Mataji
Well-Known Member
A ditty I saw recently on this forum comes to mind. The one about the 4 categories of sailors:- dead; retired; novices and pessimists. Wise words.
Dodgy through hull picture - should I panic?
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ghostlymoron
Well-Known Member
Old sailors or bold sailors not both.
ghostlymoron
Well-Known Member
Pcatterall, someone should tell you where to stick your borescope!
fireball
Well-Known Member
This is where you do want a camera with remote viewer on it ...
Like a GoPro with wifi and the app on your phone/tablet
or
do a skype video call between two mobiles
then you can have a good prod'n'poke about whilst looking at the result.
Me - I wouldn't panic, but I'd want to find out if that was the nut that had broken off - if so I'd be looking at a sooner rather than later fix ...
Like a GoPro with wifi and the app on your phone/tablet
or
do a skype video call between two mobiles
then you can have a good prod'n'poke about whilst looking at the result.
Me - I wouldn't panic, but I'd want to find out if that was the nut that had broken off - if so I'd be looking at a sooner rather than later fix ...
bikerbill
Well-Known Member
Looks not too bad considering it could be alright for years to come, but being me, I would get the boat out then either replace
or repair if only for piece of mind. While the boat is out, you find work to do like give the hull a scrape and apply AF if required.
or repair if only for piece of mind. While the boat is out, you find work to do like give the hull a scrape and apply AF if required.
pcatterall
Well-Known Member
OOH ER!! probably not a pretty site!!
vyv_cox
Well-Known Member
The valve, being unplated, is either bronze or DZR. I don't see any CR markings which suggests that bronze is more likely. The skin fitting and hose tail are unlikely to be DZR at the age they are and the visible corrosion product suggests that they are probably leaded brass. At five years old they are just reaching the age at which the boat builder can sit back smugly, knowing that they have reached the life required of the ISO standard. The reality is that they just might be on the point of failing.
My initial action would be to heave heavily on the hose tail, working it from side to side to ensure that the skin fitting does not fracture. That will pretty much guarantee you one season. If this approach is not sufficient for your peace of mind I would replace the skin fitting and hose tail with bronze, not terribly expensive from ASAP and others.
See Brass and Bronze on my website for more info and examples.
My initial action would be to heave heavily on the hose tail, working it from side to side to ensure that the skin fitting does not fracture. That will pretty much guarantee you one season. If this approach is not sufficient for your peace of mind I would replace the skin fitting and hose tail with bronze, not terribly expensive from ASAP and others.
See Brass and Bronze on my website for more info and examples.
nimbusgb
Well-Known Member
At first glance it appears that there is a facet missing off the nut but that is not the whole story.
The real fitting is the through hull fitting itself. It comes through the hull from outside and will be bedded into the hull with sikaflex or something similar. It may even be a tight enough fit to have been threaded in to the glass layup. That nut is probably doing very little at this stage anyway, it would have held the through hull in place, nice and square to the hull, while the sealing agent cured. Chances are its actually an ABS or similar high density plastic nut rather than a bronze one. ( which is why it broke in the first place ) 5'll get you 10 that it's been that way since the boat was delivered from the factory.
If you've ever tried to remove through hull fittings from a 'nearly mangy old plastic boat' you'd have a lot of faith in the strength of that fitting!
Even if the hull fitting was clobbered from outside it isn't going to pop into the boat, if the seal was broken it would just leak a bit and could be patched temporarily with a suitable sealing agent.
Replace the nut next time you haul if it bothers you. Take off the hose, unscrew the valve ( may need a key to hold the through hull from outside aided by a suitably large apprentice ), break the gelcoat away from the existing nut with an old chisel, unscrew the nut, clean up the surrounds, screw on a new nut bedding it on a small bead of sika. Re gelcoat and re-assemble, an hour or twos work.
What will actually happen .....
