Reconditioning a large quantity of aluminium profiles

[hdv]

Hi all,

I got lucky and have gotten a large quantity of aluminium (aluminum) profiles for free. About a hundred varying in length between 1 and 2 meters. These are "plain" profiles with either square or single-lipped cross-sections, so it is not 8020 or something like that. I have been busy cleaning them up and now all dirt is gone I can see there is mostly minor damage to the surface of the profiles. I am thinking of trying to improve their looks a bit by either sanding or polishing, but am not really sure what would be wise.

Does anyone on the FOG have any experience with reconditioning aluminium? I am not looking a removing or reapplying the alu-oxide layer on the surface, just to get an even sheen as much as possible. I do have very high-grid Granat paper (used it to make acrylic glass transparent again), but am not sure that is the way to go. Would this be something for a Shinex? Or is there a better way to go about this?

I'd love to hear your thought on this!

 

[bertv]

Scotch Brite!

 

[Steve1]

I am pretty sure most aluminum extrusions are clear anodized at the factory.  Its extremely thin, but extremely hard.    You would have a very difficult time getting through the anodizing, and I don't think you would really want to.

So any dirt is likely just on the surface.    A strong laundry detergent (such as Tide) and a polymer pad (such as the green side of a Scotchbrite kitchen pad) is probably the most I would bother to invest in cleaning it.

 

[hdv]

[member=65451]Steve1[/member] : I know, that's why I wrote that I was not looking at removing that layer.

It's just that quite a few of the profiles have a slight discolouration that I could not remove with sweat and a green pad.

 

[Holzhacker]

I used my R090 to clean up a bunch of a aluminum a few years ago. Don't remember what cleaner I used. Used a finer grit 220,240 paper and then the buffing pads. Worked great.

 

[Cheese]

I'd forgo the sandpaper and just use Scotch-Brite™ pads. The sand paper increases the likelihood you'd break through the clear anodizing.

Using the RO 90 with some pads cut to size would be the easiest solution. I'd start out at a fine grit and then move progressively to a more coarse grit if necessary.

Scotch-Brite™ 7445, white pad, 1200+ grit
Scotch-Brite™ 7448, light gray pad, 600-1000 grit
Scotch-Brite™ 7447, maroon pad, 320-400 grit

 

[hdv]

Thanks. Bert also recommended using Scotch-Brite pads. I'll try that. Maybe they will do better than the green pads I took from the kitchen. They probably will. A pity it is so hard getting the 744x pads around here. I while ago I tried to get new white ones for applying Osmo and gave up in the end. I found some cheap knock-offs that at least could be delivered to my home.

 

[Svar]

Are you sure they are anodized? It would be unusual for structural aluminum, such as simple square bar to be anodized. A picture would help.

 

[hdv]

Sorry, can't make a photo of it right now. The sheen of the surface is a nice even grey, no shine to it at all. The places where it is scratched are gleaming with the colour of freshly polished metal. I am quite sure it is anodized, because when I lay it next to 8020 it has the exact same look to it. The cross-section of the profiles is 20x20 mm, so no structural alu.

 

[Packard]

Hi all,

I got lucky and have gotten a large quantity of aluminium (aluminum) profiles for free. About a hundred varying in length between 1 and 2 meters. These are "plain" profiles with either square or single-lipped cross-sections, so it is not 8020 or something like that. I have been busy cleaning them up and now all dirt is gone I can see there is mostly minor damage to the surface of the profiles. I am thinking of trying to improve their looks a bit by either sanding or polishing, but am not really sure what would be wise.

Does anyone on the FOG have any experience with reconditioning aluminium? I am not looking a removing or reapplying the alu-oxide layer on the surface, just to get an even sheen as much as possible. I do have very high-grid Granat paper (used it to make acrylic glass transparent again), but am not sure that is the way to go. Would this be something for a Shinex? Or is there a better way to go about this?

I'd love to hear your thought on this!

If it is not badly pitted and you have an anodizing shop nearby that is the best option.  They will clean the surface chemically and then anodize it.  Anodizing can be in clear or colors.  The finish penetrates the surface and not only  improves the look, it hardens the surface.  There will probably be a minimum lot charge for this, but it will keep the aluminum from oxidizing further. 

Black is nice and hides a bunch of surface problems.  Clear is super shiny.  The gold, red and clear aluminum finishes on Incra gages are all anodized.  The colors seem metallic because you are looking at a metal surface that has been colored.  The colors will not rub off, and the finish is as hard as the material itself.  Tiny scratches will still retain the color.  Deep scratches will expose the aluminum substrate.

 

[hdv]

Thanks! In the end I choose to not go the anodizing route, because I thought that was too costly for alu that I got for nothing and was not sure yet what I would do with. I put in a lot of elbow grease and got them to look quite nice. Not as new, but good enough to me.