Through hull sealant that can go in water before cured

[GordMay]

Originally Posted by Chris Cringle

If you use 5200, it will never come off. I would use BoatLife Life Caulk. Cures under water. Seals well. Comes off when you want it off.

BoatLIFE Life-Calk is a polysulfide [thiokol] sealant, that can be applied underwater.
Many Polysulfide sealants, including Life-Calk, require a primer.*
* Step 3 ➥ https://www.boatlife.com/wp-content/...lkR-1-PART.pdf

[Fuss]

Originally Posted by Fore and Aft

Jim you are so right, I have used Sikaflex to install plenty of skin fittings. Often while the boat is hanging in the slings and then straight back in the water. Never had an issue or else I would have looked for another sealant. I suppose that's why all those words are on the back of the tube, one of these days I will get around to reading them.
Cheers

Well you're not quite right Fore and Aft....
let me explain...
If you sika an underwater component and then the next day splash the boat then the sika will never cure and remain like chewing gum. Of course in the case of your skin fitting, you do not know this as the Sika is under the skin fitting right, not available for you to touch.
The only reason that I know this is that I was testing along time ago and had excess sika on the outside of the skin fitting, then splashed the boat the next day.
It's probably not a bad thing..a bit of chewing gum under the fitting!

Its all in the Sikaflex instructions should you care to read them...

[Redline452]

Originally Posted by belizesailor

Real men replace the thru hull in the water!

Actually, I have done that, though not the entire thru-hull (and this may be your case). It was a Marelon fitting that was overly tight and the handle snapped off - actually the square shaft on the ball that the handle fits over broke.
I bought a new fitting exactly the same as the existing one, inserted a wine cork in the opening from the outside. I then unscrewed the inner part of the valve, leaving the thru-hull portion in place, and installed the new valve side. IIRC I then pushed the cork out through the open valve from inside with a screwdriver, closed the valve and reconnected the hose.

[Warren149]

Why wouldn’t you use butyl sealant ? It never cures anyway .

[jakkum]

Originally Posted by Jim Cate

I believe that most of the polyurethane sealants will cure underwater...

Jim

if the old one can still be opened perhaps Reith difficulty and it has thread on the inside, find a suitable peace of plumbing and mount a second valve pn there
By the time you are dry somewhere, you can set things right.

[Goodxcharly]

I agree with the fast cure option Don’t splash till cured, 1 hour.
I have used the slow cure, splashed the boat. Water seepage, small and liveable, not like the boats going to sink.
There is pressure on the uncurled sealant and depending how well seated the thru-hill is can push the sealant out.

[SomeGuyInaShirt]

Originally Posted by Chris Cringle

If you use 5200, it will never come off. I would use BoatLife Life Caulk.

I used boat Life Life 'calk' on my keel hull joints and they still leak. I'm curious to know what you used it on that was satisfactory. Boat Life will never see another dime from me.

[Don C L]

Originally Posted by Warren149

Why wouldn’t you use butyl sealant ? It never cures anyway .

True, but that is its weakness too. Where I have used butyl it continues to ooze after you think you have snugged down the joint and then the joint becomes less than snug.

[Kello]

Polysulfide is water cure, splash immediately. Don't know of any existing brands except Boat Life, and their quality is ... ok.


What you didn't say is what your fitting is made of - bronze or plastic. Bronze, use polysulfide or 3M 4000 or 4200, forgot which is best. Plastic, do not use polysulfide, only the 3M product/s.


Anybody who tells you to use 5200 is either naive or hates you.
NEVER use butyl rubber tape below the waterline.


Schedule your haulout at 11:AM or just before lunch, that way you get two hours in the slings.

[Celestialsailor]

The fittings I will be using is made from bronze.

[Kello]

Forgot to mention, if your boat's PO was stupid/ignorant/gullible enough to use 5200 on the current fitting, you won't be able to renew it in an hour or two. Schedule your haulout when the yard has time and room to block your boat for a day or two to remove the broken fitting.

[Trimaran Ken]

Originally Posted by Chris Cringle

If you use 5200, it will never come off. I would use BoatLife Life Caulk.

Use 3M 4200. Almost as strong as 5200 and it is possible (with difficulty) to remove down the road.

[OneBoatman]

I would probably use 3M 4200 fast cure. I suspect you may need a little more time in the slings than you think because first you must release the old, clean the surfaces, and then install the new. On fiberglass I use lacquer thinner, not acetone for cleaning. There is a distinct difference between replacing a bronze seacock which is one piece, which may have been installed as it should typically with 3 silicon bronze bolts, and replacing a thru-hull fitting and ball valve (two pieces). I'm guessing you'll need two hours in the slings, maybe less, depending on how quick you are. Some marinas may let you hang overnight at no extra charge. Make sure you have everything you need before you're hauled.

[s/v Jedi]

The story about not being able to remove fittings when 5200 was used is a myth. Here is how to do this:

Put two hole saws on a single arbor. First the large one of the diameter used for the hole through the hull, then the small one that just fits inside the old fitting.

Start drilling until you have a good start on the flange. Now remove the smaller hole saw and continue with just the big one until you cut through the flange. Use a hammer and chisel to remove the flange.

When you remove the seacock/valve on the inside, I normally continue to use the hole saw until the fitting is pushed through. If that doesn’t happen, simply drill all the way through. Doesn’t take more than a couple of minutes.

I have one leaking fitting and this is where I used polysulfide. It is just above the waterline but it is a plastic fitting. I now only use 5200, the one that takes 7 days to cure. I believe it’s best to let antifouling cure for a minimum of 5 days so fits the schedule perfectly.

That said, for immediate launch this won’t work and I have no experience with that.

[Bowdrie]

If I had to replace a bronze thru hull whilst in the water, I would use 5200 without a second thought.
As to its permanency with that use?
No, applied against a dirty wet surface, (underwater,) does not result in the same level of adhesion as would be so if used on a dry surface which has been abraded and chemically cleaned with Acetone/Alcohol.
Anyone afraid of difficulties in removal, (or ease of installation,) needs a thru hull wrench.
The little "T" handle works for installation.
Even with 5200, when you put a big wrench on the flats that thru hull will come out.