Installing a 4" precision port?

[eyekode]

Has anyone used one of these things?

I have installed a 2" precision port before. Very simple, the outer flare has both a flange for bolting/gluing and a nice collar to ease installation. In my case I cut just about a perfect circle matching the collar diameter and the collar provides a large gluing surface.

But the 4" version is another beast. There is no outer collar. Just the flare.
The outer flare is huge on this thing. It goes out to 7 1/4". I figure I will have to cut ~6.5" hole to mount it. And because there is no collar it will only be held on by screws and glue on the flange.

Anyone have tips for mounting one of these in a horizontal orientation?
Thanks!
Salem

[Mike P.]

There are 2 different size flared ends. The smaller one is the inside (the box) flare and the bigger one is the outside (the box) flare. The smaller flare is the template for your cut out. Test it on a piece of cardboard to verify. I used a bead of putty and screws to mount mine.

[eyekode]

Mike P. wrote:

There are 2 different size flared ends. The smaller one is the inside (the box) flare and the bigger one is the outside (the box) flare. The smaller flare is the template for your cut out. Test it on a piece of cardboard to verify. I used a bead of putty and screws to mount mine.

Thanks Mike. Did you also provide support for the flare within the cabinet? For example cutting a ~4" hole in a brace within the cabinet?

[Mike P.]

I've seen what you mentioned, personally I've used a "half circle" brace for the tube to rest on.

[eyekode]

I ended up using what you recommended. After test-fitting the port I measured how high I needed to make the brace. I left a little height so I could put a gasket under it. I then cut a small piece of scrap for the port to rest on. I cut the top of the scrap into a half circle. I used some closed cell foam tape to go between the brace and the port. Works like a charm. Not 100% sure I even needed the brace, but it seems like a good idea to take the pressure off the flange.

[Mike P.]

Good to hear it all worked out for you!