Are you experiencing issues when working with polyurethanes (PU resins)? Here you can find solutions to the most common problems. We have clearly summarised the problem, the cause and the solution in an easy-to-read table.
Common problems with polyurethane casting resins
| Problem | Cause | Solution |
| 1. The polyurethane cures too quickly. |
Environment is too warm. |
Work at a lower temperature. |
| 2. The polyurethane contains too many air bubbles. |
a. Mixed too vigorously. b. Moisture in the polyurethane. |
a. Mix gently to minimise the formation of air bubbles. After pouring, place the mould in a pressure pot. b. Prevent moisture absorption by keeping containers sealed as much as possible. Place the A and B components separately in a vacuum chamber for sufficient time to degas and remove moisture.
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| 3. | ||
| 4. | ||
| 5. |
Common problems with polyurethane foam
| Problem | Cause | Solution |
| 1. The foam expands too quickly. |
Mixing too slowly. Mixing too much material at once. |
Mix quickly using a drill-mounted mixer. Polyurethane foam starts to expand after approximately 30–40 seconds. Do not mix more than you can process within 30 seconds. In practice, this is approximately 1 kg of A component and 1 kg of B component, mixed using a spiral mixer on a drill. |
| 2. The foam does not reach all areas of a cavity.
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Too few access holes.
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The foam is no longer fully liquid after a few minutes. Use an access hole every 30 cm to pour the foam into the cavity.
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| 3. | ||
| 4. | ||
| 5. |
Common problems with polyurethane-spray foam (Froth-Pak)
| Problem | Cause | Solution |
| 1. | ||
| 2. | ||
| 3. | ||
| 4. | ||
| 5. |
Have another issue?
If the problem you are experiencing is not covered in this article, please contact our product specialists. With their experience in working with polyurethane resins, they know exactly what to look out for and how to professionally resolve common issues. We are happy to provide tailored advice and think along with you. You can reach us on weekdays via email, phone, WhatsApp or through our contact form.
