How to iron on patch Step 1: Place the patch where you want it, preheat the iron to 240-300°F (120-150°C), you can place a cotton cloth over the patch before ironing. Step 2: Press iron from both sides for 30-60 seconds to make sure the hot glue melts and sticks well. Step 3: Finally, iron for 30 seconds from the front, mainly in the corners, to ensure a smooth surface. Step 4: After waiting for the patch to cool, check it, repeat the steps above for any areas that were not ironed. Of course, you can also use thread to sew the patch together if you want a permanent fixation patch. More details: Search "how to iron on patch" by GOOGLE.