Rain water through the mast

[jonelli]

I know I have leaks through the mast wires. I’m in SoCal so it’s not very often it happens. I remember seeing some posts about sealing the wires and even putting a cap on top of the mast. If someone could point me to the info that already exists so I could research this, I would appreciate it. If a mast cap could be done easily by climbing it, I would likely attempt that first. If that isn’t something easily done I would consider looking into pulling the mast the next time I haul it out and try sealing the wires. I don’t know what I’m getting myself into for that task though. I don’t know if the wires have to all be cut and respliced to do it, etc. thanks for any input.

 

[shemandr]

There is currently a thread "mast leaking through deck along compression post into cabin."
It is covering some of your questions.

 

[JoeWhite]

My understanding is that rain water rises in running rigging due to capillary action then drips down inside the mast and end up in the bilge. I do not have a solution for this. The holes on the top of the mast can be blocked by applying caulking.

 

[jssailem]

Yes water will find a way inside you mast.
It can generate from several sources.

• Moisture condensation due to temperature and humidity
• rain
• hosing down the mast and rigging
• splash during sailing

What ever the source dealing with it is universal.

• Seal the deck surface
• Clean or create weep holes to let water empty out of mast onto the deck
• Create drip looks on wires in the mast
• Caulk fasteners and holes for wires from mast to cabin
• Caulk/seal all fixtures around mast on deck

Here is an example of my deck step. The tubes create a thru hull for wires. The act as a snorkel to keep the opening for wires above and water in the mast. All were caulked with sealant. Weep holes were drilled in the bottom of the mast to allow water to escape.

The wires on the mast are fitted into pieces of hose to enhance the drop loops and eliminate the flow of water down the lines.


If you have a keel stepped mast, then a mast boot is used to seal the outside of the mast at the deck. Water coming down the outside of the mast is shed onto the deck.

Water will still find it’s way into the mast, running down the inside of the mast. The base step on the keel needs to be solid and impervious to water. The water will flow away from the mast base and accumulate in the bilge where it can be pumped over board.

 

[jonelli]

It’s a Catalina 30 with a deck stepped mast and a rigging plate. I think I’m going to first shove my endoscope camera down one of the halyard holes and try to see what it looks like in there.
I don’t have any other apparent leaks anywhere. Just that one when it rains.

 

[JoeWhite]

On my c36, water was leaking into the bilge from leaky windlass shaft seals aswell.

 

[jonelli]

Went to my boat today and discovered that I have two little access panels on either side of the mast. Looked inside for the first time and I can see the conduit stub. Also about an inch of bird crapping. I used white window caulking to fill the conduit hole and surround the wires at the pipe. I’m thinking of drilling a 1/4” weep hole at the bottom of the mast on each side at the mast plate. Any reason I shouldn’t do that?? Currently it looks like if the mast filled up to access holes it would be above the conduit pipe. I feel like a weep hole on each side of the mast would really minimize the water in there that could collect.

 

[jssailem]

That is what I have in my mast. The hole is near the base of the mast, and above the mast step.

 

[jonelli]

I was reading somewhere in another old post about how it is "supposed" to work by original design:
The mast is not sealed at the deck plate, so some reasonable amount of water should seep out and never rise above the wire conduit. Well, in reality, dirt, bird shit, and other stuff over years of time tend to make a pretty good seal around that area, and there's no way to clean it out without stepping the mast. I believe that's why they now make deck plates with larger weep channels in them, like the CD one they sell now.

Unless someone tells me otherwise not to, I plan on drilling a small 1/4" hole on either side of the mast then right AT the deck plate seam. Then, I'll clean out as much dirt and shit I can get out of there, and make sure the weep holes stay clear.

Seems like a stupid design knowing that the top of the mast is wide open for all kinds of garbage to get in there and expect it not to eventually be an issue. But I guess if you're making boats with the expectation that they are 10 year boats, then it seems fine?

My theory on my personal situation is that it has never been a severe issue (I've had the boat for 9 years now) but this past year we've had some serious bird issues and recently more rain than we've ever had. The bird poop was about 1" thick. I smooshed it around to be able to see underneath and could see that only the conduit stub was the only apparent open point to the interior.

 

[dmax]

"Seems like a stupid design knowing that the top of the mast is wide open for all kinds of garbage to get in there "

The top of my mast has a removable cover (Isomat) - I would look into fashioning something to keep the crap out, can't be good for anything that's in there. Does seem like a bad design.

 

[OS2Dude]

Went to my boat today and discovered that I have two little access panels on either side of the mast. Looked inside for the first time and I can see the conduit stub. .... I’m thinking of drilling a 1/4” weep hole at the bottom of the mast on each side at the mast plate. Any reason I shouldn’t do that?

The 'access panels' were likely originally for exit blocks for internal halyards. (Double Exit Block C-27, C-30 (catalinadirect.com) ) I would guess someone put in exit plates (Halyard Exit Plate Riveted, Plastic C-34, C-36, C-42 (catalinadirect.com) ), or worse converted it to external halyards. The covers should be fastened by bolts, not screws.

No reason not to drill weep holes, but the base plate is about 0.375" thick, so they will have to be off the deck about 0.5". (Mast Step C-30 Flat Base (catalinadirect.com) ) My guess is the notches on the sides of the step are to let water out since the mast sits on the base plate. I don't know if OEM plates had these, but since the joint of the mast to plate is not sealed water should find its way out in any case in all but a real downpour.

