Remove stuck through hull

[Tmacmi]

The through hulls that drain my cockpit are made of nylon. They do not have the "ears" in the outlet to enable the traditional wrench to be used. The only have slits in the edges that require using a large washer on its edge to remove. That does not provide enough torque to loosen.

How do you recommend getting rid of them and avoid damaging the fiberglass of the hull?

Use a step drill bit?

Use a dremel cutting tool in the outlet?

[Ivanvet]

Hi,
I removed all the trough hulls of my boat in a couple of hours by just using a wooden bung from the outside, a mallet and a drill with a hole saw. Just like this...
https://www.sailmagazine.com/diy/boa...y-through-hull

This guy shows very well how it's done. I think it's in Norwegian but the video is self explanatory

https://www.youtube.com/watch?v=Tysi4ScnZ_w

Cheers,

Ivan

[HobieDog]

Originally Posted by Ivanvet

Hi,
I removed all the trough hulls of my boat in a couple of hours by just using a wooden bung from the outside, a mallet and a drill with a hole saw. Just like this...
https://www.sailmagazine.com/diy/boa...y-through-hull

This guy shows very well how it's done. I think it's in Norwegian but the video is self explanatory

Cheers,

Ivan

Great video, thanks for sharing! I really like the idea in theory but a little unsure of my ability to get the hole saw perfectly centered. Looks like it worked well for this guy.

I need to replace a total of 5 thru-hulls that are above the water line before launching this season and was planning on using the puller method to extract them. See attached, Tmacmi, for another method.

[Tmacmi]

Originally Posted by HobieDog

See attached, Tmacmi, for another method.

Originally Posted by Ivanvet

This guy shows very well how it's done.

Ivan

Thanks to you both! Hobie dog. Not only is the mushroom head locked, I can't get the nut loose from the back side.

Here's how to find the center of a circle!

https://www.youtube.com/watch?v=UUL24IdUrkU

[Ivanvet]

Yes, I still remember this video from my woodworking times.

https://www.youtube.com/watch?v=6q9jE6rvOWE

[vpbarkley]

I plan to use a large countersink in an electric drill. McMaster sells them.

I have 22 brass through hull fittings to remove.

I have seen videos using a Dremel, an angle grinder and a hole saw.

With those tools you could potentially damage the hole through the hull.

I think a large countersink greatly reduces the chance of that happening.

And, if you do contact the hull you only chamfer the hole edge.

A countersing self centers in the bore of the through hull fitting.

[Oceansailor]

I have used the hole saw method many times. Centering can also be done if you use two hole saws at the same time. Inside the bigger one you put a smaller one with the same diameter as the inner diameter of the thru hull. It can actually be loose insede the bigger one as it is only used for centering the hole saw.

[Paul Howard]

Using a sawsall reciprocating saw blade up through from the bottom and make a couple cuts through the wall of the old thru-hull, then hammer, chisel, or whatever to knock out the pieces.

[s/v Jedi]

Originally Posted by Paul Howard

Using a sawsall reciprocating saw blade up through from the bottom and make a couple cuts through the wall of the old thru-hull, then hammer, chisel, or whatever to knock out the pieces.

+1 I use a Fein Multimaster and plunge cut straight up the fitting. Only takes a couple of minutes to remove the fitting.

[Tmacmi]

Thanks to everyone! Very pleased to say that using the bing and hole saw worked perfectly.

Each one took 10 min.

[slug]

Originally Posted by Tmacmi

The through hulls that drain my cockpit are made of nylon. They do not have the "ears" in the outlet to enable the traditional wrench to be used. The only have slits in the edges that require using a large washer on its edge to remove. That does not provide enough torque to loosen.

How do you recommend getting rid of them and avoid damaging the fiberglass of the hull?

Use a step drill bit?

Use a dremel cutting tool in the outlet?

Plug the thru Hull hole with a wood bung

Drill a pilot hole thru the center of this wood bung

Then fit the same size hole saw that originaly bored the hull for the fitting

Use the pilot hole in the wood bung as a guide and cut thru with the hole saw ... from the outside

[osprey877]

Originally Posted by s/v Jedi

+1 I use a Fein Multimaster and plunge cut straight up the fitting. Only takes a couple of minutes to remove the fitting.

+1 Quick and easy. The only problem I had fitting the new through hulls was that there wasn't enough room on the inside of the hull to screw the valve down onto the through hull from the inside as the handles got in the way of each other. So I had to screw the through hull into the valve from the outside. This makes it difficult to get a good sealant base under the through hull. However, after a few anxious moments at splash down, it all worked out and hasn't leaked yet (touch wood).

[pcmm]

Originally Posted by osprey877

+1 Quick and easy. The only problem I had fitting the new through hulls was that there wasn't enough room on the inside of the hull to screw the valve down onto the through hull from the inside as the handles got in the way of each other. So I had to screw the through hull into the valve from the outside. This makes it difficult to get a good sealant base under the through hull. However, after a few anxious moments at splash down, it all worked out and hasn't leaked yet (touch wood).

Screwing the thruhull into the seacock from the outside is the normal way to do it if you are installing them correctly. A seacock needs to be bolted to its backing plate first and then the thruhull installed from outside. If you are screwing a valve onto a thruhull, your installation is incorrect.

[osprey877]

Originally Posted by pcmm

Screwing the thruhull into the seacock from the outside is the normal way to do it if you are installing them correctly. A seacock needs to be bolted to its backing plate first and then the thruhull installed from outside. If you are screwing a valve onto a thruhull, your installation is incorrect.

I know it’s incorrect. That’s why I said it was a problem. But if the interior space is too cramped to allow the seacock to be rotated through 360 degrees, then there are not many alternatives. I epoxied the backing plate to the hill, then dry fitted the through hull to the seacock, bolted down the seacock, then unscrewed the through hull, applied sealant and rescrewed it back in. So far, so good.

[pcmm]

Originally Posted by osprey877

I know it’s incorrect. That’s why I said it was a problem. But if the interior space is too cramped to allow the seacock to be rotated through 360 degrees, then there are not many alternatives. I epoxied the backing plate to the hill, then dry fitted the through hull to the seacock, bolted down the seacock, then unscrewed the through hull, applied sealant and rescrewed it back in. So far, so good.

When installing a seacock there is no need to rotate it through 360 degrees (even, if its a proper flanged bronze seacock, or marelon excepting the OEM style). It simply bolts in place on the (typically) 3 bolts that hold it to the hull/backing plate. then the thruhull is screwed into it from the outside.