Anyone try using 3m VHB tape to install a maxxair deluxe?

CamperDude · 10-21-2022, 09:11 PM

I'm replacing a rooftop AC with a vent fan. It annoys me the huge heavy rooftop ac could be mounted without holes while this 20lb maxxair needs a crazy ammount of holes. Wich brings me to the question..

Anyone try using 3m VHB tape to install a maxxair deluxe? Whats everyones thoughts on this? I have read of solar installs with it by taping the mounting brackets to the roof. Seems like a solar panel would catch allot more drag and have less surface contact with its brackets then the vent fan would have with the roof.

ScrapIron · 10-21-2022, 09:15 PM

A roof top AC uses a different type of mounting system and it weighs alot more than a vent fan. The reason the vent fan has so many screws is so that it doesnt leak water when it rains or snows.

boywonder · 10-22-2022, 02:30 PM

Try it......you can always undo it.

McMaster sells VHB in many different flavors........

SMB123 · 10-22-2022, 02:55 PM

Do you plan to seal it after? If I were doing a vent with VHB , I'd clean down to bare metal, tape, then seal off with self-leveling sealant. All that surface area should hold it down.

larrie · 10-22-2022, 08:37 PM

I attached some Unistrut to the top of my fiberglass Jeep roof with VHB tape. My traction boards get mounted to the Unistrut. The boards create a lot of wind drag. Have no problem with the VHB coming lose.

For you fan, I would suggest the VHB and then caulk around the outer edge to prevent water intrusion.

CamperDude · 10-23-2022, 09:06 AM

I plan to clean the area with rubbing alcohol, apply VHB tape to the fan mounting bracket, then mash it down on the roof as hard as I can. I'll then apply self leveling sealant over all the empty screw holes and outer edge.

My only concern is the roof has a slight curve in it from side-to-side. so the middle of the bracket, front and back, will have 100% surface contact. while the edges, left and right, may not.

My double sided tape is set to arrive today, and the vent fan is already in the roof wired and ready to go. All i have to do is tape and seal it when the tape comes in. I'll let you know how it goes.

CamperDude · 10-23-2022, 03:23 PM

Okay got the fan bracket installed. Looks like it's going to work very well.

I solved the issue of the slight curve in the roof by doubling the tape on the sides. It looks like all the tape is making contact with the roof. I filled in the grooves with layers of the double sided tape. I'll later fill in the grooves with sealant as well. This stuff sticks hard I'm not worried about it coming lose at all. More worried if I ever have to remove it!

I'll finish up with a sealant to weather protect everything and fill all the cracks tomorrow.

86Scotty · 10-23-2022, 06:06 PM

I'm curious to see how this works out. I've mounted lots of these things and there are a lot of screws through the roof. I hope it works for you, please report back.

BCam · 10-23-2022, 06:12 PM

I'd suggest using Eternabond tape to waterproof the top flange rather than a self-leveling sealant. It looks better and lasts a long time.

CamperDude · 10-24-2022, 11:32 AM

left it clamped all night. took the clamps off and gave the bracket a few tugs. feels solid.

Put self-leveling sealant all around and over empty screw holes.