Melting aluminum

You are fighting physics. The ratio of surface area to volume of your siding is far too high and as you melt it, it will form a very large proportion of various aluminium oxides which will settle out as a thick layer of dross on the surface of your melt. Melting it commercially they would plunge it into an already molten pool of aluminium so as to exclude the air. I found all this out when I started casting a couple of decades ago and was re-cycling beer cans. Produced as much dross as aluminium.
Now if you cut your siding into kiln sized pieces in a skillet, and filled the kiln with an inert gas you'd be fine !
AWEM

its better to melt it in a ceramic container. the aluminum is caustic when its molten and can eat through iron.

Pretty much what Andrew said, although I'd add that the vessel in which you'd do the melting wouldn't be a good choice. Molten metals have considerable solvent power------and will dissolve other metals when well below their melting points. That principle is used in assaying, where molten lead, reduced from litharge, collects metals that melt at much higher temperatures (platinum, for example) and includes them in the button. Platinum melts well over 3,000 degrees F, yet it is dissolved nicely by the lead at a much lower temperature.
If your objective were to reduce the aluminum for the sake of the exercise, a cast iron skillet would work, but you'd be contaminating the aluminum and altering its characteristics. You would end up with aluminum that is of poor quality. You'd also likely regret the stink and smoke that came from the finish on the siding.
Extruded aluminum, or rolled aluminum doesn't cast as well as aluminum alloyed for the purpose. If your objective is to use the resulting metal for casting, you'd be far better served to re-melt existing castings, which are alloyed appropriately and flow much better.
Right now, the scrap market is quite strong. If you have a recycling yard near, you might be pleasantly surprised to find your material is worth the trip. It's no retirement plan, but it should buy a nice lunch for you and the Mrs.
Harold

On Fri, 05 Oct 2007 06:23:14 GMT, with neither quill nor qualm, "Ivan Vegvary" quickly quoth:
Oh, sure. And the next time we hear from you, you'll be singing soprano after the Bobbitting job she did on you. She'll like that as much as you would like her cutting up the frozen turkey with your metalcutting bandsaw.
For a hoot, google up "resawed beans" on the Wreck (rec.woodworking newsgroup.) Then there was that Canuckistani guy who used his 20,000 RPM router for making whipped cream in the kitchen... ;)
Besides, I'm sure you'd have much more fun building your own propane-fired melting furnace.
-- Men never do evil so completely and cheerfully as when they do it from religious conviction. - Blaise Pascal

Hearing these stories always makes me thankful for the mother and wife that I have. We ate dinner on TV trays several times when I was in high school, because I had my S.U. carburetors all in pieces on the dining room table, and the smell of gasoline was too strong to eat there. And my wife never complained when I used our oven for bending wood, tempering steel, or curing industrial A-B cure epoxy.
You have to pick these important people in your life very carefully.
-- Ed Huntress

LOL! Sounds just like me, when I used my Dremel to froth up some milk for a cappuccino. Don't ask what happened. Just imagine the worst.
-- Jeff R. (flat white, that day.)

Harold,
Is that why the guy on the field's metal thread is saying the tin and bismuth will combine with the indium at 313F?
Wes

Well divorce works too but it is far more expensive than buying an oven for the shop. I guess I can consider that last batch of springs I did in the oven as a discount on the price of the divorce. ;)
Wes

Well, it might, but so slowly as to be irrelevant. I have melted aluminum in sawed off propane torch cans (20 ga?) without any noticeable thinning of the steel.
Bob

On Fri, 05 Oct 2007 09:33:20 -0400, with neither quill nor qualm, Wes quickly quoth:
I learned early on that people change in different ways and at different rates, so marriage doesn't stay together for very long. (Some exceptions are some of you old farts.)
By my 10th high school reunion, not ONE of the people I'd attended high school with who'd gotten hitched (during/since high school) was still married to the same person. Hell, even my parents got divorced (and remarried to each other a year later.) At age 14, I attended my grandfather's wedding. That was 8 years after my parent's wedding. (Oops, that was Grandpa's second marriage. Never mind.)
The cheapest way around a divorce is to shack up with a disclaimer clause for palimony (unless she supports YOU. ;)
-------------------------------------------- -- I'm in touch with my Inner Curmudgeon. -- ============================================

33 years married to my first wife, here. She's a keeper.
-- Ed Huntress

Thanks everybody!!!!
I think everybody. You've enlightened me on dross and saving my marriage. What a group.
Thanks again,
Ivan Vegvary (will be driving to the recyler)

molten aluminum eats cast iron really fast. I tried using a nice Lodge melting pot with molten aluminum, That was a bad idea.

Ed sez: "33 years married to my first wife, here. She's a keeper."
Good on you two, Ed ! I'm sure you are both equally blessed>
Bob Swinney

You didn't hear how long I've been married to my second wife.
Yeah, we're lucky. Interestingly, many of our friends have been married roughly as long. I guess that's why we're friends.
-- Ed Huntress

I've been real busy of late, and haven't followed that thread due to lack of time, but I feel that's the point to which he's alluding.
Molten metals are wonderful solvents of other metals. Think how mercury reacts to form amalgams. That's an excellent opportunity to see it happen at ambient temperature.
Harold

And I just celebrated the 30th anniversary with the 2nd Mrs. W.
Adding that to 14 years with the first one makes for a total of 44 years of married bliss.
No complaints, the dissolution of my first marriage was an perfect example of what "clutch" said earlier on this thread:
"I learned early on that people change in different ways and at different rates, so marriage doesn't stay together for very long."
And, the first spouse and I handled our divorce with courtesy and respect for each other and we still have a nonacrimonious relationship.
I'm fond of bragging that my first divorce (Which I hope will also be my only one.) is better than most marriages.
I think that swans are doing better than homo sapiens with regard to staying mated for life these days. I hear tell that 50% of all marriages in the last few decades have ended in divorce.
Jeff

I may have missed seeing it mentioned, but I'd iexpect that all that paint or whatever coating is on the siding would likely make one heaven of a stink when it burned off.
Jeff

I've had some success with stainless steel cookware (NOT from the kitchen, nor in the oven :) I assume this works because stainless protects itself with an inert layer of oxide, which even the aluminium can't eat.