Pourable, flexible, watertight caulk or sealant needed for difficult-to-access area

[suenodelmar]

We need a pourable, flexible sealant to make a watertight seal within a space that is difficult to access. The area has some dirt that is not fully removable. So, the sealant needs to be very thin in order to penetrate and adhere to the surfaces. It also needs to remain flexible so that vibration will not break the watertight seal.

Liquid resin or epoxy would set too hard and inflexible. Standard polyurethane caulk would be too thick, failing to penetrate and seal some areas, especially where some dirt remains.

We have thought of two alternatives:

1. The flexible sealant that comes in a spray can.* One brand is advertised on TV.* Hardware stores often carry similar products.

2. The pourable "tool handle grip" rubber-like material that is designed for dipping the handles of your pliers, etc.*

Any other ideas?

[Ribbit]

Hmm, you'll have a problem if there's any dirt left, as there's probably grease as well.

Can you steam clean it out with a small steam cleaner?

Does the area have to resist water pressure at all, and how many sharp corners?

Once properly clean you could spray glue it, and if no water pressure, inflate a heavy duty balloon (weather balloon type) to stick onto the spray glue? Probably have to find a suitable spray glue, and a suitable balloon material (though could use a waterproof dry bag to inflate, maybe even with a balloon inside it to help it along).

Once glued in solid, just trim as necessary.

If you can get round it with a brush, that Evostick stays flexible, and sticks well too.

[MarkJ]

Mast boot resin.

Its a 2 part flexible resin designed to be poured into a mast boot that penetrates the nooks and crannys to keep water from entering the cabin whilst allowing the mast to move.

[roverhi]

Liquid LifeCaulk cured a PITA leak in an area that I couldn't get at on my last boat. It's a semi liquid version of their Polysulfide LifeCaulk. There is also a liquid caulk from England that I can never remember the name of. It's something Captain So and So's leak fixer. Think it's now available here in the States but, once again, don't know the source.

Agree with advice to get the area as clean as possible.

[UNCIVILIZED]

I've got a recipe for thinning out RTV (sealant) which might work. But as stated already, the bonding area needs to be clean & dry.
For that, a pressure washer, followed by a wet/dry vac, & then a space heater should do the trick... If the area can withstand the forces which a pressue washer generates, that is.
If not, then you're stuck cleaning it the old fashioned way. Even if that means lashing long & or curved handles onto your cleaning tools.

[suenodelmar]

Thank you for the excellent and thoughtful responses. The area in question is inside my mast at the base where the mast wires penetrate the mast step through small holes drilled in the bottom. water has been leaking down through those holes for years, undetected, before I bought the boat. The only access is a three-quarter inch hole in the side of the mast located about 3 inches from the base. I have looked at the area with an inspection camera. There is a lot of dirt and sand-like material. I have been drying out the area with a paddle fan connected to a cone and tube inserted through the three quarter inch hole. I can arrange a way to vacuum out the worst of the dirt. But I do not know how to remove the remaining dirt and possible grease. It would be almost like arthroscopic surgery!

I think that you are all right about the need to remove the grease and the possibility of steam cleaning. I would need some kind of micro steam cleaner and vacuum to penetrate the three quarter inch hole. Sort of like the snout of a Rug Doctor made for Hobbits.

I hesitate to fill the area with too much moisture. I suppose that I temporarily could block off the drainage channels from below with some caulk or dum dum. I hesitate to wet the area inside the cabin another time. But that may be necessary.

Any further ideas on how to clean out the dirt and grease from the area and then inject a sealant?

[goat]

Never tried it but what about something like this stuff;

Home Hardware - 340g Window & Door Insulating Foam Sealant

It would be a pain if you ever had to remove it. You don't want to be that PO.

goat

[Jubilee39]

The Captains Creeping Crack Cure is badically latex. I have stopped leaks in the base of a mast by simply pouring in a small amount of latex paint. You might have to use rags to catch the drips initially but build it up over several days

[kas_1611]

Slightly on a tangent -
Would Captains Creeping Crack Cure work to seal the edge between a hatch and hull?

I have one side hatch that the original sealant has slowly but surely "oozed" from one side. So far I have been able to keep it sealed through the simple process of stuffing the sealant back in the gap with a very small screwdriver but would like to find a more permanent solution. Note it doesn't physically leak but does look unsightly.

Back to the original question: could you clean the grease and gunge from the space using dry cleaning fluid (or other such solvent)? Spray it in to dissolve the gunk and using an oil extractor pump suck out as much as you can then leave the residual to simply evaporate. Would help dry out the area as well prior to sealing. Admittedly it might be a little fumey for a day or so. Just an idea.

