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detection of alluminium

 

 
I have  some  metal  from  picnic table  whit glass 
2 interrogation
A  howto  verify  it is alluminium   maybe  magnnetic  ok  but  do you have  any other  method  like  acid  vinegar  or so
B   is it possible to  make a check  playing  dising  whit  sand blasst  on  these  kind  of  tenpered glass table  or  no  everything  exploded
 
jack 47 71
 
 

Not sure if it is a shape you could figure out its volume. If it is you could weigh it and see if that is the correct for that volume of material. Paul M
 

I assume by from a picnic table you mean it is a frame or part of a frame. If it looks like a cast part, then if it is magnetic, it is not aluminum. If it isn't magnetic, it could be aluminum or magnesium. Aluminum is 2.7gm/cm^3 and magnesium is 1.74 gm/cm^3, so if you can weight it and measure the volume (Archimedes), you can figure out which one it is.

you can also check out searching for "test aluminum versus magnesium"

Here is one example



On Tue, Sep 24, 2024 at 6:05 AM Jacques Savard via groups.io <jacquessavard=videotron.ca@groups.io> wrote:
 
I have  some  metal  from  picnic table  whit glass 
2 interrogation
A  howto  verify  it is alluminium   maybe  magnnetic  ok  but  do you have  any other  method  like  acid  vinegar  or so
B   is it possible to  make a check  playing  dising  whit  sand blasst  on  these  kind  of  tenpered glass table  or  no  everything  exploded
 
jack 47 71
 


--
Buffalo John
 

There are some chemical ways to test aluminum but require strong chemicals.  Calculating the density is a much safer way to go.
 

Perhaps Archimedes could assist.

On Tuesday, September 24, 2024 at 07:52:13 AM PDT, paul mcclintic via groups.io <cannontandem@...> wrote:


Not sure if it is a shape you could figure out its volume. If it is you could weigh it and see if that is the correct for that volume of material. Paul M
 

If you have concentrated nitric acid, that won't harm aluminum but will attack most other metals, including magnesium. Also, shaving of magnesium will burn brilliantly. (That's how they made flashbulbs).

Mike Taglieri 


On Tue, Sep 24, 2024, 9:05 AM Jacques Savard via groups.io <jacquessavard=videotron.ca@groups.io> wrote:
 
I have  some  metal  from  picnic table  whit glass 
2 interrogation
A  howto  verify  it is alluminium   maybe  magnnetic  ok  but  do you have  any other  method  like  acid  vinegar  or so
B   is it possible to  make a check  playing  dising  whit  sand blasst  on  these  kind  of  tenpered glass table  or  no  everything  exploded
 
jack 47 71
 
 

Aluminum will react with a strong base, ferrous metals won't. Probably the easiest to obtain is a drain cleaner; the kind you want will contain either sodium or potassium hydroxide. You'll probably need to scratch the surface (to break the oxide layer) under a pool of liquid. Magnesium is much less common due to cost & manufacturing difficulties.
 
Tempered glass MUST be annealed before attempting to cut it, otherwise the whole piece shatters into little cubes as soon as any part of the surface is breached. An easy way to identify it is with 2 polarizing filters - put the glass between the 2 of them & rotate one of them; tempered glass will show a, "Maltese" cross pattern, plain glass won't.
 
Roy
 

Dear Roy,
Many thanks for the Maltese pattern detection method for tempered glass.
Regards,
David (nr. Oxford, UK)


On 25 Sep 2024, at 00:56, Roy via groups.io <roylowenthal@...> wrote:


Aluminum will react with a strong base, ferrous metals won't. Probably the easiest to obtain is a drain cleaner; the kind you want will contain either sodium or potassium hydroxide. You'll probably need to scratch the surface (to break the oxide layer) under a pool of liquid. Magnesium is much less common due to cost & manufacturing difficulties.
 
Tempered glass MUST be annealed before attempting to cut it, otherwise the whole piece shatters into little cubes as soon as any part of the surface is breached. An easy way to identify it is with 2 polarizing filters - put the glass between the 2 of them & rotate one of them; tempered glass will show a, "Maltese" cross pattern, plain glass won't.
 
Roy
 

It isn't absolutely necessary to use two polarizers, if you have a pair of polarizing sunglasses.  Indirect light from the sky on a clear day is partially polarized, so just put them on and look at the sky through the glass.  Sky light isn't 100% polarized so the contrast between the light/dark regions won't be as dark as with a pair of polarizing filters.  But just about everyone has some polarizing sunglasses lying around.
 
I see this effect most often when driving since the car's windows are made with tempered glass.
 

I don't have one of these tabletops, but I had a thought. A cell phone has a polarizing filter. Would that also show the effect?

On Wed, Sep 25, 2024 at 9:52 AM Mark Kimball via groups.io <markkimball51=gmail.com@groups.io> wrote:
It isn't absolutely necessary to use two polarizers, if you have a pair of polarizing sunglasses.  Indirect light from the sky on a clear day is partially polarized, so just put them on and look at the sky through the glass.  Sky light isn't 100% polarized so the contrast between the light/dark regions won't be as dark as with a pair of polarizing filters.  But just about everyone has some polarizing sunglasses lying around.
 
I see this effect most often when driving since the car's windows are made with tempered glass.


--
Buffalo John
 

There acid to test types metal 
I never worry about it unless I am  welding or foundry work. 
Stainless is a different story because you know if 400 type and if a magnet sticks then 400 most machines it a bad day
 
Dave 
 
On Tue, Sep 24, 2024 at 06:05 AM, Jacques Savard wrote:

 
I have  some  metal  from  picnic table  whit glass 
2 interrogation
A  howto  verify  it is alluminium   maybe  magnnetic  ok  but  do you have  any other  method  like  acid  vinegar  or so
B   is it possible to  make a check  playing  dising  whit  sand blasst  on  these  kind  of  tenpered glass table  or  no  everything  exploded
 
jack 47 71
 
 

Try melting a piece of it?  Steel and Al have very different melting temps.
 

"Try melting a piece of it? Steel and Al have very different melting temps."

Steel would be easy. He's trying to tell aluminum from magnesium.

Mike Taglieri 


On Thu, Sep 26, 2024, 6:49 PM MikeK via groups.io <upand_at_them=yahoo.com@groups.io> wrote:
Try melting a piece of it?  Steel and Al have very different melting temps.

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