Maintaining drainage at mast step

[steve77]

On our boat, the mast step has a drain located approximately in the middle of the mast step to provide a path for water to drain aft into the sump.


It's not the most flattering of pictures - there is a lot of dirt and some rust, but you get the idea.

Our previous mast base had grooves cut in it to allow water to drain. They were too small for major water drainage, but they worked for minor small leaks and to prevent water accumulation. This is a photo of the mast base upside down so you can see the grooves.



Here is a photo from above of the mast step with the mast base installed. Ductwork from the heat/AC partially obscures it, but you get the idea.



My problem is we are currently replacing the mast. Sparcraft recommends a two piece mast plug and shoe for our new mast (70 feet of S1630 mast section). This mast base will block access to the drain hole and not allow water to drain. I was thinking of putting in a spacer maybe a half inch thick under the mast base and cutting a slot in it to reach the drain. Any thoughts on this idea? If so, what material would you recommend for the spacer? If you really want to make my day, I would appreciate a supplier in Lisbon who may have this material.

Cheers, and thanks!

Steve

[Cruisingscotts]

Via their literature, the system covers this making the lower drain unessessary

F-980E Mast - Internal Waterproofing
F-980E Internal Waterproofing Plug - Fwd.: F980E-WPF:
Internal Waterproofing Plugs are installed in Keel-stepped Masts to prevent water intrusion below deck. Assembly for Forward Mast Cavity consists of 2 plastic pieces carefully cut to fit Mast interior with central PVC standpipe to allow passage of electrical wires. Unit slides up from the bottom of the Mast to a point just above Deck level where a hole is drilled in Mast to allow for application of expanding foam between plastic pieces. Second hole is drilled just above upper plastic piece to allow water drainage.

[steve77]

Originally Posted by Cruisingscotts

Via their literature, the system covers this making the lower drain unessessary

F-980E Mast - Internal Waterproofing
F-980E Internal Waterproofing Plug - Fwd.: F980E-WPF:
Internal Waterproofing Plugs are installed in Keel-stepped Masts to prevent water intrusion below deck. Assembly for Forward Mast Cavity consists of 2 plastic pieces carefully cut to fit Mast interior with central PVC standpipe to allow passage of electrical wires. Unit slides up from the bottom of the Mast to a point just above Deck level where a hole is drilled in Mast to allow for application of expanding foam between plastic pieces. Second hole is drilled just above upper plastic piece to allow water drainage.

Thanks, Jake.

The internal seal for the mast is a great idea, and it will go a long way towards preventing water intrusion into the boat. But it is not the only source of water that can drain to this area.

This is a low point in the front of the boat and water could come from any number of places. For example, spillage when cleaning a water strainer, a leaking hose, rainwater from a hatch being left open, or even a failed seal on the inside of the mast. I need this drain to be open so that any water will make its way aft to the sump and the bilge pump. Otherwise it simply accumulate and stay there until I open the floorboards to see if it is dry.

Steve

[Cruisingscotts]

For that I would reccomend a aluminum plate with a passage milled fore aft and athwartship to the drain location. No worries about dissimilar metals or load bearing capabilities. You should be able to source a machine shop to make it. It has alot riding on it, pun intended, so I wouldn't mess around with wood plastic or bits and pieces to cut cost. If you don't have luck finding a machine shop try a large shipyard, via an agent, they may be able to accomidate you and most likely will have the material on hand.

[UNCIVILIZED]

In lieu of aluminum, which will degrade in said location, you could get some G10, G11 or similar www.Matweb.com
It's a high pressure fiberglass/epoxy laminate, with strength on par with aluminum, for about 2/3 the weight. And it's machinable with all of the same tools.

Or in a pinch, you might try making some yourself. Just build a small mold table, & rig up a vacuum bag system. Even a Shop Vac (Wet-Dry Vac) works in a pinch, & will let you generate 2/3 of an atmosphere or so of pressure. And you can even post cure the laminate if you like.

Push come to shove, it takes 3/4 of a page of text to explain... or a 3min Youtube video.

But if you've got aluminum on hand, just have it fabricated, & then anodized. Or barring that, powder coated.
That, or epoxy bond some fiberglass to the step's underside, to help stop corrosion down there from pooling water.

[Cruisingscotts]

The uncivilized response above makes a good point about getting the step out of the water. In looking at your blog your boat is steel, in the picture it appears that you old mast step is bolted down to a steel plate with threaded holes attached to the keel under a layer of fiberglass and ?? is this just a glass pan or is the boat internally ballasted and the glass is covering this? Is the drain plumbed to a after bilge location? A couple of concerns would be what caused the errosion of the old step and is the mast base used as a intentional bonding point to the hull. That will play a large factor in how you proceed. As above getting things out of the recess would be a good idea if possible. With the extent of the project, a new stick etc, you might consider eliminating the drain and building up the area with a small well fwd of it for a small solid state bilge pump, whale makes some tiny ones that will mount in a small recess. The switch being integral with the foot. If it was me I would send a few pics to Perry and say WTF dude? Not sure about Lisbon but I spent several months in Vigo and they had a pretty large chandlery to support all things marine.

[steve77]

Originally Posted by Cruisingscotts

The uncivilized response above makes a good point about getting the step out of the water. In looking at your blog your boat is steel, in the picture it appears that you old mast step is bolted down to a steel plate with threaded holes attached to the keel under a layer of fiberglass and ?? is this just a glass pan or is the boat internally ballasted and the glass is covering this? Is the drain plumbed to a after bilge location? A couple of concerns would be what caused the errosion of the old step and is the mast base used as a intentional bonding point to the hull. That will play a large factor in how you proceed. As above getting things out of the recess would be a good idea if possible. With the extent of the project, a new stick etc, you might consider eliminating the drain and building up the area with a small well fwd of it for a small solid state bilge pump, whale makes some tiny ones that will mount in a small recess. The switch being integral with the foot. If it was me I would send a few pics to Perry and say WTF dude? Not sure about Lisbon but I spent several months in Vigo and they had a pretty large chandlery to support all things marine.

