I received a tumbler as a gift. It is a powder-coated stainless steel tumbler but has a glitter vinyl(?) decal or transfer placed on the tumbler. I am afraid that even with handwashing, the decal will wash off so I would like to use something to seal it. I do not know whether to use an epoxy or resin or something else? I also would like to know the specific name or brand of whatever I need to purchase. Thanks in advance!