Dodgy through hull picture - should I panic?

[[2574]]

I've brought this thread back to life because today I've had all of the through hull fittings with the valves and hosetails removed from our hull. You might recall that we are talking of an twenty year old Nauticat here with brass valves and associated fittings. I'm replacing with bronze through hulls and hosetails with DZR valves. I though you might like to see some of the old fitting photos so here goes:

1) Picture of the through hull from outside the hull after the flange has been chopped off:

2) Picture of a through hull that has been removed:

3) Picture of one of the hosetails:

4) Second picture of the hosetail:

General observations are that the original brass seems to now be very brittle and seems to have a coarse texture. The colour you can see for yourself. The hosetail in the picture seems to have only a paper thin wall of malleable material around the outside of the original fitting with the inner surfaces seemingly turned brittle and breaking up. There is no strength to the inner hosetail material, it can be broken up by rubbing between the fingers.

Having seen this today I am pleased that I decided to go ahead and replace the lot, I think we can agree that the fittings are past their best.

Rob

 

[Dipper]

Thanks for the update on this. Too many threads end halfway through and nobody learns anything from them.

I'll leave those more knowledgeable than me to comment.

 

[doug748]

Thanks for the update on this. Too many threads end halfway through and nobody learns anything from them.

I'll leave those more knowledgeable than me to comment.

I agree, thanks.

Your 20 year old Nauticat looks immaculate BTW. They do look knackered - do you know for sure that they were bog standard brass?

 

[[2574]]

I agree, thanks.

Your 20 year old Nauticat looks immaculate BTW. They do look knackered - do you know for sure that they were bog standard brass?

Thanks, I see that you're local - do come and make yourself known if you see us kicking about. Fat bloke, thin wife!

Yes confirmed brass - I consulted with Nauticat (they maintain records of every boat ever built) and also the makers of the valves, Hogfors, who were very helpful.

rob

 

[GrahamM376]

I think some of you are getting a bit paranoid.

You still think that having seen the photos?

 

[vyv_cox]

Excellent, thanks for posting them. May I use a couple of them please?

 

[[2574]]

Excellent, thanks for posting them. May I use a couple of them please?

Vyv,

Help yourself, there will also be more pictures to come over the next day or so if you'd like other examples.

The valve that started this thread, seen at the first post above, is coming out tomorrow. As this was the particular focus of the discussion I will photograph that one and post it up tomorrow evening.

Rob

 

[mjf107]

Thanks for the update on this. Too many threads end halfway through and nobody learns anything from them.

I'll leave those more knowledgeable than me to comment.

+1

 

[grumpygit]

Vyv might be able to give an opinion on this . . . . I don't know if this is a good test but it may be a guide. An old marine engineer I knew gave the base of the sea cock a tap with a hammer. If the sound coming back was quite high in frequency he assumed all was good but if the return sound was a low dull thud he would mark it down for replacement. I used to do a similar test in the line of my work by dropping certain objects on the floor and if it didn't sound right I would inspect for cracks. And there always was cracks.

 

[vyv_cox]

Vyv might be able to give an opinion on this . . . . I don't know if this is a good test but it may be a guide. An old marine engineer I knew gave the base of the sea cock a tap with a hammer. If the sound coming back was quite high in frequency he assumed all was good but if the return sound was a low dull thud he would mark it down for replacement. I used to do a similar test in the line of my work by dropping certain objects on the floor and if it didn't sound right I would inspect for cracks. And there always was cracks.

Yes, a sound(!) method but it does take experience to judge. Paul Stevens, who was the surveyor who first raised awareness of the problem in YM, http://www.paulstevenssurveys.com/upload/Seacocks.pdf tests seacocks and fittings in exactly that way. He uses a light hammer and a small screwdriver to direct the blow where he wants it. Sometimes the screwdriver goes right through but on other occasions he makes a judgement based on the sound.

 

[[2574]]

As promised here is a picture of through hull that started this conversation. The through hull feautured (as pictured in the first post with subsequent improved photography in later posts) has been removed and the below is a cross-section photo of the same through hull fitting. I've kept the photo fairly large so that you can see the detail of the image. If anyone wanted an HD version then PM your email address and I'll send it over.

The outer shiny material is the fitting thread, the inner material which appears more matt (and appears a brittle and coarse structure with little strength) is the core of the through hull fitting.

All good stuff to further our knowledge!

 

[NormanS]

As promised here is a picture of through hull that started this conversation. The through hull feautured (as pictured in the first post with subsequent improved photography in later posts) has been removed and the below is a cross-section photo of the same through hull fitting. I've kept the photo fairly large so that you can see the detail of the image. If anyone wanted an HD version then PM your email address and I'll send it over.

The outer shiny material is the fitting thread, the inner material which appears more matt (and appears a brittle and coarse structure with little strength) is the core of the through hull fitting.

All good stuff to further our knowledge!

It all looks like a good argument in favour of "plastic" fittings.

 

[mjf107]

As promised here is a picture of through hull that started this conversation. The through hull feautured (as pictured in the first post with subsequent improved photography in later posts) has been removed and the below is a cross-section photo of the same through hull fitting. I've kept the photo fairly large so that you can see the detail of the image. If anyone wanted an HD version then PM your email address and I'll send it over.

The outer shiny material is the fitting thread, the inner material which appears more matt (and appears a brittle and coarse structure with little strength) is the core of the through hull fitting.

All good stuff to further our knowledge!

Hi and the thanks for the update, when you posted the original photo it looked immaculate to me, just shows how wrong you can be! Top marks for a job well done

Michael

 

[Tranona]

It all looks like a good argument in favour of "plastic" fittings.

Or DZR rather than plain brass.