Stainless steel usually usually has a very oily surface. Even if it feels dry. I would think you need to wipe any stainless down with Isopropyl Alcohol before you mount anything to it. I have done plenty of vinyl on my stainless fridge. I even cut a thin lined box out and titled with script font"Menu" Very wispy tails on the font. And it has sticked for over 2 years without issue. Wipe it down with water and soap. Then a stainless steel wipe. The stailess steel wipe is loaded with oil. I believe stainless is also produced with alot of oil on the surface. You need something that will cut the oil off more then just soap and water.