You won't be able to get access and enough torque to the jubilee clips. You will struggle to find a decent large bladed screwdriver. Having finally removed the clips and repaired your knuckles with the last of the Elastoplast the hose will be frozen in place ( it's been there nearly 20 years already! ) so you boil several kettles and try to pry it off with a screwdriver. The hose will split and will need replacing as there is no slack to make up the difference. On top of that you will pick up a particularly nasty case of the runs after getting a tiny amount of the pipes contents on you when it finally lets go. You will try to unscrew the valve body and the through hull will instantly turn in it's seat. You call in a mate and get him to try to hold the fitting from outside and quickly discover that if the key is made thin enough to fit in the slots in the through hull flange ( that took 30 minutes to clear of years of accumulated antifoul ) then it is too thin to resist the torque required to crack the valve body loose. You will also discover that trying to communicate with your apprentice through a mere 8mm of hull layup requires yelling at the top of your voice or relaying commands via SWMBO in the companionway. Cue a sore throat. There won't be enough room to swing a large enough pipe wrench or spanner, cue more Elastoplast. At this point you are left with the option of cutting through the hull fitting, silver soldering a tommy bar to the flange or grinding off the flange. Either way you will end up with having to replace the through hull so you toddle off to find a replacement. Chances are the local supplier has only too big, too small or an imperial thread to your metric. A week later the replacement fitting will arrive, the retaining nut however will be absent ( or was shipped with CityLink and is now in parcel limbo land ) 2 days later and 130 miles of driving in foul weather and you will have fitting, a nut and sikaflex at the ready. Your apprentice will be curiously absent having taken up something more relaxing, like skydiving or mountaineering. You'll find a new helper, explain the relayed communications process and install the new through hull. Repairing the gouge in the hull where the helper slipped with the key tool and skidded across the glass will only take a day ( the chandler will only have a contrasting colour of antifoul however and the patch will haunt you until the next full antifoul job ). Bedding the new nut onto the inside of the fitting will go reasonably quickly once you exchange it for the correct size. Replacing the valve, a new one as disassembling the old fitting damaged the nut on the old one, goes smoothly right up to the point where the through hull rotates through a full turn and breaks the seal integrity. You disassemble and rebed the fitting and remember to get SWMBO to relay the message to the helper to hold tight this time. No amount of practice will prepare you for the dexterity required to apply PTFE thread sealing tape to a inch long piece of sharp edged pipe sticking up through your hull, more Elastoplast! You spend an afternoon cleaning up the grinding mess and then regell the entire area. You then notice that you have installed the valve backwards and the handle won't open the valve. Strip and rebuild ( including rebedding the through hull YET AGAIN ). The hose you bought to replace the original will prove to be impossible to slip over the hosetail fitting but you persevere and 20 kettles later you have the whole lot back together. Replace the jubilee clips ( more elastoplast ) and you are finally ready to relaunch.
I've worked on boats a bit!
The real fitting is the through hull fitting itself. It comes through the hull from outside and will be bedded into the hull with sikaflex or something similar. It may even be a tight enough fit to have been threaded in to the glass layup. That nut is probably doing very little at this stage anyway, it would have held the through hull in place, nice and square to the hull, while the sealing agent cured. Chances are its actually an ABS or similar high density plastic nut rather than a bronze one. ( which is why it broke in the first place ) 5'll get you 10 that it's been that way since the boat was delivered from the factory.
If you've ever tried to remove through hull fittings from a 'nearly mangy old plastic boat' you'd have a lot of faith in the strength of that fitting!
Even if the hull fitting was clobbered from outside it isn't going to pop into the boat, if the seal was broken it would just leak a bit and could be patched temporarily with a suitable sealing agent.
Replace the nut next time you haul if it bothers you. Take off the hose, unscrew the valve ( may need a key to hold the through hull from outside aided by a suitably large apprentice ), break the gelcoat away from the existing nut with an old chisel, unscrew the nut, clean up the surrounds, screw on a new nut bedding it on a small bead of sika. Re gelcoat and re-assemble, an hour or twos work.
What will actually happen .....
