# Aluminum Foil Melted in Oven



## goldsilverpro (Nov 7, 2008)

We hated our ceramic top stove and decided to trade it in for a new gas unit. I ran the self cleaning feature a couple of times and got everything sparkling. After cleaning, there was a 1 week delay in the delivery of the gas stove, so, to keep the old stove clean, I put a piece of heavy duty aluminum on the bottom of the oven. To make a long story short, the aluminum foil melted and bonded to the porcelainized finish. Here's what it looked like (28 September blog) on someone else's stove. Her comments are interesting, to say the least. It seems to be a common problem. You wouldn't think that a 400 F oven would melt aluminum. Evidently, the element is very close to the bottom plate and it gets up to the required 1220 F.
http://pinktangerine2.blogspot.com/2006_09_01_archive.html

This happened yesterday. About 3 hours before they were to pick up the old stove, I discovered the melted aluminum. They had given us $325 for it and I had to get rid of the Al to prevent screwing up the deal. So, I tried the easy things first, although, in the back of my mind, I knew that muriatic (or, lye) would be required, considering that I had only 3 hours to do it.

Scraping didn't work. Also, you scratch the finish. Four ought steel wool didn't work. I sprinkled it with salt and covered it with a towel saturated with vinegar and, later on, peroxide. Didn't faze it. I couldn't find strong enough lye that quick, so I went with muriatic.

The bottom plate on my stove had the same sort of depression as the photos in the link above. I diluted the HCl to about 60% and put it about 1/8" deep in the depression - and nowhere else - especially in the seams. I had to make a couple of small additions of straight HCl to keep it fizzing. I occasionally scrubbed it wet with 0000 steel wool. Besides abrasion, I thought I would create a cell between the AL and Fe to help the dissolving. Surprisingly, though, the steel wool didn't react. There must be some sort of coating on it. I ran the attic fan during the operation, of course. In about 45 minutes, all of the Al was dissolved. I sucked out most of the solution with a plastic turkey baster and rinsed the bottom plate well. I then made up a neutralizing baking soda solution and rinsed out the entire oven with it. After rinsing everything 5 or 6 times with water and drying, I heated up the oven to 400 deg. Zero smell. There was a slight discoloration in those areas that had had aluminum on it.

All the manufacturers warn idiots, like myself, against lining the bottom of the oven with Al foil, although they don't tell you why. The recommended (and best) solution is to replace the bottom plate - $20 to $30. The mfgrs. tell you not to use self cleaning if Al is stuck to the bottom plate.

Alfter reading 30 or 40 "solutions" for removing the aluminum on the internet, none of which are claimed to have worked, the method above, although a strong one, seems to be the only method to have worked, so far.

Some on the internet claim that the Al can't melt in an oven and say that it is only stuck from burned grease, etc. These are the ones who are just offering advice - it didn't happen to them - they haven't seen it. These people are 100% ignorant of the situation. We who have had the experience know that it melted.

Luckily, I didn't use the non-stick type foil that has teflon on it. According to the internet, it really causes problems.

I could had heated the oven a little, before adding the HCl. I just didn't want the fumes and the clean up. If push had come to shove, I would have heated it and and then cooled it a bit. I could also have used a brazing torch to slightly heat the metal. I didn't think about it, but a torch and steel wool or a scraper may have eventually oxidized it all and it could have been scraped up. Or, maybe, I could have laid a lot of solder wick on it and heated it up. Either of these would have left a thin film of aluminum. 

You gotta dissolve it or replace it.

Why didn't the Al oxidize? Too little air? It was totally bright any shiny. Reynolds says theirs is 98.5Al, the remainder being Fe and Si.


----------



## qst42know (Nov 7, 2008)

Bar Keepers Friend cleanser has oxalic acid in it and it does wonders on metal marks in a porcelain sink. I don't think you would have the same risk of corrosive fumes using oxalic acid, but that is a lot of aluminum you had there.


----------



## g_axelsson (Dec 1, 2008)

You probably managed to fuse the aluminum to the coating. It probably worked as a flux and lowered the melting point. Even if you had a relatively low temperature in the oven the foil worked as an insulation and the bottom was overheated.

I think that I would have used lye instead of HCl to avoid the fumes, lye is also passivating the iron and would protect it against corrosion. If my memory from school serves me it is very aggressive on aluminum.

Glad to hear that you found the solution to the problem in the end.... literally 

/Goran


----------

