YOU DON'T NEED A SOCK ON YOUR IRON BUT USING ONE WILL ELIMINATE MARRING ON YOUR COVERING. TRIM SOLVENT WILL ALLOW YOU TO APPLY TRIM WITHOUT HEAT WHICH IS THE PRINCPAL SOURCE OF BUBBLES.JUST WIPE A THIN COATING ON WITH A CLOTH OR SWAB AND APPLY TRIM DIRECT WITHOUT ANY HEAT. THE SOLVENT WILL ACTIVATE THE ADHEASIVE AND STICK IT DOWN. yOU STILL NEED TO WIPE ALL THE AIR OUT OR YOU WILL STILL GET SOME BUBBLES. THE PROBLEM OF DARK SPOTS SHOWING THROUGH THE COVERING IS A TOUGH ONE. I FIND THAT I NEED TO TRY TO USE A FILLER THATS IS AS NEAR THE SAME COLOR AS THE WOOD AS I CAN GET TO ELIMINATE THE SPOTS THAT SHOW THROUGH. SOMETIMES I USE SOME KIND OF COATING ON THE WOOD UNDERNEATH THE COVERING IN PREPARATION FOR THE COVERING TO GET AN EVEN COLORING ON THE SERFACE BEFORE COVERING. BALSA COLORED FILLER DOES PRETTY GOOD FOR THIS.