CaptainBob
Well-Known Member
I'm going to be putting a blanking cap on an un-used skin fitting shortly.
How do I best seal the blanking cap when I screw it on?
How do I best seal the blanking cap when I screw it on?
PTFE plumbers tape on skin-fitting thread?
- Thread starter CaptainBob
- Start date
VicS
Well-Known Member
It depends on whether or not it is a tapered thread.
If it is PTFE tap will work nicely and will always be easy to undo again, alternatively any pipe jointing compound. I guess Sikaflex will do nicely as well but it may make it difficult to undo in the future.
If they are parallel threads with flat joint faces coming together then a joint washer is really called for but I guess a good lashing of Sikaflex will seal it up.
If it is PTFE tap will work nicely and will always be easy to undo again, alternatively any pipe jointing compound. I guess Sikaflex will do nicely as well but it may make it difficult to undo in the future.
If they are parallel threads with flat joint faces coming together then a joint washer is really called for but I guess a good lashing of Sikaflex will seal it up.
Talulah
Well-Known Member
It depends what I had around without having to go and buy something else. If I was doing it I would just use boss white or equivalent. I keep some in my tool bag and it's cheap.
wotayottie
Well-Known Member
unless it was for a short term, I would take out the skin fitting and laminate over the hole. Otherwise its a problem waiting to happen because it will get forgotten.
pete
Well-Known Member
Use PTFE sparingly on the thread but put a fibre washer in the cap so as when it bottoms out as it will on a parallel thread it will compress the washer.
Pete
Pete
ShipsWoofy
Well-Known Member
Don't waste your energy. The Cap'n has already been given this advice after the skin fitting rotated and he asked (great resource PBO) what to do.
I agree, a blanked off skin fitting under the water-line that has no purpose is a cowboy solution, but it sadly appears that Bob is not listening.
So my advice, put a cork in the pipe, that should do it, yup, maybe if you can't find a cork a bit of rag and some bodge tape.
Also
Make sure you fit some good water pumps.
I agree, a blanked off skin fitting under the water-line that has no purpose is a cowboy solution, but it sadly appears that Bob is not listening.
So my advice, put a cork in the pipe, that should do it, yup, maybe if you can't find a cork a bit of rag and some bodge tape.
Also
Make sure you fit some good water pumps.
VicS
Well-Known Member
[ QUOTE ]
Don't waste your energy. The Cap'n has already been given this advice
[/ QUOTE ] In fairness to the man he does accept that glassing in the hole is the best way forward, gave his reasons for blanking off the fitting for now and indicated his intention to glass in the hole at the next oppotunity.
He said [ QUOTE ]
I appreciate the thought that re-glassing it is the best way forward - but it's bloomin chilly here now, and will be right up to the point that I go back in the water.... also I've never done ANY glassing, I have no power available at the boat, and a blanking cap is gonna cost me £3.48GBP... so I think it's gonna be a sikaflex and blanking plate job for the moment.
Many thanks for the detailed glassing post olewill!! I'll print that and keep it for next lift out.
[/ QUOTE ]
Don't waste your energy. The Cap'n has already been given this advice
[/ QUOTE ] In fairness to the man he does accept that glassing in the hole is the best way forward, gave his reasons for blanking off the fitting for now and indicated his intention to glass in the hole at the next oppotunity.
He said [ QUOTE ]
I appreciate the thought that re-glassing it is the best way forward - but it's bloomin chilly here now, and will be right up to the point that I go back in the water.... also I've never done ANY glassing, I have no power available at the boat, and a blanking cap is gonna cost me £3.48GBP... so I think it's gonna be a sikaflex and blanking plate job for the moment.
Many thanks for the detailed glassing post olewill!! I'll print that and keep it for next lift out.
[/ QUOTE ]
ShipsWoofy
Well-Known Member
Ok, fair point, and £3.48 is a lot cheaper than getting a man in...
Not so cheap if the fitting fails, again.
I hate the skin fittings I have to have, the idea of having fittings that have no purpose is ludicrous in my opinion. Advice to use a blanking plug is poor.
Get a genny from a hire shop with a decent heater and bobs ya uncle. A couple of hundred quid to do the job properly now might save more than a fortune in the future.
I guess I am just amazed that he has chosen this as the way forward, I suppose that is why we use surveyors when buying a boat.
Not so cheap if the fitting fails, again.
I hate the skin fittings I have to have, the idea of having fittings that have no purpose is ludicrous in my opinion. Advice to use a blanking plug is poor.
Get a genny from a hire shop with a decent heater and bobs ya uncle. A couple of hundred quid to do the job properly now might save more than a fortune in the future.
I guess I am just amazed that he has chosen this as the way forward, I suppose that is why we use surveyors when buying a boat.
CaptainBob
Well-Known Member
Blimey! A serious flaming! Hehe /forums/images/graemlins/tongue.gif
Cheers for sticking up for me VicS
DW - I really wouldn't be confident enough to undertake a job like this on my own at this stage. I've JUST bought this boat, it's my first boat, and I have zero glassing experience. I have no idea what materials to use, tools to use, or how much heat to use.... so my realistic options are:
1. £3.48 + a tube of Sikaflex (and possibly plumbers tape?).
