On my Lazy Daze I put a 1 1/4" roof penetration in to run various antenna cables and solar panel wiring thru. I made the penetration like a sewer vent, and kept the pipe plugged with high density foam. Never leaked, and gave me flexibility to change antennas (Ham radio) if I wanted. I would like to do the same on the FT, bringing the penetration down into the "entertainment" cabinet above the driver. Not familiar with the FT roof construction so not really sure.
Comments ?
I like the Blue Sea Systems Cable Clams.Cable Clams (https://www.bluesea.com/products/category/Cable_Clams)
Don
I used the Blue Sea penetration on the boat, but it is limited to single cables, my method allowed multiple cables, and flexibility, to add and subtract wires and cables.
The ones that are top entry are more flexible. They come with two different size bushings and one solid plug that you can drill to suit. Conceivably, the cable diameter could be a bundle up to nearly an inch. I have one of these covering the hole where the CB antenna penetration was for future use.
http://www.bluesea.com/products/1003100/CableClam_with_Stainless_Steel_Dress_Cap_1.40in. But perhaps you are already familiar with these and need more flexibility than they offer... Just an option where it fits the need. I was delighted to find these and using two of the side entry versions for the LTE antenna and a cat 6 cable let me clean up that original TV antenna mess. I was able to run the antenna alarm wire through with the LTE antenna cable, so depending on the diameter, it is possible to run two cables through one cside entry cable clam. I believe it is prudent to also use a dab of silicone (to seal but yet be able to remove easily later) where the cable enters the cable clam.
Don
We used this solar combiner box:
Roof C-Box | Combiner Box (http://www.amsolar.com/home/amr/page_72_16/roof_c-box.html)
Use an electronic metal detector or marking roof on a high humidity morning to locate metal roof supports. We siliconed the box down to the roof with some screws.
The box has a place where we cut a wide rectangular hole through the box & roof, which is used to run solar and many antenna cables into the coach. We drill holes on the sides of the combiner box to run terminated wires from roof into box and then into the open roof hole. These side holes are silicone sealed and the top of the box has a water proof cover. We do not close off the roof hole inside the box.
BTW we replaced the bus bars that came with the combiner with longer ground bars that have more connection points so each of our 6 solar panels have their own connection.
But I also think that a large enough round PVC pipe could be sealed through the roof and cables run into drilled & sealed side holes. And a slip or screwed on PVC cap could be used to seal the top and also have access to the inside of the pipe.
For my solar cables I took off the one from AMSOLAR and made mine using a 6x6x6 PVC electrical box and made the buss bars to suit as I run #2 cable down roof fridge vent access to Controller/breaker . The cables come into box via weatherproof fittings and then all is caulked. This box is a lot cheaper than the old one and a lot stronger.
Do not have a picture of it but can take some if needed.
JohnH
If you can't see where the aluminum square tubing is located in the roof, use a stud finder and mark each side. It worked very well for me. The roof has a thin glass layer and then wood bonded to it for a total of .400 inches. Foam is under that. I brought gray PVC electrical flex from the panels into a grey PVC electrical box with about a 1.5" hole down through the roof. Sealed with GE silicone II. I brought 72 volts with solar spec wires down to the behind the controller where I made a buss connection to feed the controller.
Pierce
Look around in the cabinets and you may find some cover plates where the horns are mounted. Pull them off and you can see how the roof is constructed. You could duplicate this for your mounting.
Keith