You won't be able to get access and enough torque to the jubilee clips. You will struggle to find a decent large bladed screwdriver. Having finally removed the clips and repaired your knuckles with the last of the Elastoplast the hose will be frozen in place ( it's been there nearly 20 years already! ) so you boil several kettles and try to pry it off with a screwdriver. The hose will split and will need replacing as there is no slack to make up the difference. On top of that you will pick up a particularly nasty case of the runs after getting a tiny amount of the pipes contents on you when it finally lets go. You will try to unscrew the valve body and the through hull will instantly turn in it's seat. You call in a mate and get him to try to hold the fitting from outside and quickly discover that if the key is made thin enough to fit in the slots in the through hull flange ( that took 30 minutes to clear of years of accumulated antifoul ) then it is too thin to resist the torque required to crack the valve body loose. You will also discover that trying to communicate with your apprentice through a mere 8mm of hull layup requires yelling at the top of your voice or relaying commands via SWMBO in the companionway. Cue a sore throat. There won't be enough room to swing a large enough pipe wrench or spanner, cue more Elastoplast. At this point you are left with the option of cutting through the hull fitting, silver soldering a tommy bar to the flange or grinding off the flange. Either way you will end up with having to replace the through hull so you toddle off to find a replacement. Chances are the local supplier has only too big, too small or an imperial thread to your metric. A week later the replacement fitting will arrive, the retaining nut however will be absent ( or was shipped with CityLink and is now in parcel limbo land ) 2 days later and 130 miles of driving in foul weather and you will have fitting, a nut and sikaflex at the ready. Your apprentice will be curiously absent having taken up something more relaxing, like skydiving or mountaineering. You'll find a new helper, explain the relayed communications process and install the new through hull. Repairing the gouge in the hull where the helper slipped with the key tool and skidded across the glass will only take a day ( the chandler will only have a contrasting colour of antifoul however and the patch will haunt you until the next full antifoul job ). Bedding the new nut onto the inside of the fitting will go reasonably quickly once you exchange it for the correct size. Replacing the valve, a new one as disassembling the old fitting damaged the nut on the old one, goes smoothly right up to the point where the through hull rotates through a full turn and breaks the seal integrity. You disassemble and rebed the fitting and remember to get SWMBO to relay the message to the helper to hold tight this time. No amount of practice will prepare you for the dexterity required to apply PTFE thread sealing tape to a inch long piece of sharp edged pipe sticking up through your hull, more Elastoplast! You spend an afternoon cleaning up the grinding mess and then regell the entire area. You then notice that you have installed the valve backwards and the handle won't open the valve. Strip and rebuild ( including rebedding the through hull YET AGAIN ). The hose you bought to replace the original will prove to be impossible to slip over the hosetail fitting but you persevere and 20 kettles later you have the whole lot back together. Replace the jubilee clips ( more elastoplast ) and you are finally ready to relaunch.
I've worked on boats a bit! nikc
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nigelmercier
RIP
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Brilliant!
30boat
N/A
Brush the area clean with a hard steel brush to expose fresh metal and remove any loose flowcoat.If the metal is corroded or dezincified it'll be imediately obvious.As suggested replace the skin fitting with a DZR one from ASAP.
danielefua
Well-Known Member
This is exactly what I would be afraid of if that little bit of rust is just the external visible sign of something more severe...
Anyone here can rule out this possibility with a 100% confidence? Sorry but I do believe that suggesting that everything is ok without a thorough examination is irresponsible! (I am not addressing vyv_cox, of course...)
Daniel
Heckler
Well-Known Member
Where pray does the rust come from?
S
Heckler
Well-Known Member
You know what, 2 years ago we had a spat, I made a new years resolution not to joust with you. I am finding it difficult not to.
I will bet a tenner that there is f all wrong with it, if I am wrong then I will pay it to the RNLI!
S
VicS
Well-Known Member
Maybe there is, maybe there isn't. Opinion is based on a poor photo and divided
Only sensible action is to check.
Heckler
Well-Known Member
For what its worth, Ive just changed an original thru hull in my Bene. It was 15 years old, no CR mark on it. Typical AWB fitting. The previous had stainless hose clamped a copper wire to the thread. There was a bit of pink on the thread. I got a new one from Asap. The big issue was getting the clamp nut undone. The thread was too long to get a socket on it and was recessed in between the inner liner and the hull. I ended up using my Dremel to cut thru the thread so that I could get the socket on. Interestingly the metal thickness was spot on and the pink was just on the surface. The fitting was well glued in by white stuff. Bottom line, the fitting was good! The valve however, it still worked and sealed but was stiff, was shagged. The chrome on the ball had gone. The reason for the stiffness.I positioned my camera around the back of a through hull fitting (which I can't physically see the back of) and took this photo - see the circled area. Should I panic?
