Why are my aluminium window frames crumbling?

[Jules2023]

 

 

 

About 6 weeks ago I was window cleaning and noticed some soft spots in my coated aluminium window frames, which appeared to be crumbling and some clear silicone looking substance behind. Since then it has dried and shrunk and can see right through to the wall cavity. House (and assuming windows) is about 27yo, this window is on exposed wnw wall, but have the same thing on a sliding door frame on sheltered opposite side of house.

Has anyone seen this? I read about how mortar can react with aluminium, and the damage is certainly in line with mortar joints. Any recommendation for a fix? I'm guessing at least some expanding foam?

[EricL]

Hello @Jules2023 

It might be necessary to push the silicone into the gap by using a Pro Renovator 38mm Plastic Scraper. Once you've placed a bead on the gap, use the plastic scraper to push it into the gap as much as possible. Hopefully by covering the edge of the aluminium the reaction will stop.  

If you need further assistance, please let us know.  

Eric

[Gordon2024]

I also have this issue, is there something else that can be used to neutralise the corrosion? I’m not sure I like the idea of nitric acid. I slid a metal scraper between the aluminium and brickwork to free up any obstructions, then cut some strips of black plastic to slide between the frame and the brickwork. I gave it a good soaking with wd40 to remove any moisture, but before I seal it all up with silicone or expanding foam, is there something else I can squirt in there to neutralise any corrosion that may develop in the future?

[EricL]

Hello @Gordon2024, 

Welcome to the Bunnings Workshop community. It's sensational to have you join us.

If you've read the suggestions offered, I think the best one is the use of neutral silicone as it will cover the surface of the aluminium and prevent it from being exposed to more contaminants. The only other recommendation that was not offered was the use of paint. Using a primer and topcoat on the damaged section will also seal the aluminium.

If you have any other questions we can help with, please let us know.

Eric

[R4addZ]

Hi @Jules2023 

There is actually special filler for Aluminium and that really is what you should use. It's formulated not to react with the aluminium and would act as a barrier between the metal and the wall. Bunnings may be able to order it in for you (I don't think they stock such a specialist item). This is the type of product I mean....

https://www.swiftsupplies.com.au/aluminium-repair-stick