mast conduit

[bletso]

OK, now I have a problem. I need to rewire the mast but one of the mast conduit retainers is bust. It appears the OEM welded in a series of U's to keep the conduit against the mast. I want to put all my wiring including the VHF in the same conduit which means I will have to up size the conduit. How do I accomplish this? I really don't want to go the welding route. Any idea's? I could make some special fasteners like the attached drawing if I can't find them. I am not sure a series of rivets would hold the conduit in place. The mast is 58 ft long.

[tkeithlu]

Can you get a stainless steel u-bolt around the conduit and then out the side of the mast? If so, I'd go looking on McMaster-Carr or similar and then use the appropriate size PVC electrical conduit.

[bletso]

A stainless U bolt would work once I figured where to drill the holes. It is trying to not put a big nut on the outside of the mast. I could use a slotted cap head cap nut if in SS.

[Jim Cate]

Pop rivets have successfully held conduits in place on my various boats for over thirty five years. if you use fairly large diameter rivets and space them a meter or so apart the support is pretty good.

Jim

[bletso]

That is certainly an easier solution. Thanks

[GordMay]

Originally Posted by Jim Cate

Pop rivets have successfully held conduits in place on my various boats for over thirty five years. if you use fairly large diameter rivets and space them a meter or so apart the support is pretty good.
Jim

Indeed.
See ➥ http://www.cruisersforum.com/forums/...ast-61324.html

[bletso]

Well thanks to Jim Cate, I went the rivet route. The problem was to get the conduit to stay put whilst drilling it. I predrilled the holes in the mast and then made a special jig to do that. It took about four modifications to the original design, but in the end it did what it was intended to do. It took 11# (5kg) to do the job.

[Jim Cate]

Glad that it worked out for you, and congratulations on the invention of the fixture to accomplish the job.

Jim

[Captsteve53]

Yep, you better put a patent on that,

But there is an easier way most riggers use as: Place the conduit inside the mast. Pop rivet the lower end of the conduit to the mast, you should be able to hold the conduit against the inside mast surface at the base to get this first rivet in. Form a stiff piece of wire into a hook. Push the hook through the next rivet hole and turn it so it grasps the conduit. Pull the conduit tight against the mast while you pop rivet through the next hole along. Move the hook to the next hole, pop rivet through the adjacent hole, and so on up the mast. I'm sure you get the idea. Others use the same technique but drill two holes close together (2") use the wire hook told hold while you rivet the other,

Also have seen holes drilled opposite the tube(tube laying in the bottom of the mast section) then spray expanding foam around the tube , actually glues pretty well (sticky stuff!)can't vouch for the longevity.


Cheers Steve

[UNCIVILIZED]

Originally Posted by bletso

Well thanks to Jim Cate, I went the rivet route. The problem was to get the conduit to stay put whilst drilling it. I predrilled the holes in the mast and then made a special jig to do that. It took about four modifications to the original design, but in the end it did what it was intended to do. It took 11# (5kg) to do the job.

Cool idea!

[GILow]

Originally Posted by bletso

Well thanks to Jim Cate, I went the rivet route. The problem was to get the conduit to stay put whilst drilling it. I predrilled the holes in the mast and then made a special jig to do that. It took about four modifications to the original design, but in the end it did what it was intended to do. It took 11# (5kg) to do the job.

Very nice gadget.

Now you have the same dilemma I face with the jig I made to attach the rub-rail to the boat using blind screws. That is, what to do with the jig? Keep it, just in case? Store it where?

[bletso]

Originally Posted by Captsteve53

Yep, you better put a patent on that,

But there is an easier way most riggers use as: Place the conduit inside the mast. Pop rivet the lower end of the conduit to the mast, you should be able to hold the conduit against the inside mast surface at the base to get this first rivet in. Form a stiff piece of wire into a hook. Push the hook through the next rivet hole and turn it so it grasps the conduit. Pull the conduit tight against the mast while you pop rivet through the next hole along. Move the hook to the next hole, pop rivet through the adjacent hole, and so on up the mast. I'm sure you get the idea. Others use the same technique but drill two holes close together (2") use the wire hook told hold while you rivet the other,

Cheers Steve

I actually tried that. It didn't work. I had pre-drilled the mast every 1.2M with two holes 25mm apart with the intention of hooking one hole, rivet, then the next. My mast isn't oval enough and the conduit had a mind of its own.

[bletso]

Originally Posted by GILow

Very nice gadget.

Now you have the same dilemma I face with the jig I made to attach the rub-rail to the boat using blind screws. That is, what to do with the jig? Keep it, just in case? Store it where?

No problem, I don't plan on using it again so it will never go aboard. I have had to make 4 different "special" tools/jigs. The first two will stay aboard, the last two were for one time use. Special Jigs / Tools | Sailing Vessel Vigah

[Roy M]

Here's how I do it:

1. drill holes in a straight line up the mast where the conduit will go.
2. drill a companion hole adjacent to the first line, just a bit more than half the external diameter of the conduit.
3. bend a coathanger or welding rod in a hook larger than the conduit exterior.
4. slide the conduit into position, insert the hook in the companion hole and confirm the hole for the poprivet will position the conduit perfectly.
5. drill the hole into the conduit, and while holding the hook securely, insert and expand the poprivet into the conduit.
6. repeat up to the last conduit hole.
7. fill the companion holes with poprivets.
8. never use aluminum poprivets, and if you can get them, pay for the better monel poprivets.

[chouliha]

Originally Posted by Jim Cate

Pop rivets have successfully held conduits in place on my various boats for over thirty five years. if you use fairly large diameter rivets and space them a meter or so apart the support is pretty good.

Jim

Jim that is what we have done for the past 30 years on Jacaranda and it's worked just fine.

We started with light pvc pipe joined with a wrap of duct tape to join them together.

Slide the pvc pipes into the mast.

Drill one hole in the mast (right next to where the pvc pipe will reside) to be able to insert a stiff wire hook to hook the pvc pipe and pull it tight to the mast and hold it.

Drill another hole thru the mast and thru the pvc pipe. Insert a pop rivet thru the hole in the mast and pvc pipe.

Once snapped off then remove the hook and put a pop rivet in that hole.

Move along 6 feet and do it again.

So far it's been problem free

Good luck

Chuck
Jacaranda

Roy - was typing this out and didn't see your post sorry for the duplicate explanation