Mast hole? Cut or not to cut?

Bob L · Post by **Bob L** » Sat Jul 15, 2006 10:11 am

I'm stepping my mast soon, and need to make a mod. How big a deal is a hole in the mast?

Here is the arrangement: Deck stepped, beefy stainless support post in cabin, wires run up the center of the post from it's base. On deck, a metal mast step, with the wires coming out the center. Nice and weatherproof.

At one point the mast on my boat was replaced with a used mast from a C&C or similar. The used mast was too long, and it was cut down to size. Fits perfectly, no problem.

However, there is no inspection plate, or access hole - if there was an inspection/access plate, it was cut off.

To connect or disconnect the wiring, the mast must "hover" over the deck! I have to place my hand between the hovering 400 lb dagger and the mast step to connect the wires. Not a good feeling.

Two alternatives:
1) Cut fist-size hole in the mast, about 12 inches above the step to access the wiring, and cover it with a plate. (Q's: How high above the step? What size? Round the corners?)
2) Cut a small hole (1" circle) in the mast, and run the wires outside through a hose and thru-hull fitting like on Glissando.

Pros and Cons: Hole in mast weakens mast, but snag-free deck, watertight, and cabin wires concealed in stainless step support. Small hole and tube, stronger, trip and snag hazard, exposed interior cabing wiring, deck penetration.

Thoughts?

Thanks!
Bob

Post by **Tim** » Sat Jul 15, 2006 5:38 pm

I'd go with the external wiring run and the smaller hole. Another option to build one of these arrangements is to use stock rail fittings at the mast and deck and secure a hose or whatever to those. I find that this basic system works extremely well, and can't see a reason to go any other way. The ease of access makes whatever cabin modifications to hide the wiring worth it, I think, but each situation is different.

For the reasons you stated, I think that wiring straight through the mast base on a deck-stepped mast is ridiculous. I'd change that in a heartbeat.

Small holes in the mast are no problem, but I'd hesitate a little to make a hole that I could fit my arm through!

Bob L · Post by **Bob L** » Sat Jul 15, 2006 6:36 pm

Right, "no way" on the fist sized hole...

I'm a little hesitant to do the fitting&hose - I'm going to strip the teak off the deck this winter and would like to leave it intact for now. Perhaps I can make a hole in the mast the same size as the OD of the hose I will use, and I can fish the wires out when I need to... idea coming...

oooh, oooh.... I can put a hole in the stainless compression post inside the cabin and use a piece of stainless rail up to the deck fitting. Wires enter at the base of the compression post as they do now, travel upward, exit through stainless tube and travel through the deck, into hose, and then into mast. Any water traveling down the wires would still be directed into the bilge. Plus, I could hang my foulies on it.

Standby.... processing... processing....

Thanks Tim :)

CharlieJ · Post by **CharlieJ** » Sat Jul 15, 2006 9:26 pm

In Don Street's Ocean Sailing Yacht, Vol II page 119, 120 he gives explicit directions, with drawings, of adding hand holes to the side of aluminum masts. If done correctly there should be absolutely no problems with a hand sized opening. It's done quite often on larger boat.

Figment · Post by **Figment** » Sat Jul 15, 2006 10:06 pm

"on a larger boat", the hand-sized hole is a smaller component of the total mast section. What size mast are we talking about here?

Even at the very base of the mast, where loads are almost always simple compression loads, I'd be reluctant to remove more than 10% of the circumference. But that's just my instinct.

This could be a good question for Spar Talk!!!!

Bob L · Post by **Bob L** » Sat Jul 15, 2006 10:19 pm

It's a fairly big section, I'm guessing 10" fore to aft and 4-5" side to side. Total length is 45'. I need to fish out the wires more that get my whole arm in there.

Bob L · Post by **Bob L** » Sat Jul 15, 2006 10:24 pm

CharlieJ, thanks for the Don Street reference. Since I don't have the book, I tried to find it on amazon in the "search inside the book", but it was unavailable. Rats.

CharlieJ · Post by **CharlieJ** » Sun Jul 16, 2006 11:25 am

Bob- I can scan those pages for you if you'd like

dkall · Post by **dkall** » Mon Jul 17, 2006 9:37 am

A friend of mine has a 43 Westsail that has the access plate and the boat has circumnavigated once w/o any problem. He thinks that is one of the best things about his mast setup.

Post by **Tim** » Mon Jul 17, 2006 12:18 pm

I have to say, I'm very interested to discover that I have never seen one of these masts with an access opening cut into the base for wiring like we're talking about here. I thought I'd seen a lot of boats, but there's always something new to learn!

I guess I must be used to boats with smaller spars that wouldn't accept such a large opening successfully. Normally, all I ever see is a 1-2" hole just big enough to bring the wires through.

BobL, if you can cut a hole large enough for your needs and be sure that it's safe (i.e. according to something like Don Street's info, or equivalent), then that is probably a good way to go for your situation, and will make it easier to keep the wires hidden inside.

Figment · Post by **Figment** » Mon Jul 17, 2006 12:57 pm

Bob L wrote: To connect or disconnect the wiring, the mast must "hover" over the deck! I have to place my hand between the hovering 400 lb dagger and the mast step to connect the wires. Not a good feeling.

The hand-hole in the side of the mast doesn't fix this situation though, does it? You'd still need to feed the wires in from the bottom before making the connections through the hand-hole, right?

(I don't think the hovering mast thing is a big deal really. Just trying to focus on the goal)

CharlieJ · Post by **CharlieJ** » Mon Jul 17, 2006 7:53 pm

LOL- yeah well- there IS that- You DO still need to reach under- but for a much shorter time.

Oh well- compromises, compromises- boats are built on compromises

Grin

Bob L · Post by **Bob L** » Mon Jul 17, 2006 9:06 pm

I don't need to get my whole hand in there, just being able to fish them out would be good. I got the Don Street book today, and he is generally against the idea though. I'll post a picture when I figure it out....

Ceasar Choppy · Post by **Ceasar Choppy** » Tue Jul 18, 2006 9:02 am

I recall Rig-Rite sold a kit a few years ago like the one you described for putting a hole in your mast with an access plate. I don't want to start a well deserved rant about Rig-Rite, but it is certainly do-able as long as you aren't cutting too much of your mast away.

The primary considerations are certainly the size of the hole, thickness of your mast and you need to make sure you round the corners-- the rounder the better.

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