oxidised aluminium window frame

[scubabob]

my apologies if this has been asked before - i have looked. i have an aluminium window and the frame that the fixed and sliding window sits in is all, well crappy. it looks like it is oxidised and no amount of snading will get rid of it. i have just renovated the room and now it looks even worse. Any ideas on how to fix it short of replacing it, which i am prepared to do. Cheers

[bitingmidge]

What's snading?

Is it an anodised frame and it's just dirty, or is it completely powdery aluminium?

If there's oxidisation it usually starts out as pits.

The options are: Clean, sand and paint with a proper system designed for aluminium, or replace.

If it's only minor pitting, try polishing with somthing like Penetrol, but you'll have to do that regularly.

To avoid pitting, aluminium joinery should be washed with soapy water at about the same frequency that you clean your windows.


Cheers,

P

[scubabob]

the word "snading" is a technical term for a typographical error. actually it should read "sanding" sorry. didn't proof read too well. Thanks for the ifo by the way

[frontrunner]

Hello, though I am happy to get some help here as I was also looking for answers to the aluminum windows. At least there are some ways known to me now that can help me maintain them but for some time now I have been thinking if it would be a worthy choice to replace the current windows with the vinyl ones. Well the windows of my close friends who made them with vinyl do appear to be far more attractive than mine. But before going for the change I would like to know if they are indeed worthy of replacements?

[durwood]

To paint aluminium it has to be treated with a cleaner as is the case with all metals. These materials are called metal conditioners each metal has a specific one.

Steel rusts and is treated with Phosphoric acid before painting.

Aluminium is treated with Alodine,

As aluminium doesn't rust but oxidises the material is different, Its widely used in the aircraft industry where it is importaant to paint the surfaces properly ( marine also) Can't remember exactly the composition of Alodine but the aluminium is first cleaned with an appropriate method. New alumium only need to be solvent wiped and then washed over with metho.

In the case of your window a brass wire brush on a drill or better still one of those steel burrs in a drill or a drill bit sometimes or any thing you have which gets the metal clean sanding, grinding, scratching ???. Get the aluminium back to shiny without corrosion is the go. You should only consider replacement if the pitting is so deep you end up with holes in the surface trying to get to the good aluminium or this preparation takes so long to do you consider new the easier option.

Usually the aluminium windows are anodised or powder coated. I removed the powder coating with paint stripper which makes it easier to get the aluminium shiny all over. Often there is corrosion is under the rest of it but not showing yet. Anodising only changes the surface of the aluminium so there is no coating like paint as such.

You can then treat the aluminium with the alodine and prime and paint it. Depending on the brand you may have to dilute the material before use but just follow the instructions.

What really matters with aluminium when painting is to get good adhesion so a top primer is needed. Often in factory production the aluminium gets poor preparation such as people touching it with greasy hands or it isn't washed or dried properly so the final finish fails.The best primer for repair is epoxy it not only adheres well it offers great corrosion resistance. You can then paint with a suitable top coat.


If the aluminium is clean and shiny but rough because of the pitting you can fill the marks and smooth the surface with plastic filler such as used by on cars or in the building trade its called "builders bog". Fill the imperfections after the epoxy primer and before the top coat.

I live on a beach and use 2 pack top coats which are brushed on as is the primer. (easiest way to paint window frames) You should get more than 10 years out of a properly prepared surface. If things there are like they are here you will be changing the colour before you need to repair again for oxidation.