Internal Alu Mast sealing.

[Robbie.g]

We're talking internal mast leaks, on a 15yo keel step mast, looks like a painted alu fosters section.
So having delt with all the usual suspects, wiring tube (top end and all other entries), the swisscheese of a mast cap, hosed around the deck gaiter etc. there is still water commin in, definately internally. Opted for the internal seal, just below the lowest exit, found signs of a previous go. .etc etc
The chase; below is what i currently do, and what i use. I'm looking to improve the process, and the reliability, so i'm interested in what you guys do, and /or any ideas.

My current procedure when the mast is in place, is to drill a hole just lower than where i want the finished seal to be, (usually at the lowest exit),hose out and leave to dry; then insert a balloon and blow it up, this fills most of the void (except around the wiring conduit edges). I then squirt/pour in Selleys Allclear, this usually, mounds in the center then slides down adhere to the mast wall and the small voids around the conduit; Success depends on the tempreture real warm (skins too early and stays as a mound), or too cool (stays as a mound too thick to run). when cured I then add an other layer and remove the balloon. Works 1st time 8/10 times, although some, dispite my best efforts take 2/3 goes.
The re-works are killing me.

Cheers in advance.

[Asylum]

Whenever I hear about a method to seal a keel stepped mast I wonder whether the solution may be worse than the problem.

Will having a trapped pool of salt water sitting inside a mast section potentially increase the risk of internal corrosion?

I don't just sit here and wonder about this kind of stuff. I ask because I lost a friend in an airplane accident years ago that was caused by corrosion from trapped moisture in the wing support strut of an airplane. The strut was steel, not aluminum and in all likelyhood it was not internally coated with zinc-chromate.

We get water down our mast via halyard openings whenever there is significant rain, but most of it just drains into the bilge and the rest get's wiped up.

[Robbie.g]

I totally agree having a pool of water trapped in mast is probably not all that good.
I should have been clearer... The internal seal is normally fitted at the lowest halyard exit, so any water pours out the exit onto the deck.
As for water inside the boat, seem there are few newer boats built with a bilge as our grandfathers would know, where water in a boat was par-for-the-course; many of the evermore popular cruiser-racers boats have very shallow bilges (well space below the floorboards) that with the slightest amount of water and heel, anyone below gets wet feet, or the carpet gets wet!
Also i guess that there are more owners who don't nip out to 'check' on the boat periodically, they just want to turn up, having left the boat for a time and sail away.
Maybe it's a sign of the times or the way things are heading.
I was hoping that someone may have a 'magic bullet' product for the sealing, any hands up?

[Brian Duff]

follow the selden example.

pull the rig, insert a dam that is made of 3/4" plastic/foam with a short (12") conduit in the center of it. Slide it coated in sealant up the rig to just above the mast boot. Rivet it in place. make a few 3/8" holes around the mast just above the dam, sometimes there is a hand access hole here but i don't belive on selden rigs there is. seal above the dam with sealant applied via a copper tube worked through these small holes. The wiring inside the rig either goes down with a drip loop, up and into the center conduit, or outside of the rig, at this point.

that help?

the copper tube is the real trick, good luck!

[Robbie.g]

thanks brian, i think your right the multiple holes and the copper tube is the trick. I've been working with the sealant and a plastic tube taped to some alu welding rod, but getting to the back of the wiring tube is always the hard bit, a hole on the opposite side is also the go.

And yes your right on the pull the mast, and insert a slab of foam is the go, i use 2 sheetsof foam cut around the wiring tube, (tight fit), one to just below the finished level, push up a 2nd covered in poo when they meet the poo squirts out to the edges this glues and seal them in place. I then pour in the clear seal, this works about 99% of the time. But with your ideas, the mast in fix with another hole or two to get to the back of the wiring tube with a copper tube is the best solution. .
Thanks for your input brian