Chafe protection for electric wire
 

Hi Brian,

I'm wondering what to use for chafe protection. Were going down to the boat next week, and I'll be mounting a radar and to GPS antennas to the mizzen. I want to run the wire inside. The radar is the largest of the cables, it requires a 1 inch hole to get that flat connector through. The GPS ones are much smaller. And each one has to have some sort of a strain relief at the top end.

On our smaller boat I was able to use a grommet for whatever I wanted to run up the mast. But this mast is going to be much thicker, and the grommets I have are made for relatively thin plate, probably 1/8 inch. I have some NEMA fittings, in the appropriate sizes, but they require either a nut behind them, or to be threaded. Threading would be difficult, since I would be leading them through a curved part of the mast. So I was thinking that there is something that you professionals use.

Best wishes, Tom

You can make your own "grommets" in place with silicone. After you have run the wires and cables, fill in the exit holes with several successive applications of electrical-grade silicone, keeping the wires roughly centered in the openings. (The number of applications depends on the size of the holes and the amount of empty space to fill.) This is effective for chafe protection but not for strain relief. This approach was suggested to me by a rigger several years ago when I rewired my mast and it has been effective.

Jim Fulton

Hi Jim,

Well, I hadn't thought of that. I did think of machining my own grommets out of some sort of rubber, but I didn't really know which kind would have sufficient UV protection. Or where to get the stuff when I did decide what I wanted. I'm still hoping for a magic bullet.

Thanks, Tom

Rounding and smoothing the edges of the hole in your mast would also help.

That way if whatever you use as chafe protection starts to fail, the chafe from a rounded surface will be much less than you would have got from a sharp corner.

Hello,

This is one occasion that using a professional rigger is in your best interest. I have done the DIYS approach on this in the past and been unpleasantly irritated about resulting issues that I was not aware of. There are two key issues of concern, 1 putting holes in your mast up to 1" in diameter is a big deal and if done incorrectly can potentially weaken the mast and cause a failure. 2. Electronics are quite spendy, you really do not want to do a substandard instillation that may cause them to fail in the future. You can get all kinds of advise on forums like this on what the best approach is, but the best approach really is to hire a professional rigger for a couple hours minimum to come down and advise you on how best to approach the task at hand. There are all kinds of variables that may not be taken into consideration when your only goal is to get something on mounted on the stick.

Jake

Mcmaster-Carr has large rubber grommets. I would think a combination of a grommet and a 2 part silicone would do the trick. Use the grommet to position things, and seal with the silicone. The silicone is more UV resistant than most rubber, and using the 2 part means you can build up the full thickness in one operation. Nothing sticks to cured silicone, including silicone, so "building up" multiple layers of air cure silicone can be problematic. Is there no way the connector can be removed/reattached so you can use a smaller hole?