Jake,

First, I agree that Uncivilized gave some good info on using something unaffected by water as the spacer. That is certainly a concern, and I appreciate his suggestion.

As you noted, the old mast step is bolted down. There is a thick steel plate (I think 3/4") to support the mast, with some structure under that. The plate is covered with a thin coat of fiberglass and epoxy. The boat is internally ballasted.

This boat was built in Surrey, and was the only Amazon 49 ever built. The lines were drawn by Grahamme Shannon and the interior design by Robert Perry. I'm not sure which one designed the mast step, or if that detail was left to the yard.

The boat has a depression in the area of the mast step. This is the low point of the boat forward of the salon. All water from any leakage will collect in this area. (Leakage aft of the salon collects in the bilge sump behind the engine). The boat was built with a plastic pipe that was routed from the bilge sump behind the engine, forward to the base of the mast. During construction, they forgot to drill a hole under the mast step to connect this drainage pipe to the mast step area. The erosion of the original mast step was caused by it sitting in water for expended periods. When we bought the boat there was six inches of water sitting there.

We remedied this during a haul out when we pulled the mast. We drilled the hole you see in the photos, snaked a hose down to make sure it connected to the pipe, and sealed around both ends of the hose with 5200.

I had not considered reworking the mast step area. To be honest, it would be more engineering that I want to do. I can visualize a way to do it, but it would require raising the mast base a good six or eight inches, and then resurfacing everything to route water to the new collection point. It's an idea I hadn't considered.

Thanks for the suggestions. Cheers!

Steve

[carlheintz]

I'm all in with Uncivilized's response. DON'T use aluminum or any dissimilar metal. It WILL, guaranteed, WILL degrade over time. Salt + water + dissimilar metal ( even a dissimilar alloy) will cause electrolysis. Guaranteed. No way to stop that with coatings, powder or otherwise, when you have a mast that will constantly be flexing ever so slightly. This is a critical load bearing location, which is mostly hidden from view, checked only ever so occasionally, and something that could cause catastrophic failure.

Also, I love the manufacturer's assertion that you don't have to worry about water getting down there... HA! My Cal 28 is a deck stepped mast and it's amazing how the "proven technology" of sealing things just fails over time, especially in places you can't get to without pulling the stick. My "100% guaranteed water seals" for cable going through to the cabin fail regularly.

Plan on the worst and be pleasantly surprised.

[Terra Nova]

Originally Posted by steve77

...The boat has a depression in the area of the mast step. This is the low point of the boat forward of the salon. All water from any leakage will collect in this area. (Leakage aft of the salon collects in the bilge sump behind the engine). The boat was built with a plastic pipe that was routed from the bilge sump behind the engine, forward to the base of the mast. During construction, they forgot to drill a hole under the mast step to connect this drainage pipe to the mast step area. The erosion of the original mast step was caused by it sitting in water for expended periods. When we bought the boat there was six inches of water sitting there.

We remedied this during a haul out when we pulled the mast...

As long as this is allowed to drain completely you're OK.

[UNCIVILIZED]

My cruising friends/neighbors had a (steel) Colvin Gazelle. And while it took on like ZERO water, they still had a "unique" bilge sump... out of necessity.

She was junk rigged, with totally sealed spars. The spars themselves, as well as where they penetrated the deck. Plus she had a dripless shaft seal. Still...

The bilges were setup so that any water in them; from condensation, or "other", drained to a purpose built sub-sump. Which was even lower than the bilges/main sump level.
And in it, they alternated (over time) between; a purpose built, glued in (with silicone), fiberglass pan, or a plastic dish sink sized basin (usually glued in, similarly). And they would swab it out with a large sponge, with a religious fervor. Daily, or even more often.

As, even in a VERY welll designed & built, steel boat, they HAD to keep the water out (of her). And this was their normal daily practice, even when on the hook for weeks at a time.

So keeping a metal boat dry, IS a Very serious issue.

[steve77]

Thanks, everyone. I ordered a 12" x 12" x 1/2" pice of G10 to use as the spacer under the mast base. It should be here in time for us to head back to Lisbon next week.

This should allow us to keep things dry and dusty at the mast step area.

Special thanks to Uncivilized for the G10 suggestion. Cheers!

Steve

[kristjan]

Originally Posted by UNCIVILIZED

My cruising friends/neighbors had a (steel) Colvin Gazelle. And while it took on like ZERO water, they still had a "unique" bilge sump... out of necessity.

She was junk rigged, with totally sealed spars. The spars themselves, as well as where they penetrated the deck. Plus she had a dripless shaft seal. Still...

The bilges were setup so that any water in them; from condensation, or "other", drained to a purpose built sub-sump. Which was even lower than the bilges/main sump level.
And in it, they alternated (over time) between; a purpose built, glued in (with silicone), fiberglass pan, or a plastic dish sink sized basin (usually glued in, similarly). And they would swab it out with a large sponge, with a religious fervor. Daily, or even more often.

As, even in a VERY welll designed & built, steel boat, they HAD to keep the water out (of her). And this was their normal daily practice, even when on the hook for weeks at a time.

So keeping a metal boat dry, IS a Very serious issue.

My Colvin is similar, used to be a shower and sink drain collection and deck mounted Edson pump to remove, now it is a sealed collection with float switch and the sump is greased.