Sealing Old Aluminum Sliding Windows (2025 Update)

Double pain replacements are my first choice, but with so many other fix-up jobs to do this summer, it would kill the budget to replace all of them. So we'll replace the 3 on the rainy/windy side of the house and leave the rest for next time.

The only thing wrong with them is that they leak all the way around -- around the edges, where the windows meet each other when closed or open. They are 50 year old aluminum frames, single pane, with no vinyl finish, but otherwise look like this...

The seals between the glass and the frame are OK. It's the aluminum-to-aluminum contact points that leak.

And while I'm asking... if I can seal them properly, the next thing would be any tips on painting them white or some other type finish so they match the new ones as closely as practical?

Thanks folks!

Bob

Guv,

What sort of seals, rubber, felt, et c.? I'd start looking for seals at the local glass shop. They'll have catalogs and advice at least. Google window seals.

Dave M.

might be best to install storm windows

Forget trying to find them online. Find a good bricks and mortar glass and window shop. Here in Kitchener it would be Reinharts. If it's available he'll either have it or know where to get it - and he'll know how to install it, and he's as reasonable as they come.

If you're getting air leakage around the sliders, then the problem is most likely that the weather stripping on the sliders is worn out or missing. My experience is that on sliding aluminum windows, there is only weather stripping on the vertical ends of the sliders, not at the horizontal tops and bottoms of the sliders.

One of the most common kinds of weather stripping used on older aluminum sliders was "Fin Seal" made by the Schlegle company:

If you can find any weather stripping like that on your windows, it's Schlegel Fin Seal, and you can buy it in different widths and pile heights at places that repair windows.

Aluminum windows usually look great without painting - once you paint, you have to keep it painted. Usually parts can be replaced on aluminum sliding windows to make them much more efficient, on my condo, built in 68, many years ago I put the best GILA window film on the glass, to reduce the extreme summer heat in my area, and the winter cold - gets down to about 30 F here occasionally. Have the window seals replaced on your windows, and use the best ones, that will last much longer and perform MUCH better - on my condo, the building has shifted a bit over the years, so as I rarely open my windows, I put sliding window locks on the bottom AND the top of the window, to hold the window frame securely against the window frame. On a very windy day today, I noticed my dining room window is rattling a lot, so that is the only window I need to remove when it is NOT windy, and replace weatherstripping, look at the rollers to make sure they are in place, perhaps put additional weatherstripping material in some places.

Look out for weep holes. Bugs had clogged up weep holes and melting snow sogged up under my window sill.

-- Vasos Panagiotopoulos panix.com/~vjp2/vasos.htm ---{Nothing herein constitutes advice. Everything fully disclaimed.}---

The only way to fix aluminum windows is to tear them out and replace them with quality vinyl windows. Argon filled LowE double glazed - or even triple, with insulated spacers. Tear out to frame - don't waste money on "inserts" They cost less, but not worth the saving.

Sometimes you might not want low-e glass . I have double glazed non-low-e windows on my house . Most of our windows are on the south and southwest sides of the house and we wanted the solar heat gain in the winter . Same with the french doors in the bedroom and dining room , double glazed south side and wanted the heat gain . All the other windows are small units and are shaded by trees during the hottest part of summer days so we don't get a lot of unwanted heat gain .

Low E works the other way too. Reversed it keeps the heat in - - - - cuts radiated heat LOSS while allowing the solar heat gain. Allows gain during the day while cutting loss at night.