In my experience, most of the water coming into our bilge was from rainwater running down the wires straight into the compression post, thru the hole in the floor at the base of the mast and into the support block under the post. When I rewired our mast, I put a 'drip loop' in the wires before connecting them to the wires from inside. (Drip Loop: A loop of wire so water will drip off the lowest point and not travel back up the other side.) If you have not done so, you should drill a small hole into this block from the bilge and see if it is rotted. I thought ours was fine (fiberglass covering looked to be in good shape) but when I drilled into it a mess like wet coffee grounds poured out. Center of block was totally rotted away. Thankfully the outer edges were still sound enough to keep the compression post from sinking into the cabin sole.

 

[jonelli]

I have internal halyards. They exit about 4-5 feet above the deck. I’m familiar with rain drip loops. Seems silly it wasn’t already done. I can’t get in there without a lot of work at the moment so caulking is what I’m doing just for now.
min assuming that all that crap in there prevented the normal amount of water from naturally seeping out in time before filling up to the conduit and that’s where it all comes in.
The OEM step plate I have does not have the cut outs for drains. That seems to be a new addition. So I’m going to put a weep hole at the bottom of the mast. I realize it’s about 1/2” above the deck, but it will be below my wire conduit. I think I caulked it up pretty good. We’ll seehow effective it is, supposed to have rain again today and next weekend.

 

[RitSim]

On my previous C30 I had the problem also. Found suggestions on-line to add a 90 degree plastic elbow on to the conduit stub. This eliminated drips coming straight down the wires. Also added weep holes as you plan.

 

[jonelli]

Update:
So, after caulking the mast wire conduit really well, I left the boat in another heavy rain. Upon return I STILL had the bilge filled up to the pump switch threshold. But this time I noticed the floor was dry, and the compression post was also dry at the bottom, unlike before where the floor was wet and squishy (I have the EVA foam floor) and the bottom of the compression post was very wet.
I decided to check the V-berth and saw that the little area in front of the water tank was as full there as it could be, and the area just before the actual bilge had a puddle too. So that means that water is flowing around the water tank and seeping into the bilge there.
I guess my anchor locker leak might be worse than I thought. Should be easy to test and fix though.
I went ahead and drilled a couple of 1/4" weep holes at the bottom of the mast. Figured it can't hurt.

 

[Ward H]

I had read about bird droppings and water getting into the mast for the top. When my mast was down I put a piece of flat stock aluminum across the top of the mast head casting to seal the top. I drilled and tapped holes in the casting so I could mount it with a couple of machine screws.

 

[sailme88]

I thought that I had a mast leak. Turns out it the the deck hatch just aft of the step.. The guano may not be from birds getting into the vertical mast, but more likely when it was unstepped and on a storage rack.. You should be able to get an extra long high speed drill bit to reach across the access ports to the opposite side and drill downward to facilitate draining. Many hardware stores rent such drill bits..

 

[jonelli]

Went to the boat today during the rains. I'm giving up on solving this problem until I can unstep the mast some time in the future.
The anchor locker leak is irrelevant and not a big deal. Water is still coming down the mast into the compression post, maybe just through the wiring, not sure. I don't know if it's doing anything bad, but I believe my soggy floor problem is simply due to some of the water not going down the compression post drain hole (didn't know there was one), instead some of it follows the wires and gets all under the bilge cover area which leads to the EVA foam flooring. Even after I caulked up the wire conduit at the deck.
Here's what I see happening. I don't know if there are more leaks around/under the step plate besides the wire conduit. I'm not even sure this isn't the intended design! It might be what was intended? I may just have some extra water seeping to the sole that shouldn't. I made a little diagram of what I've surmised:

Here are some pics of what is happening:
VBerth is okay, it's got a little water, but nowhere near the max where it could flow over into the bilge:

Here's all the places I see water coming into the boat:

I believe this is why the sole is soaked because it's all over the upper level here.

And it's seeping mostly through here, the lowest area.

Here are some videos that also explain what's going on...

I also shoved my endoscope up the wire hole and looked up inside the compression post. I can see water dripping down.
CompressionPostLeaking

 

[jonelli]

I think I'm giving up. It's a problem between the intended design and what I'd like to happen. Water comes down the mast in the wire tube. Some of the water goes out the drain into the bilge, some of the water goes down the wires and collects at the sole where the wires go through the little hatch board bilge cover and seep into my EVA foam floor.
I can't seal the wire conduit at the deck very well without pulling the mast. I made a couple weep holes at the bottom of the mast, but water still goes down the wires.
This will be a problem to deal with another day. For now, I'll just fight the water from the little bit of rain we get in SoCal.

 

[George Da Porge]

Hey jonelli,
3 years ago I needed to replace the oak block between the bottom of the compression post and the hull. The block was completely rotted and saturated with water. On my boat, the mast wires were routed through the block (maybe the corner of it) and came out in the bilge (just under the cabin sole). I had made an assumption that water must have been running down the compression post into the block. When I did this work, I ran an endoscope up the compression post (took pics and video). I would say water did run down the inside of the compression post, but it didn't appear significant to me. I was pretty surprised at how good the inside of the post looked. There is some water staining at the bottom of the post. However, at some point before we owned the boat, it was filled with water to about 2" above the cabin sole. The water was there long enough to stain the bottom of the teak in the cabin. This CP staining is about at the level.

I think the main culprit in the rotting of the oak block was a crack in its encapsulating fiberglass at the front of the bilge. See pic. I don't know how long it'd been there, but it had to be quite a while for the oak to get that saturated. When I took chunks of the block out, I could literally squeeze moisture out of it. The replacement work is shown in the other pic. BTW - the hose coming from the starboard side at the top of the bilge drains any water caught on the port side of the hull just forward of the head.

 

[George Da Porge]

Couldn't upload the video of the inside of the CP. File too large.