Bonjour Michel,
Your English is great - totally understandable.
However, I'm wondering if your
windows need new seals or operators. The reason I say that is that I never get any water inside my
jalousie windows if they are closed. And if they are open (which they usually are), no water accumulates. And we get some pretty intense downpours here, so it's not like I'm in the desert.
One time I drove through an amazing, flood-like downpour on the freeway. I was literally plowing through water it was coming down so hard and so fast (I pulled over as soon as I could, but had to drive a ways first). Even then, no water came in through the
jalousie windows, and there was no mopping up or manual draining needed.
I also don't believe the
windows have any drain holes, but I'll have to double check that.
So, I think I would try to see why water is getting in, and if it's missing or deteriorated seals perhaps you can fix them rather than modifying the window.
Raya