What is the main precaution for using solvent-removable penetrants?

The correct approach when using solvent-removable penetrants is to carefully regulate the amount of solvent applied. Excessive solvent can dilute the penetrant, compromising its effectiveness in identifying defects or discontinuities in materials. Applying too much solvent can also lead to incomplete removal of excess penetrant, which may affect the subsequent inspection process and lead to inaccurate results.

Using no solvent at all is not practical for this type of penetrant inspection, as solvents are integral to this method. Similarly, repeatedly applying solvent could cause oversaturation, while heating the solvent before application is not a general requirement and may introduce additional risks, such as increased volatility or improper application conditions. Thus, controlling the amount of solvent used is crucial to ensuring the integrity and reliability of the inspection process.