Identifying aluminum

[kd0afk]

I plan on getting into aluminum casting but till I do, I've been stockpiling svarf, scavenged cylinder blocks, heat sinks and broken bike parts. Recently someone gave me a part of an old satellite dish and ive never felt anything like it. It's non magnetic but not stainless. And it is hard as heck and heavy.
My first casting will be a custom designed set of skateboard trucks. How can I tell what grade aluminum it is and is there some kind of strength test I can do on it?

View attachment 1442781764471.jpg

 

[Tin Falcon]

the simple answer if you want to cast aluminum. Use cast aluminum or old castings that are sound and not badly corroded. Or cast plate.
Tin .

 

[kd0afk]

These do look cast. Thanks. Making my own distinctive set of trucks is something I've wanted to do for a long time.

 

[10K Pete]

That ''heavier'' part is probably a zinc alloy. Very strong stuff. Will
really mess up an alum melt. Magnesium is also used, but less, usually
as an alloying agent in alum. Don't want that in your melt either!
There surely must be some simple test with acid or the like to sort
them out?

Pete

 

[Barnbikes]

Had a neighbor growing up that had a pile of old lawn mower decks behind his garage for a long time. One day he decided to melt them down and cast something. Not sure what they were made of but they disappeared as soon as the hit the heat.

 

[Journeyman]

Your satellite dish sounds like it is Zamak a zinc based alloy with about 4% aluminium and 2.5% copper. If you heat a small bit of it alongside a small bit of your aluminium stock it should melt much quicker Zamak melts at about 385 degC/725 degF whereas the aluminium will melt at about 660 degC/1220 degF. Zamak is fairly brittle and probably not much good for what you want to do. Definitely not a good idea to melt it into the aluminium although it could have some interesting properties!

Cheers
John

 

[goldstar31]

Again, you also have to watch things like some VW 'Beetle' castings which could be magnesium.

You could have an illuminating experience. Then, if things like rusty iron or steel gets into the pot, you can get rather warm.

Really, it is up to you but writing to the internet for help is not to be recommended after something happens. It is too late.

Be warned.

 

[gus]

I have used scrapped aluminum castings,extruded aluminum rods, engine casings etc. When charging into crucibles,please ensure scraps are bone dry with no water accumulation to eliminate explosion.


Absolutely to busybody spectators. All helpers must have experience melting and casting aluminum and protective gloves, helmet with face shield,protective clothings,heavy safety boots with leggings.Casting ladles must be robust. Molten aluminum burns is very bad and hard to heal fast.

Take care.

 

[kd0afk]

I have used scrapped aluminum castings,extruded aluminum rods, engine casings etc. When charging into crucibles,please ensure scraps are bone dry with no water accumulation to eliminate explosion.


Absolutely to busybody spectators. All helpers must have experience melting and casting aluminum and protective gloves, helmet with face shield,protective clothings,heavy safety boots with leggings.Casting ladles must be robust. Molten aluminum burns is very bad and hard to heal fast.

Take care.

And how will this help me identify the grade of aluminum?

 

[kd0afk]

Why can't I ever get a straight answer to my questions on these forums?

 

[goldstar31]

Why can't I ever get a straight answer to my questions on these forums?

Many of us come from very long and experienced backgrounds in all sorts of situations and give freely of our time and often quote from our own mistakes in a serious effort too impart knowledge- and I repeat- FREELY.

You are given the opportunity to accept or refute that advice but might I caution you to heed that there are many former contributors who no longer post here and elsewhere.

It may not be fashionable any more to say 'thank you' but it does help.

So off to other things, as my time is equally precious as others have concluded.

The forum is obviously worse but I feel that their reasons are valid.

Norman Atkinson

 

[kd0afk]

When someone answers my question I say thanks. So far, my question has remained unanswered.

 

[kd0afk]

Many of us come from very long and experienced backgrounds in all sorts of situations and give freely of our time and often quote from our own mistakes in a serious effort too impart knowledge- and I repeat- FREELY.

You are given the opportunity to accept or refute that advice but might I caution you to heed that there are many former contributors who no longer post here and elsewhere.

It may not be fashionable any more to say 'thank you' but it does help.

So off to other things, as my time is equally precious as others have concluded.

The forum is obviously worse but I feel that their reasons are valid.

Norman Atkinson

And what's funny is you didn't even answer this question let alone the original question I asked about aluminum identification.

 

[chucketn]

Basically, aluminum identification is a crapshoot. If you have a savy scrap dealer near you, they might identify your scrap with their electronic scan thing, don't know the proper name. Basically if it has been cast before, you can melt it and cast it again.
Processing swarf, however, is usually a waste of time, as it oxidizes quickly and produces lots of dross.
I do know that some aluminum castings contain magnesium, which can burn with a destructive fierceness that can be near impossible to extinguish. There are tests to determine the presence of magnesium, by seeing if you can ignite a small shaving, or if it fizzes in the presence of an acid.
Hope this helps. I recommend joining a casting forum like Alloy Avenue and learning how to identify you metal.
HTH.

Chuck

 

[kd0afk]

I didn't think it would be easy. Thanks to everyone that helped

 

[bazmak]

silly question for the forum really.You would need a metalurgy lab to identify alum alloys as there are so many and increasing all the time.No offence but its alum/alloy
:fan:

 

[10K Pete]

Thinking about this, I don't know how one could sort out different alloys
of aluminum but it may be possible to sort out the magnesium and zinc
rich alloys by testing specific gravity. It would be fairly simple to dry
weigh the chunk then immerse it and measure the water displaced. Might
keep the more adulterated aluminums out of your pile. ??????

Pete

 

[barnesrickw]

If only you could hit it with a grinder and read the sparks like steel.