Melting aluminium

[Gavj75]

Hello again to all.

I just have one simple question :

Can I use a peice of mild-steel tube with a bottom and handle welded on, as a make-shift crucible, to melt  aluminium in?

I've watched people on line recycling odd bits of aluminium and casting it into useful billets(if that's the right word) and thought I'd give it a try 

[Frosty]

Are you sure they were actually "usefull?" Just because someone on the internet melts found al and pours it into a piece of angle iron doesn't mean the aluminum is still any good. 

However, yes you can use a steel container to melt aluminum a couple times but the can will erode and the iron will contaminate the aluminum. You can buy a proper crucible for a few bucks and make a melter from brick and melt with charcoal briquettes. Look up the Gingery how to books, they lay it out step by step for all kinds of home shop build it, do it yourself projects. Heck half his projects require you cast aluminum like the lathe or mill builds. IIRC he even tells you how to select scrap depending on what kind of parts you wish to cast.

Ingot is the word you're looking for.  Amazon lists many sizes and types of crucibles running from $14. - $ hundreds. 

Frosty The Lucky.

[Smoggy]

In an atempt to clarify, billet and ingot.

If you are melting scrap aluminium to clean it of various detritus with a view to remelt at a later date, when you have enough good clean material, into a finished casting, typically done in the hobby foundry in uptruned angle iron molds or cupcake tins, they would be ingots.

If you are melting aluminium to cast into a solid form intended to then be machined, say a solid cylinder to be turned on a lathe to make maybe a candlestick, that would be a billet.

Frosty is assuming, quite reasonably, that you wanting to refine the scrap into ingots to later remelt for casting either billets or more complex cast items, ie bracket. pommel, etc.

[Steve Sells]

If you are melting for resale, DONT, they wont buy it, being a now unknown alloy, they prefer the original parts and an ingot has unknown content

A crucible can be made from a section of schedule 80 pipe and a solidly welded end cap for melting lead or aluminum. It will take a while longer to heat up. If careful small amounts of brass or bronze (under 10 lbs) can be melted in it.  While making crucibles is possible, the safety, time and effort invested makes sense to purchase commercial crucibles.

[ThomasPowers]

While it's a lot easier to store/transport scrap as ingots; as mentioned: you are out the time, fuel, consumables (everything in a foundry is a consumable---some things just last longer than others), and they pay less for homemade ingots.  If your foundry process are not topnotch you are usually degrading the metal each time it gets melted too. Doing a single melt/pour is generally better for objects you want to cast.

[BIGGUNDOCTOR]

If you are going through the process to melt the aluminum, have a project in mind and just cast it at the same time.  I wouldn't waste the time and money making an ingot, and then repeat the time and expense to cast a part later. And here you get paid more for non ingot aluminum scrap.

[Gavj75]

Thanx for all your info people. 

My motivation behind this was to end up with a billet( thanx Smoggy) which I can then turn in the lathe as I'm not satisfied with the drive wheel on my beltsander. 

I have everything I need to do this including lots of bits of scrap aluminium therfore, if it works out ok I'll save the forty or so quid it would cost to buy the stock material and have it delivered. 

[mutant]

Check out alloyave.com The guys there will steer you in the right direction. You you're planning on doing just a couple of melts, a metal crucible is fine. Casting a simple billet is pretty straight forward but you might want to add gates and a sprue - both help with metal flow and shrinkage.

-m