I had this brilliant idea to put aluminum foil at the bottom of my oven while I cooked pizza at very high temperatures. I was hoping it would catch any toppings that fell off so I could quickly remove them and prevent smoke. The result is that the foil bonded to the oven and now I'm not sure how to get it off. Any chemicals or tools I should use in this situation?
That looks a lot like melted aluminum.
I'd use a solution of sodium hydroxide to dissolve it; probably won't even hurt the oven paint.
Easy Off Heavy Duty Oven Cleaner is NaOH based, so that'll probably work for you, and is easier to find than straight lye nowadays. Just follow the directions. If the aluminum is thick, you may have to do things twice.
Other brands of oven cleaner will likely work as well as long as they contain sodium hydroxide (lye). It will help A LOT for you people who need aluminum foil off your oven!
There was an article about How to Remove Melted Aluminum Foil from the Oven, but following several disappointing results by the participants, a user suggested a solution that was met with resounding success by those who tried it.
The author suggested an application of naval jelly (from the paint department at your local hardware store) as the solution that actually worked. Naval jelly is pink goop containing phosphoric acid that is used to remove rust from iron or steel, leaving a clean surface.
Essentially, you spread aluminum jelly over the aluminum, smear it around every few hours, leave it overnight, wipe clean and repeat process until the residue is gone. It might take a few days, but it is a gentle process with no fumes. The solution was was verified enthusiastically by several users in that conversation. You can read more about the process and reviews starting here:
Bonus solution: The original article also claims that the entire bottom plate of your oven can be replaced usually for less than US$30.00. Contact your manufacturer for a replacement part and guidance on installing it.
Unfortunately I can't post my pictures. But I recently did exactly what he did here and with worse consequences of foil. After reading everyone's post on several web sites, I tried the Heavy Duty Easy Off Oven Cleaner. After 4 applications and scraping with a "decal razor" scraper, I got nearly 97% of the foil off. I let the solution sit for an hour on each application. I was able to take the oven plate out of my oven and do this outside of the house.
Lining the bottom of an oven with aluminum foil or a foil liner is quite common and acceptable provided that the electric heating element is ABOVE the oven bottom, not below and that the liner is between the element and the bottom. This of course is not possible with a gas oven.
With that said, you could try scraping the foil off with a putty knife, if it is not interfering with the operation of the oven, leave it. Unsightly, but better than scratching up the porcelain finish of the oven. The oven bottom should be removable and you could order another and be back to pristine in a matter of a few days. Probably not what you wanted to hear. If you are thinking of ordering a new bottom pan, you might get a friend to try heating the stuck on aluminum with a portable propane torch to soften the aluminum and maybe it can be scraped off with little to no damage to the underlying oven bottom thus saving you some money.