Installing a pole mount for radar

[Tenedos]

After a lot of consideration, and a failed attempt to install the radar on the mast (previous owner put silicon inside the mast at the deck level, which prevented running the cable without bringing the mast down), I decided to use a radar pole. I bought a Seaview RM8148 pole mount kit. I am planning to do the installation myself.

I am pretty good with electronics and reasonably handy with mechanical things, but never opened a hole on the deck before. Any recommendations or best practices? Pitfalls to be mindful of?

[RaymondR]

I tend to avoid holes in the deck wherever possible, they are hard to seal and sooner or later leak. I now try to locate penetrations on vertical or sloping surfaces.

I am upgrading my radar. The old one is mounted on the mast but the large cable rattles as the boat rolls and the radome interferes with the staysail. The upgrade is going on a pole mounted on the transom, the cables will penetrate the transom and be glanded, and I have put a hinge in the pole just above the solar panels so that I can mount the radome, and work on it in future by hinging it down to deck level.

[Tenedos]

I should have been clearer. It will be a transom mount but one there is an additional leg for strength, I think I will need to mount the base of that leg on a horizontal surface (deck?), I will try to avoid it though.

Also I opened the box today for inspection. This doesn't have a backing plate, I think I want one for additional strength. What would work the best? I read some people use G-10. Not sure where to find one. How about aluminum?

[chowdan]

Plate aluminum would work just fine. The forces it will see aren't huge and if it were me I'd probably use some flat bar stock around 1/8-1-4 inch thick.

If you to aluminum use 6061 grade as it is more corrosion resistant.

Online metals.com is a great source and has great pricing. I've used them for a fair amount.

Boltsdepot is also a great online source for fasteners if you need them as well.

Originally Posted by Tenedos

I should have been clearer. It will be a transom mount but one there is an additional leg for strength, I think I will need to mount the base of that leg on a horizontal surface (deck?), I will try to avoid it though.

Also I opened the box today for inspection. This doesn't have a backing plate, I think I want one for additional strength. What would work the best? I read some people use G-10. Not sure where to find one. How about aluminum?

[Tenedos]

Originally Posted by chowdan

Plate aluminum would work just fine. The forces it will see aren't huge and if it were me I'd probably use some flat bar stock around 1/8-1-4 inch thick.

Thanks chowdan. Found a polycarbonate sheet in Home Depot, I will try it as the backplate, seems robust.

Now comes the tricky part of drilling holes on the transom. I need 4 x 1/4 inch holes. I consider drilling the holes with a 5/16 bit, filling them with JB WaterWeld, letting them cure, re-drilling with a 1/4 bit and caulking with 3M 4000 UV. I am nervous of causing water leakage into the core. Any advice on this plan?

[cortezsailor]

I added a pole and was lucky enough to be able to cut through my combing on aft end and run the pole through my lazzerette where I Ubolted it to a bulkhead . No holes on my deck

[chowdan]

I'd be concerned if there was flex the polycarbonate could crack...though itd be very doubtful if thick enough.

I've never used water weld, but I have used many gallons of west systems. Your method is correct.

Over size your holes, fill, redrill and mount. If your hull is not cored, tou wont need to do that though.

Before you caulk the foot down, I'd recommend taping around the foot, as close to the foot as possible, then also taping up the foot. Once you goop up and bolt down, run your finger around the squeeze out then pull the tape after about 20mins to an hour and you'll have a professional looking job!

Originally Posted by Tenedos

Thanks chowdan. Found a polycarbonate sheet in Home Depot, I will try it as the backplate, seems robust.

Now comes the tricky part of drilling holes on the transom. I need 4 x 1/4 inch holes. I consider drilling the holes with a 5/16 bit, filling them with JB WaterWeld, letting them cure, re-drilling with a 1/4 bit and caulking with 3M 4000 UV. I am nervous of causing water leakage into the core. Any advice on this plan?