NEED HELP keeping my Y-ducting on my vortex fan

Ok so i have my vortex fan with a y shape duct hanging on it. I cannot keep it on for the life of me. I used a clamp and tightened it as much as i can it it just falls off like its not even there. Then I duck taped the shit out of it and has been fine for a few days but i noticed it getting looser. Now today it fell off again. How the fuck does everyone keep it on. im getting annoyed.

Hey budsmoker... My y goes over the lip on the fan... does yours? I just used 3 self tapping screws screwed through the tin y into th flange on the fan and then aluminum taped it...

I've taped up some of my grow cabinet and the tape just goes loose when it heats up. The glue never sets properly so any heat and it comes loose. maybe silicone? or as the guy above suggested, screws!

I also use Self-tapping sheet metal screws to hold the 90's onto my air cooled hood as well as onto my 6" Vortex. It only take 1-2 screws with some that alumimum duct tape to seal for leaks and she's good to go.

or rivets?-

After sitting around and thinking about it for a second there was another option. You could place a short piece of rigid or flexible duct between the fan and the Y not sure on your exact space requirements but it would cut down on the pressure if the fan was blowing right against the Y or if your pulling through the Y it will reduce noise as the force will not be as great on the Y itself.

Muffy- Rivets would work also but most people don't own a rivet gun on the other hand most own some sort of hand drill.