Tapered Mast Mounting

[Texastailboard]

Guy I have a tapered radar mast " seaview"with spreaders that we want to mount to our hard top. It came with a backing plate, my question is the backing plate enough to handle the weight and stress of the seas forces. How would you guys recommend mounting the mast to the hard top. The mast has place for our 48" open array along with the sat tv.

Thanks

Brooks

 

[Glory]

Some photos might help?

 

[Texastailboard]

It has a 10" mount plate with a backing plate of the same size. My worry is that my hardtop is cored and would not have the strength to mount it.

 

[jim rosenthal]

It has a 10" mount plate with a backing plate of the same size. My worry is that my hardtop is cored and would not have the strength to mount it.

What about removing the core over that area, or a little larger area, and replacing it with something sturdier? I think your concern is legit.

 

[bobk]

What about removing the core over that area, or a little larger area, and replacing it with something sturdier? I think your concern is legit.

Some thoughts:

1, Can the manufacturer of the hard top provide guidance.

2, custom fabricate larger backing plates.

3, Rout out the coring under around the mounting holes before drilling all the way through (from the top) and fill with thickened epoxy with glass whiskers.

Nice looking radar mount BTW. I'm envious.

Bobk

 

[Artzco]

In 2014, I upgraded my electronics and installed the Seaview mast. I was lucky to have a mount already in place that held the radar. I did have to drill new holes to match the mast base and then used large diameter heavy washers to securely bolt the mast. The original base was mounted to the hardtop and appears to have been strengthened with fiberglass and then mounted with about 10 large bolts.

Here is a couple of pictures of the finished install. I used Seaview's light box post to mount all 3 of my lights. The overall mount is quite strong.

 

[Texastailboard]

Artzco, I have a similar radar mounting bump on my hardtop. I noticed that you used that to mount the mast. Did the angles line up and so far has it seems to work well for you? We have the same mast set up and just want to clean things up on the hard top.

 

[Artzco]

Artzco, I have a similar radar mounting bump on my hardtop. I noticed that you used that to mount the mast. Did the angles line up and so far has it seems to work well for you? We have the same mast set up and just want to clean things up on the hard top.

The existing mount on mine was about 4" high with an access panel that allowed me to reach in and place the washers & nuts on the new bolts. Also, it let me run all the wiring up through the mast for the radar, TV dome, GPS & lights. Just be confident that your base mount is adequately bolted to the hardtop.

Everything has worked very well.

 

[oscarvan]

To add to some of the above....... 10" seems ok, larger probably better.

Obviously you will have to bolt through, but what you don't want is the bolts pulling the plates and fiberglass outer layers against the core. Too much flex, not enough strength, and a high probability of water intrusion.

A trick I've used many times is the following. (See illustrations in attached file)

Drill the hole for the bolts, all the way through.
Now chuck a nail, head removed and bent 90º in a drill and route inside the laminate, all four holes, creating a 1 to 1-1/2" diameter cavity between the holes in the laminate. It may be easier if you do this in two or three steps of increasing diameter. Also, have an assistant hold a vacuum cleaner up to the bottom hole to remove the waste.
Tape off the bottom hole and fill the cavity with epoxy.
After it cures re-drill the holes for the bolts.

Now you're pulling against solid glass, no flex and better load distribution.