Keiron

[exMaggieDrum]

Suenodelmar, you don't mention what country or location you are at. In the US you can get Captain's CCC at WM: Captains Creeping Crack Cure

The website (in England) says the area must be free of dirt and grease. I haven't tried it but might get some.

[MCOS]

Originally Posted by suenodelmar

We need a pourable, flexible sealant to make a watertight seal within a space that is difficult to access. The area has some dirt that is not fully removable. So, the sealant needs to be very thin in order to penetrate and adhere to the surfaces. It also needs to remain flexible so that vibration will not break the watertight seal.

Liquid resin or epoxy would set too hard and inflexible. Standard polyurethane caulk would be too thick, failing to penetrate and seal some areas, especially where some dirt remains.

We have thought of two alternatives:

1. The flexible sealant that comes in a spray can.* One brand is advertised on TV.* Hardware stores often carry similar products.

2. The pourable "tool handle grip" rubber-like material that is designed for dipping the handles of your pliers, etc.*

Any other ideas?

I would not recommend the spray sealant in a can. Great for use on a roof to seal around flashings but I think you will find it rather messy and not visually appealing. Try Captain Tolley's Creeping Crack Sealer. It is a thin liquid which flows into seams, cracks etcetera. I used this on a persistent seeping leak around a hatch and it worked quite well. Most of it seeps or wicks into the gap and it dries translucent. You can paint over it when it dries. There is also a liquid silicone product that RV dealers use to seal around roof fittings on RV's that might do what your interested in. It is pourable and dries to a rubbery, flexible condition.

[seasick]

Flex Seal as seen on TV is garbage. As I envision your situation, your mast is stepped on deck. Sounds as though you have a fair amount of aluminum oxide within the mast.

The only sure cure is to reroute the wires out of the side of the mast and down through the cabin top with appropriate compression fittings and permanently seal off the old holes the next time you pull the mast.


If you insist on just pouring in the mucky-muck be certain that any future water has an exit or your mast will fill with water and you'll capsize at the dock. Of the suggestions given thus far, Goat's idea of the spray polyurethane foam seems the most likely to succeed.

Until you pull the mast, I would focus on where the water is getting into the mast rather than on where it is leaving the mast and getting into the cabin.

[senormechanico]

Originally Posted by roverhi

Liquid LifeCaulk cured a PITA leak in an area that I couldn't get at on my last boat. It's a semi liquid version of their Polysulfide LifeCaulk. There is also a liquid caulk from England that I can never remember the name of. It's something Captain So and So's leak fixer. Think it's now available here in the States but, once again, don't know the source.

Agree with advice to get the area as clean as possible.

Captain Tolley's Creeping Crack Cure

Captain Tolley's Creeping Crack Cure Leak Crack Sealer 2 FL Oz | eBay

[wrwakefield]

Originally Posted by suenodelmar

We need a pourable, flexible sealant to make a watertight seal within a space that is difficult to access. The area has some dirt that is not fully removable. So, the sealant needs to be very thin in order to penetrate and adhere to the surfaces. It also needs to remain flexible so that vibration will not break the watertight seal.

Liquid resin or epoxy would set too hard and inflexible. Standard polyurethane caulk would be too thick, failing to penetrate and seal some areas, especially where some dirt remains.

We have thought of two alternatives:

1. The flexible sealant that comes in a spray can.* One brand is advertised on TV.* Hardware stores often carry similar products.

2. The pourable "tool handle grip" rubber-like material that is designed for dipping the handles of your pliers, etc.*

Any other ideas?

Suenodelmar,

Here are a couple of options that may work for you. [I'll provide US based links not knowing where you would be purchasing from/shipping to...]

First, if you haven't already, I would insert whatever size hose you can in the access hole, tape that to your shop vac hose, and see how much of the debris you can remove.

Then consider one of the following self-leveling elastomeric sealants:

Dicor Self-Leveling Lap Sealant is what we use on our rubber membrane roof on our truck camper. Works great and lasts forever. Truly self leveling and probably the cheapest solution.

Sikaflex 2C SL Polyurethane Elastomeric Sealant [2 part] is purpose made self-leveling for underwater construction joints , etc.

Best wishes accomplishing your goal.

Cheers!

Bill

[Scaramanga F25]

Are you trying to plug up the mast weeping hole that is there at the mast step. It may be a small notch that ensures that the mast does not fill with rain water that comes in through the mast head?