Attaching Accessories to Aluminum Mast

[The Blue Heeler]

Guys, I'm headed up to Sandusky to work on my new E29 this weekend and am going to relocate my VHF antenna from the stern rail to the mast. What is the best fastener to attach an accessory like this to an Aluminum mast. Obviously you can't get to the inside of the mast to put nuts on the back of bolts. Do you use Rivets? If so, what kind? Also, what should I use to seal the hole where my coax exits the mast if any?

 

[HGSail]

MY bracket is mounted with stainless screws and bedded with Dolphinite. I havn't had any problems with this method. As far as closing any holes, If you can have them HeliArced closed. If there is an exsisting coax in the mast from a previous antenna I would use the old hole for the new cable.

Pat
E29
'73
#224
Holy Guacamole

 

[Loren Beach]

"Can you hear me Now?"

Bart,
Like your avitar!!
(Personally I gravitate more toward Dr. Zoidberg...)

Unless your stern rail antenna is brand new, I would also put a new one at the masthead. It's a very long ways up there to replace it, again.

We have that masthead L bracket screwed in with machine-thread SS screws. Gooey up the tapped holes with sealant and also seal the interface between the SS bracket and the spar with sealant. This works for my installs for a decade at at time, but then we are primarily in fresh water.

Further, if you have a working stern rail antenna, why not keep it and put a splitter for the new coax run to the masthead? In the unlikely event that the mast falls down, you just switch over to the other antenna and keep on talking...

Best,
Loren

 

[The Blue Heeler]

Thanks

Yes, I just found the Avatars and thought it fitting for my name. Anyway, so you recommend that I drill pilot holes smaller than the stainless screws and then use the stainless screws to attach the antenna? Can I get the dolphinite at West marine? I will take your advise to keep the wiring near the stern rail for emergency use and will get a new 3db antenna to go on the mast. Right now the mast is down so it's a good time to mount the antenna and rewire the mast completely. I'm also going to mount a new headlight/decklight on the mast and the holes may not mount up so I was going to use the same mounting method for the light.

I'm very excited because we bought the boat in November and I've not even seen it since then. It's an 8 hour drive to Sandusky from Nashville.

Any other tips would be appreciated.

Thanks!
Bart

 

[NateHanson]

If you use machine screws you'll want to drill and tap the hole before screwing in the machine screw.

Sometimes at the masthead (depending on what your masthead looks like) you can get inside the mast to hold a nut on the back of a machine screw. That's ideal, IMO, because then dissimilar metal corrosion won't loosen the connection between a stainless screw and aluminum mast.

When tapping a machine screw into the aluminum I use loc-tite thread locking sealant. It will keep the fitting from loosening, and it isolates the metals to prevent corrosion. Also, cut a piece of milk jug or shrink-wrap plastic to serve as an insulating gasket between the the mast and the object you're mounting, if the object is metal.

Nate

 

[Frank Langer]

Just one more tip--it's a good idea to let the wire hang down a bit below the entry hole into the mast, so that rainwater dripping down the wire falls from the bottom of the wire, rather than sliding down the wire directly into the mast. I can't do a picture, but maybe someone can add one to show how the wire should be looped a bit to achieve this. Also a rubber grommet will help to avoid chafing of the electrical wire entering the mast.
You might want to consider replacing all light bulbs while the mast is down, to avoid a trip up the mast in the future for a burned out bulb.
Good luck.
Frank.

 

[Erich]

Another use for your present stern rail antenna is to use it as the FM antenna for your stereo. Not being sure why the PO had "added the stern rail antenna for his VHF" when he did have a masthead mounted one, I decided to clean up the stern rail. I was doing this while listening to the radio. As soon as I disconnected the antenna, the reception was notably worse. I reconnected it for the FM. I suspect that there may be differences between the optimal VHF vs FM antenna but mine seems to work well for the FM. I can always use it as a spare for the VHF.

Cheers,
Erich

 

[EGregerson]

hole

Lowe's has a (very reasonably priced) package with drill bit and appropriately sized tap (so u don;t have to buy a whole set) Also recommend a center punch.

 

[The Blue Heeler]

Good Tips

Thanks guys. I've now added tap and die set and centerpunch to the list of tools to take. As to the PO, there was never a mast mounted antenna. The PO just mounted the antenna on the stern rail for convenience. I like the idea of the higher mounted antenna for better performance of the radio. He was on Lake Erie, I'll be in a lake that winds around a good bit, so I'll need the height.

 

[Mark F]

Hi Bart,
Here is a photo of how my antenna is mounted. I believe it is pop riveted on (maybe Monel [sp?] rivets). You can see how the cable is routed so the rain water drips as per Franks suggestion.

