What is the maximum acceptable time to wait before the pour begins in the thermite process?

In the thermite process, timing is critical for the successful execution of the weld. The maximum acceptable time to wait before starting the molten metal pour is important to ensure the integrity of the weld joint. Typically, it is recommended that the pour occurs no later than 1 minute and 30 seconds after the completion of the reaction, as this allows for adequate temperature retention and melting of the thermite mixture while minimizing heat loss.

Delaying beyond this time frame can result in a decrease in the molten metal’s heat and fluidity, increasing the risk of incomplete bonding at the weld interface. The choice of 1 minute 30 seconds represents a balance between ensuring that the thermite reaction remains effective and practical considerations in the welding process. Factors like ambient temperature, wind, and materials also influence how quickly the pour must be initiated, emphasizing the importance of following this guideline to ensure successful thermite welds.