I have Flexzilla garden hoses that have aluminum threaded connections/ends (YouTube 4:14).

If I leave the hoses connected together for a few weeks (tightened by hand), the connections often become seized. I can’t unthread them by hand and need to use a pipe wrench and a vise to get them apart. Or in extreme cases, soak the connection in motor oil for a few months to loosen the connection.

It’s a nuisance when the hoses seize like that. It happens with other garden hose brands too (again, aluminum connections, not brass).

Is there a way to prevent the hoses from seizing? For example, could I apply a certain kind of long-lasting lubricant to the threads?

  • 3
    Have you tried a rubber washer for a good seal while less firmly tightened? Jul 6, 2023 at 12:37

2 Answers 2


Aluminum is a relatively soft metal. When the threads go together, the aluminum can deform slightly so that it really 'locks on'. Depending on what other material the aluminum is fastened to, there can also be chemical reactions that actually do weld them together.

Your idea to apply some kind of lubricant is exactly what most people do. It's called anti-seize when you use it like this, usually sold with plumbing supplies. You can use grease, vaseline, special anti-seize compounds with graphite dust in them, pretty much anything that helps the threads go together smoothly and keep them apart as much as possible.

Another idea is to not use aluminum fittings. You can buy brass fittings to put on your existing hoses, and hopefully those would have less seizing.


Aluminium is relatively cheap to form these fine threads when compared to brass. The lightness of aluminium is not really a positive benefit.

Aluminium corrodes to a stable white oxide in the first few microns of its surface. This is why outside-aluminium looks dull and blotchy after some weather exposure. This surface tends to interact with the opposing thread, making it hard to undo.

One solution is to use aluminium parts with a coating electroplated on the outside. Anodised aluminium has a layer deposited on the outside which prevents the aluminium oxide from forming and binding the two threads together. It will wear off over time leaving bare silvery metal. Anodised aluminium tends to come in many colours, very rarely silver.

Paint does not work - it is generally too thick once hardened.

You can also use an assembly lubricant like copper grease, regular grease, or non-setting silicon gels (common in quality torches/flashlights) and they help protect O rings too.

Personally I'd just use brass fittings. Sure they cost 5 times as much, but last 10 times longer. I have brass joiners that have outlived their hoses multiple times and are approaching 3 decades old.

Another option is to use quick-connect fittings rather than thread-on fittings. These might be known as "Gardena fittings" but that's a trademark. Put the end on the hose once, and you never unthread it again ideally.

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