Identifying aluminum alloys?

I don't know every thing the rods will have to wait just now. But the two things to look for are the surface finish if it is fairly bright and will polish it will weld. If it is dull and when you bend a piece and it is stiff it won't weld. It will most likely be Dural this is a zinc aluminium alloy used in the aircraft industry.

I am sure if you would contact an ALCOA sales office or one of their manufacturing plants with your story they could help you

http://en.wikipedia.org/wiki/Duralumin

1st.-Line up an A.C.OUT,high -frequency Inverter TIG( Argon)Welding set_-

You can weld any Aluminium alloy after first removing scales mechanically Brushing.

You have only" afew SCRAP alloy Tubes".

Must be Same alloy-all!

So TIG weld . The same alloy will fuse very well.

You may or may not feed filler rods. By the way Dural is Cu+(not Zn+)

If you are welding material not thicker than 3mm - you can do with 200Amp welder.

A new machine can be had for ~$300 EX China--

Want reliable personal Contact? Ask me < mikemahant@hotmail.com>

BR

MM

Ok I hold my hands up Cu Not Zn. you'r correct. I was thinking of the fact that it contained a white metal. It can contain Mg. and or Mn. Even Si.

A new TIG for $300?!? Is it any good? Can you provide a link?

I've got MIG and gas, but if I could get a decent TIG for that cheap, I'd certainly do it.

Thanks.

Identifying the Copper element is the crucial point.

If you happen to be able to access a little HYDROFLUORIC ACID (nasty stuff, so gloves, mask, goggles), then put a drop (literally) on the degreased clean metal and leave for 30secs.

If it turns black, it contains copper and is probably DURAL;

If it turns white, it has no Cu. and is therefore NOT dural, and is easily and safely weldable.

Whatever result, wash off with copious clean water.

This sounds easy enough. Thanks.

If you happen to be able to access a little HYDROFLUORIC ACID (nasty stuff, so gloves, mask, goggles), then put a drop (literally) on the degreased clean metal and leave for 30secs.

I agree that this is a valid test, but may I respecfully suggest that HF Acid has absolutely no place in the home. It does not behave like other acids when it comes into contact with the skin. A concentrated HF burn the size of the palm of your hand could prove fatal if not treated very quickly by a doctor who knows what he is dealing with. A pin hole in your glove could result in the loss of a finger.

<I agree that this is a valid test, but may I respecfully suggest that HF Acid has absolutely no place in the home.>

We all are concerned , Andy

HF cuts Glass through in seconds!

Rubber Gloves will evaporate

Your nasal mucous membrane will be gone for good.

DOn't even try!

Thanks!

Any other, less deadly chemical test that'd help identify alloy?

5 minutes to any college Physics/Chemistry/Spectrosopy LAB.

Duralumin will have 5%Cu

Spectral lines(No HF,no Reagents )will glow even at 0.1%Cu.

Analyze anything Spectrosopically-painlessly-quantitativly-with a printout.

In minutes.

This may be doable. I live right in between the Indiana University and Rose Hulman campuses. At least Rose Hulman will be well-equipped.

thanks.

Pure aluminum (99.9 % ) or Al with 5 to 10 % Si or Al with 5 to 10 % Mg are all weldable using Al with 5 to 10 % Silica Electrode ( using SMAW process) or Filller wire (using AC TIG welding process).

since you have tubes the meterial could be pure Al or Al with silica and TIG ( 1.0 / 1.6 mm size) could be a better choice.

only make sure to clean the surface using SS wire brush or NAOH solution ( i.e., Sodium Hydroxide crystals available in any chemical shop and mix it with water to make a soution ) to remove AlO₃ layer failing which you will find it difficult to get a proper fusion during welding. Wash it with running water after using the solution , otherwise it may form white surface coating over the tubes.

MIG welding may punture ur tubes as the min. size of the filler metal will be of 1.20 mm size.

SRIDHAR

I HAVE BEEN IN THE SCRAP BUSINESS FOR 35 YEARS. i DON'T KNOW MUCH ABOUT WELDING BUT i CAN TELL YOU THAT THE ALUMINUM ALLOYED FOR WELDING WOULD BE ANY IN THE 5000 SERIES ALUMINUMS. RAILROAD HOPPER CARS ARE A 500O/6000 SERIES MIX