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Slag is when the propellant accumulates unburned aluminum around the nozzle exit, suggesting an inefficient burn. This may be due to too low a combustion temperature to adequately burn off all the aluminum fuel. Solving this issues may require tinkering with the propellant ingredients.
Slag
Depressurization is a loss of pressure in the motor due to a leak or hardware defect, which can significantly decrease the impulse of our motor. Such defects may not be easily noticeable, which is why it's important to analyze post-firing photos for any signs of breakage. This could be caused from many factors, from sliced O-rings, failed RTV adhesion, hardware defects, etc. but is usually identified by burned grease around sealed areas.
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