 

[JORGE]

Mast wiring- Blue heeler

For the Blue Heeler)))
I am going to start re wiring my mast on E32, did you find out if your mast had a track for the wiring conductor to pass through. How were the wires supported.?

 

[The Blue Heeler]

What I found was a huge mess. There is no way that any electricity has passed up that mast in many years. After 4 hours, we finally got all the old broken, taped, ratty wires out of the 1/2" conduit that was in the mast. There was barely enough room to run the 4 wires that I ran up the mast. I decided to use a common ground and a separate hotwire for each of the anchor, mast head light and down facing foredeck lights. That gave me a total of 4. We tapped the mast and mounted the new combo masthealight/foredecklight with stainless machine screws and also the new 360 degree anchor light that we bought at West Marine while we were up there. Never even had time to try and run coax for a new vhf antenna. I may try to run that when the boat gets here. I still need to get the depth and knot through hulls installed before I drop her in the water so I might as well get the Vhf antenna issue fixed at the same time. HOwever, I will be chomping at the bit to get her in the water!!!!

I did mount a waterproof trailer hitch wiring connector on the new wires in the mast and on the wires coming out of the boat. Problem is, now I have to figure out where the ones going into the boat go to!!!

I think I'll pick up one of the wiring tracer units at home depot to help with this.

 

[JORGE]

E32 mast wire?

thanks ...Sounds like you had a conduit in the mast for running wiring.
I think that my E32(1971) has a built in conduit, I'll need to find out if I can run round or flat 14/3 & 14/2, or just one 14/4 as I think is recommended. I'd like to know if anyone with a E32 knows about the channel. In addition, I am thinking of using a high standpipe to run the wires under the mast to inside and then to the panel, instead of using an outside 4prong connector.(The terminal block is suppose to be inside the headliner above the compression post)

I found ((genuinedealz.com or bestboatwire have marine wire.).

 

[windjunkee]

We replaced the radio, antenna and coax last fall. (sorry, no photos). The job, which seemed pretty straightforward, turned into a nightmare with at least 5 hours logged at the top of the mast.
The mast doesn't have conduit running through it. It has foam plugs in at least two places. Replacing the antenna was the easy part. The bracket was already there and I simply disconnected the coax from the old antenna, unscrewed it from the bracket and screwed the old one in. For the coax, I cut the old one and stripped some of the cover off. Then, with the new one, from the top of the mast I twisted the wires and sheathing together and bound the joint with some tape. Then, my partner tried pulling the new one through the mast using the old one as a messenger. The problem came when the joint got caught up in the mast and parted ways. Now, we no longer had the old one in the mast and the new one was only a third of the way down.
We had to go buy a long fish wire. Then, from the top of the mast, we ran the fish wire down (this wasn't easy). We got the fish wire out from an access hole at the base of the mast and lashed a line to it using whipping twine. The line was then pulled back up the mast. Once it reached the top of the mast, I attached the new coax to the line, again using whipping twine for a very strong joint, and pulled the new coax back down. This worked, finally. I then liberally applied silicone gel to the connection and connected the coax to the antenna. It works fantastic, but the insides of my thighs were bruised for weeks because of all the time spent at the top of the mast holding on!
If I had to do it again, I would MAKE SURE, the joint between your old coax and new coax is strong. Twisting the wires together and taping them simply wasn't enough for the strain of having to pull the cable and that joint through the tight spots of the mast.

Jim McCone
Voice of Reason E-32 Hull #134
Redondo Beach, CA

 

[Second Star]

Attaching things to the aluminum mast or boom

I have used SS screws as well as pop rivets. The screws really don't have much depth of material to bite into and pop rivets need to be drilled out to release the object being attached. I am "experimenting" currently with "nut-certs" which are very like a pop rivet but allow a bolt to be used to do the actual fastening of the object. they came from the aircraft industry and are available in many tools shops etc.

 

[bgary]

Couple of thoughts to add to the above....

1) I used stainless machine-screws, coated with "tefgel" to minimize the marriage between aluminum and SS. Use *real* SS fasteners, not the zinc-coated stuff from Home Depot.

2) I sealed the point where the coax enters the mast by liberally wrapping the coax with self-amalgamating tape (to protect the cover), then gooping silicone sealant to seal the hole.

3) note that whether or not you can create a drip-loop at the top depends on what kind of coax you choose. I used LMR-240 "ultra flex", which has a minimum bend-radius of about an inch. Which means a drip loop has to be at least 2" in diameter. I ended up choosing *not* to do a drip-loop at the top, but put in a good strain-relief so the antenna connector doesn't have to carry the weight of the length of coax in the mast.

Bruce