manufacturer’s stated times, not a guarantee.
How long until this product is safe to handle?
Smooth-On states: The technical data chart gives a handling time of 90 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.