Tape from the tube to the outside of the recessed area. Yes, it will look messy.
Alternatively, you can use a better tube and better clamps, then taping is not needed.
This is part of the GF design that should be changed in V2, IMHO. The tube should extend farther out the back, or the cutaway should be bigger to allow the clamp to fully seat. Aside from the over reliance on the lid camera, it is the biggest design flaw.
I can’t easily get to the back of the unit until late tomorrow. When I received my PRU unit in February they did not include the hose clamps. I had two 4" worm gear clamps that are commonly used for dryer vents. Those do not have the metal ears sticking out. Don’t over think it. Here is an idea of how ugly it can be on the wall. But works just fine.
Agree. I used small pieces and taped it as carefully as I could. It looks bad but nobody sees it.
@marmak3261 developed a 3D printable extension for the back.
They’re also made commercially. Supposed to be 4" ID on one end and 4" OD on the other. I got one and it was too oversized to make any kind of decent fit on the GF exhaust. I’ll look elsewhere (found that one on Amazon) and bring some hose to check it before buying to see if there’s an alternative for the 3D printerless crowd.
If you get this type of tape, it is more “conforming” to difficult angles than the standard acrylic adhesive foil tape, and it is also way stickier. I found that in my usage, regular foil would seem like it’s on perfectly tight but would eventually pop up just enough to let some smoke escape.
Thanks for digging out the link.
I’m still on my hunt for the commercial version.
Although come to think of it, I don’t know that I actually measured the ID of the adapter I bought. It might be that the OD of the flange on the back of the GF is smaller than the 4" that the hose is designed for and that’s why the adapter was too big (but it was the right size on the other end to take the 4" hose). I’ll measure it tonight to check.
I bought a commercial one, and it did not fit; it was way too loose. I can’t find the link to the one I bought at the moment.
Thank you. I don’t do 3D printing at the moment, but I am going to bookmark this for possible future use. And I am sure others here will get some use out of it.
Man, I should leverage this position a bit and help some folks out. Though 3D hubs gives a PLA quote of $16.00 for my flange, then there is shipping.
So I measured the commercial 4" ABS adapter and the ID of the large end is 3.95" and the OD of the small end is 4". (The OD of the large end is 4.125"). So looks like the GF exhaust flange on my PRU is not 4" but something fairly substantially smaller. Works with the clamp holding the hose on but might also be another part of the odor leakage.
Well, my improved exhaust hose and clamps are working great. I only smell anything at the end of the job when the fans cut off (come on GF, how frigging hard is it to update the code to leave the fans on longer?).
The problem was apparently leaks around the window vent - solved with some weatherstripping and copious amounts of foil tape.
Yay! It’s such a better experience when you’re not breathing the fumes 
Now, off you go to laser everything!
Thanks @jamesdhatch, @jbpa for suggesting and finding @marmak3261 flange - and many thanks for @marmak3261 for designing its awesomeness and giving away the STL!
I had a friend print me a copy
I think it really did help with the seal on the GF side a lot - great fit - tight, but not breaking anything.
I still don’t have my venting issue completely resolved, but I do seem to be getting closer
I use this to attach the hose to my GF. The rubber boot makes a tight seal on the short flange of the machine.
That looks like a nice one…I like the rubber fitting, that should seal really well.
I have a bunch of these in my garage and I never thought to try it. Time to go experiment.
Very awesome @ericlew44 !
If the 3d print from @marmak3261 design doesn’t do it for me I’ll try that next.
@jbpa I’d love to hear back on how it works for you (and ideally grab some pictures!).
I’m a lot closer to feeling like my venting is working, but still seems like I missing something (might be tape issues - I have @chris1 's recommend tape on order, at the moment I’m using gaff - and air-tightness isn’t exactly its intended use-case)
Here you go. It fits perfectly and seems much more secure than just having the duct on the GF. With this on, I have a higher quality duct that I want to try when I have a few minutes to spare.
Oh, that is very cool @jbpa !
Was it a fight to get the clamp up far enough on the elbow that it would cinch down on the GF ring? (The product picture almost makes it looks like there is a grove right at the edge for it)