If you do go down the route of changing, and I would certainly have a better inspection first, I think its OK, then get yourself a box spanner to tighten the nut before you start.
S
sarabande
Well-Known Member
I remain unconvinced by the general approach to this problem - that is leaving it until
1 it goes wrong
2 the next time the boat is out
3 the twelfth of never
That flange nut is a plastic one. Here is a proper brass one
View attachment 48070
If we assume that the external part of the through hull is of the same material as the tail (a dodgy assumption unless the OP knows for sure) then the flange nut is performing two functions:-
1 acting as a second line of defence against water by-passing the external fitting, and ingressing via the hole or the thread
2 squeezing down the sealant used at the original installation into the hole and around the tail thread.
It seems pretty clear (pending more pics) that at least one-sixth of the flange nut has failed in the past for some reason. When the failure took place is not clear, but it does not look a recent breakage as it appears to be covered by clean paint or other covering.
I would not be happy with losing 16% of the structural function of that flange nut, particularly as nylon (if that is the material) does have a finite service life, and we have all experienced hardening / embrittlement of other plastics.
Whilst it is not a mission critical issue (the absence of weap is mildly re-assuring) the picture should be treated as evidence that an element of failure in the integrity of the fitting is taking place.
OP might be happy doing a quick day sail in benign conditions, but a longer sail, or an object hitting the external part of the fitting, or a lift out strop applying torsional or shear stress, resulting in other parts of the flange nut breaking off, moves the risks higher up the scale.
Mitigation is additional pics of better definition; scratching away the paint/cover from around the other facets of the nut to reveal the base naterial and other info; and finally , the only 100% sure way - replacement.
1 it goes wrong
2 the next time the boat is out
3 the twelfth of never
That flange nut is a plastic one. Here is a proper brass one
View attachment 48070
If we assume that the external part of the through hull is of the same material as the tail (a dodgy assumption unless the OP knows for sure) then the flange nut is performing two functions:-
1 acting as a second line of defence against water by-passing the external fitting, and ingressing via the hole or the thread
2 squeezing down the sealant used at the original installation into the hole and around the tail thread.
It seems pretty clear (pending more pics) that at least one-sixth of the flange nut has failed in the past for some reason. When the failure took place is not clear, but it does not look a recent breakage as it appears to be covered by clean paint or other covering.
I would not be happy with losing 16% of the structural function of that flange nut, particularly as nylon (if that is the material) does have a finite service life, and we have all experienced hardening / embrittlement of other plastics.
Whilst it is not a mission critical issue (the absence of weap is mildly re-assuring) the picture should be treated as evidence that an element of failure in the integrity of the fitting is taking place.
OP might be happy doing a quick day sail in benign conditions, but a longer sail, or an object hitting the external part of the fitting, or a lift out strop applying torsional or shear stress, resulting in other parts of the flange nut breaking off, moves the risks higher up the scale.
Mitigation is additional pics of better definition; scratching away the paint/cover from around the other facets of the nut to reveal the base naterial and other info; and finally , the only 100% sure way - replacement.
Last edited:
Heckler
Well-Known Member
Hey Tim,
Im an old man with old man eyes! BUT I see a copper alloy nut, as you have pictured, covered with flo/gel coat with a bit of the coating chipped off! Look to the left of the red ring, you can just see the flange under the coating!
S
VicS
Well-Known Member
I am even older but maybe my eyesight is better. In the centre of that red ring I think I can see the thread of the skin fitting where I should not be able to see the thread, where I would not be able to see it if the back nut is intact.
As I said in post #2 possibly an illusion. A better picture or physical examination should confirm or otherwise
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Tradewinds
Well-Known Member
If you can't see it directly how about getting something like this (maybe smaller?)
http://www.amazon.co.uk/Rolson-6051...qid=1419975876&sr=8-16&keywords=dental+mirror
http://www.amazon.co.uk/Rolson-6051...qid=1419975876&sr=8-16&keywords=dental+mirror
