Final answer:
Porosity in joint surfaces caused by moisture can be prevented by using appropriate sealants, which increase heat transfer and protect the surfaces.
Step-by-step explanation:
Porosity caused by excessive moisture on the joint surface can be prevented by using appropriate sealants that not only help in preventing sticking but also increase heat transfer by filling in gaps and increasing the contact surface area. These sealants ensure that the joint surfaces remain dry and protected from moisture, which can otherwise lead to porosity issues in materials like metals or plastics used for making artificial joints. The correct application of sealants contributes to the longevity and performance of joints, whether in construction or in medical devices like artificial joints which often have very small coefficients of friction and require a glassy surface for optimal function.