Old Sticker Removal

 You know that bumper sticker you put on your old car, like 12 years ago, and has been cooked on to your fender for 12 years.  It seems like that would be a permanent bond, but it's not.  To liberate this old, cured adhesive is actually pretty easy.  In this example I have a piece of aluminum that has a product label on it.  I'm starting to surface finish the piece, and this label is in the way.  It's been on there for around 13 years.

There are chemicals that are specifically formulated for adhesive removal, and I hate all of them.  They are usually potent VOCs that are both flammable, and noxious.  So, what is the alternative?  Heat...  It is an electronic solvent.  How do you loosen something up at an atomic scale?  Heat...  It causes the atoms to expand, and you get mobility.  With mobility the adhesive gets gummy again, you can manipulate it again, and remove it easily.  My process is to use a heat gun, or hair dryer, and warm up the old sticker.  Then, in this case, I used a plastic scrapper to prevent gouges in the aluminum.  There is a residue of the adhesive left on the aluminum after scrapping the label, and adhesive off the part.  I use penetrating oil to remove the residue.  Then to remove the penetrating oil I'll use a degreaser like 409, or ammonia.  Now I can get back to the surface finishing...