I prevent it but spraying a bit of the acetone into the tip after use.
And the screw is on the Pistole (the wheel at the rear end, looks a bit different on mine than on OPs photo but same principle).
In theory the acetone is not even needed because it has a ball bearing tip that is airtight and that prevents the drying but I never tested the concept.
Iconoclast@feddit.uk 2 months ago
The foam gun seals at the very tip of the nozzle. Once you attach a foam bottle, the entire gun effectively becomes part of the pressurized bottle, and you can store it like that for months - but probably not years. However, if you set a reminder a couple times a year and spray some of the foam out from the gun to “freshen it up,” then it should stay in operating condition for the next time you need it.
That said, if you only need it once every few years, there’s probably no reason not to just buy a single-use bottle even if you don’t use all of it.