I'm replacing my Sensar antenna head because one of the aluminum wings broke off my old one. While I'm at it I'm going to replace the coax with new RG6 and replace the cumbersone cable bulkhead plate with a cable gland like this:
2 Pack of IP68 Waterproof Solar Cable Entry Gland by Restmo, Weather Resistant Dual Cable Entry Housing for Solar Panels of RV, Caravan, Marine, Boat, Cabin, White Amazon.com: 2 Pack of IP68 Waterproof Solar Cable Entry Gland by Restmo,... (https://a.co/d/jgOiglH)
I'm looking for some advice on how to fasten and seal this penetration. I'm considering butyl tape, VHB tape, and Dicor sealant or some combination of these materials. Would I also need screws or would the adhesive nature of these products suffice to keep the cable gland housing attached to the roof. Any advice is appreciated.
Hello George,
What kind of antenna will you be installing to replace the one that is broken?
The glands have a sealant channel. I would use 3M 4200. Clean fiberglass roof with isopropyl alcohol and wipe down the sealant channel as well. Apply sealant to channel and hold it with a couple pieces of blue masking tape while it dries overnight. Let it set up before running your wires. I probably would run a bead of 4200 around the perimeter for insurance. Pay attention to the temperature recommendations on the 3M data sheet. It also doesn't store well after opening so not a good idea to go big.
I second the suggestion of the 3M adhesive sealant, either 4200 or 5200. I have used both of those products on boats and motor homes for many years and they have never disappointed me.
I agree with using the 3M 4000 products. 5200 is to strong-- if it ever had to be removed, it would take roofing Fiberglass with it.
And, my fix is to buy a piece of aluminum from a box store that will more than cover the penetrations. Paint one side white to match the roof. Run a wide (or two narrow) beads of the polysulfide around the opening and fill the screw holes. Place the aluminum on it and a concrete block or other means of keeping it firmly in place until the polysulfide cures.
I'm staying with the Winegard Sensar IV because I like the fact that it is directional and it has worked very well for me. I'm not sure why mine broke. It was a newer replacement head for the original Sensar III. I heard it rattling on the roof during my trip to Colorado and then it stopped. Found out later that the forward wing snapped off. After that it didn't work at all. I also have the Sensar Pro digital signal strength meter which did factor into my decision to not switch to a King antenna.
From what I've read, that is still the best antenna for pulling in weak signals.
---
My thoughts on the cable gland, and just IMO.
Whatever you mount it down with should provide the primary water seal, any top cover lap sealant is just to shed water away but should not be used as your primary seal. Given that, I don't think VHB tape would be a good choice here since I think it would be difficult to get a continuous seal around that flange and you would be relying on just the lap sealant.
Screws or not, I'd prefer not, its just another penetration to seal. But use them if you need the hold down strength, like if you have large diameter cables that are causing the cover to lift.
You can hold it down / seal it with Sikaflex 252 or 3M 4200, those are flexible adhesives that have very good holding power and can be removed if needed. After it cures, use a lap sealant around the perimeter. There are stronger adhesives as well, like 3M 5200, but if you ever needed to get the cover off, it will be very difficult.
X2 on this, 3M are great products, but 5200 is for when you NEVER want it to come off, without the aid of a grinder.
Please don't ask me how I know that. :-X O:)