Hole in mast for access to the wiring and plug.

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nlneilson

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Sep 1, 2014
48
catalina 30 Oxnard CA
I want to cut an access hole near the bottom of the mast to get to the wiring plug and the wiring.

Has someone done this and has suggestions or info on this:
is one side better than the other
Is there enough clearance to use a jig saw or is a small rotary needed so as to NOT cut the wires. Any info would be appreciated.
'79 TR
 
hvbaker

hvbaker

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Oct 5, 2010
322
Catalina 30 mkII St. Augustine
I would rethink cutting a hole in the bottom of your mast. How many have you seen on other masts?
 
jssailem

jssailem

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Oct 22, 2014
21,098
CAL 35 Cruiser #21 moored EVERETT WA
No experience with hole cutting.

I removed my deck stepped mast this January. The electrical wires were all butt crimped together. The VHF and Radar cables were both solid runs from top of mast to inside radio and display. So not sure what purpose an access hole would serve.

Beware if you try to cut a hole that you keep it above the mast step. Mine sits on the deck and is about 6 inches tall inside the mast. We did however create 2 small notches on the bottom edges of the mast to allow any condensation inside the mast to get out from under the mast rim.
 
jssailem

jssailem

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Oct 22, 2014
21,098
CAL 35 Cruiser #21 moored EVERETT WA
HV Baker makes a good point.

Got to remember there is a lot of stress on the bottom of the mast. All the force of the sail is transferred down the mast to the keel. For deck step masts this happens with the aide of the compression post transferring the power from the deck step to the keel. The forces drive the boat sideways. The hull and keel push this force against the water and the boat quirts forward.

Weakening the mast will only serve to give you a very bad day.
 
Anonymous 121765

Anonymous 121765

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Jan 6, 2010
1,520
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NL,

I'll probably take some hits for saying this but, I added opposing 3" vents in my mast.
Along the bottom edge, I used a 1/4" drill bit & hogged out notches to allow any sitting water to drain out.
I had the mast stepped & repaired the deck sag. There was little or no seal for the wire penetrations & the mast step bolts. This along with an open mast top crane (when it rained led to soaking my plywood coring.

Most of the mast's structural strength comes from the rounded front & rear shape & not the flat sides. To lessen rainwater coming in from the top I added a cover plate. There are still openings up top for venting. Now with the two vents, I have a cooling tower effect. Because of different air pressure across the mast top, air is sucked thru the vents & out the top along with moisture from any standing water at the base.

Here are some pics:

CR
 
A

alexco38

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Sep 25, 2008
1,096
CS 30 Toronto
Mine came from the factory with a slot on the flat side near the bottom for the cables to come out. Although it's a keel step mast, the principle is the same. No ill effect for 31 years.
 
seadaddler

seadaddler

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Dec 19, 2006
5,809
Hunter 36 Punta Gorda
Selden has a notch on the very bottom of mast for wires to pass out
the bottom of mast on both side very near the front of the mast before it starts to curve.
Nick
 
centerline

centerline

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Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
captnron said:
Most of the mast's structural strength comes from the rounded front & rear shape & not the flat sides. To lessen rainwater coming in from the top I added a cover plate. There are still openings up top for venting. Now with the two vents, I have a cooling tower effect. Because of different air pressure across the mast top, air is sucked thru the vents & out the top along with moisture from any standing water at the base.

CR
Click to expand
this is correct. some masts come from the factory with holes in them for access. these are usually fitted with a cover...there are others have been modified by a rigger or boat owner.... a narrow tall cutout is much better than a broad short cutout.... smaller in both dimensions are better.

I am NOT recommending that you do it, but if you are determined to go forth at your own risk, take a 1" to 1.5" hole saw and drill two holes, one low, staying at least 2"up from the bottom of the mast, and another one above it the distance you want the finished cutout to be...... after both holes are cut, use a saber/jig saw to cut out the web between the holes... with a bit of a steady hand, it will look like a professional did it....
stay away from the curved part of the mast and only cut out the flat, and as little material as you need to get the job done, and NO SQUARE HOLES.... corners are where the stress will run to and start cracking the material that you dont want cracked.
 
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dj2210

dj2210

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Feb 4, 2012
337
Catalina 30 Watts Bar
I added an access hole. Used a hole saw and then machined a cover plate and four 1/4 -20 flat head screws tapped into mast. I can get my hand just through the hole. Easy to pull out wiring and plug. Second picture you can see the cover plate at the bottom of the mast
IMG_1255.JPG
IMG_1721.JPG
 
Anonymous 121765

Anonymous 121765

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Jan 6, 2010
1,520
DJ,

Hey pal, if you can & may also have an open mast top, I got my vents @ Waste Marine.
I would not be surprised if you can find a match for your close-off plate.

CR
 
OS2Dude

OS2Dude

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May 7, 2011
206
Catalina 30 Lake Lanier
You can remove the bottom sheaves and gain access that way. I would not cut another hole (especially a large hole) in a mast.
 
N

nlneilson

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Sep 1, 2014
48
catalina 30 Oxnard CA
Thanks for the replies, pictures and especially the advice.

I have had someone climb the mast 4 times. At 72 and about 240 lbs I would rather not try it myself/ even cleaning the bottom is more of a challenge than it was 35 years ago.
I want to get to the plug for the wiring. To get to the wiring under the mast from the cabin could be a challenge. Every vehicle I have owned I could work on almost every item, even an airplane as I have an FAA A & E (Airframe and Powerplant) mechanic license.

Two holes with a hole saw and then the vertical edges with a jig saw.
A cap or some type of cover over the top of the mast is a good idea also.
An led anchor light, an additional GPS receiver and an emergency strobe light will go on top.

Neil
 
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dj2210

dj2210

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Feb 4, 2012
337
Catalina 30 Watts Bar
CR- I thought about a vent but since I have the exit blocks right below the opening I cut I decided to just make the blank. The blank is machined so it fits on and into the hole for strength. Oh and the exit blocks make it nice for wasps to enter to get out of the rain...
 
jssailem

jssailem

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Oct 22, 2014
21,098
CAL 35 Cruiser #21 moored EVERETT WA
Neil.
I see you are considering placing a GPS antenna on the mast head. This may not yield much in the way of improvement. Think about the purpose of GPS. Your trying to find your location. On the cabin deck as the boat moves it is close to the earth surface. The angle to the satellite would show less physical change due to height. Location is within a circle based on the height above the surface. Locate the antenna some 40 or more feet above the surface now you have a bigger circle that you are somewhere within. The circle is created by the bottom of the mast close to the surface and the antenna waving about 40 plus feet in the air. Attach this to a display of your location and you will paint not a line of progress to your destination but something more like that of a sailor who has enjoyed too much rum.

Suggestion. Locate on the deck or a pulpit where it can receive a mostly clear look at the sky.
 
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