2. £100 x ? Pay a boatyard to sort it for me.
Considering that I'm skint after the purchase of the boat, I'm left with little choice here.
Oh, there's another option - don't put the boat in the water until spring 2009.
Nah, d'ya know what, I'm gonna do a damn good job on this blanking off thing, enjoy 2008, and get either the knowledge or the funds sorted for 2008/2009 layup period.
--
So have only cowboys ever actually used these blanking plate thingys? I wonder why they still make them. Encourages bad behaviour I reckon! /forums/images/graemlins/confused.gif /forums/images/graemlins/tongue.gif
Cheers for sticking up for me VicS
DW - I really wouldn't be confident enough to undertake a job like this on my own at this stage. I've JUST bought this boat, it's my first boat, and I have zero glassing experience. I have no idea what materials to use, tools to use, or how much heat to use.... so my realistic options are:
1. £3.48 + a tube of Sikaflex (and possibly plumbers tape?).
2. £100 x ? Pay a boatyard to sort it for me.
Considering that I'm skint after the purchase of the boat, I'm left with little choice here.
Oh, there's another option - don't put the boat in the water until spring 2009.
Nah, d'ya know what, I'm gonna do a damn good job on this blanking off thing, enjoy 2008, and get either the knowledge or the funds sorted for 2008/2009 layup period.
--
So have only cowboys ever actually used these blanking plate thingys? I wonder why they still make them. Encourages bad behaviour I reckon! /forums/images/graemlins/confused.gif /forums/images/graemlins/tongue.gif
PCUK
Well-Known Member
Is there a sea-cock on the fitting?
CaptainBob
Well-Known Member
There was. A seized one. Not used.
I removed it so I could replace it with a blanking plate - hence this and the other thread.
Why do you ask?
I removed it so I could replace it with a blanking plate - hence this and the other thread.
Why do you ask?
ShipsWoofy
Well-Known Member
ok, sorry about the flaming.
It is not because of any malice, I just can't sit back and watch you bodge a job in such a serious area. I am all for getting away with a self tapper to fix a bracket when you should really use a nut and bolt.
But what you are doing is under the water line, a fitting that has already failed.
Being broke is a state of life when you have a boat, I am in no position to throw money at anything. But, this is a structural repair, if this fails, well, the consequences may be dire or will stop all future pleasure of the boat.
If, lets say the worst happens and she sinks on the mooring, I would be amazed if the insurance would pay up when they find out why. That will mean a wrecked boat, engine etc. You will have to fork out the costs of wreck removal (seriously not cheap!). OK this is worst case scenario, but ..
Then there is the case of the fitting failing 5 miles off, I wonder what would go through your mind and would the saving be worth it then.
I don't know where you are, if close enough I would come and help you carry out the repair for no cost other than materials, this is how passionate I am about doing this particular job correctly.
It is not because of any malice, I just can't sit back and watch you bodge a job in such a serious area. I am all for getting away with a self tapper to fix a bracket when you should really use a nut and bolt.
But what you are doing is under the water line, a fitting that has already failed.
Being broke is a state of life when you have a boat, I am in no position to throw money at anything. But, this is a structural repair, if this fails, well, the consequences may be dire or will stop all future pleasure of the boat.
If, lets say the worst happens and she sinks on the mooring, I would be amazed if the insurance would pay up when they find out why. That will mean a wrecked boat, engine etc. You will have to fork out the costs of wreck removal (seriously not cheap!). OK this is worst case scenario, but ..
Then there is the case of the fitting failing 5 miles off, I wonder what would go through your mind and would the saving be worth it then.
I don't know where you are, if close enough I would come and help you carry out the repair for no cost other than materials, this is how passionate I am about doing this particular job correctly.
CaptainBob
Well-Known Member
Wow! Cheers for the offer!
But are we at crossed purposes here though?
All boats (well. a lot) have skin fittings... I'm just gonna blank one off... if this one is such a major deal, what about all the others that _have_ to be there? And what about the impeller, and the depth sounder transducer?
I fully intend to properly re-seat the existing fitting first. Then blank it off.
Am I missing something?
But are we at crossed purposes here though?
All boats (well. a lot) have skin fittings... I'm just gonna blank one off... if this one is such a major deal, what about all the others that _have_ to be there? And what about the impeller, and the depth sounder transducer?
I fully intend to properly re-seat the existing fitting first. Then blank it off.
Am I missing something?
VicS
Well-Known Member
[ QUOTE ]
But what you are doing is under the water line, a fitting that has already failed
[/ QUOTE ] I'm sticking with the Captain on this. He has removed a defective seacock (I guess he means gate valve) and his assessment is that the skin fitting is still sound. He said no "sign of corrosion" and he has been told about dezincification being a possibility with brass fittings.
I dont think you have not said what fitting it was Bob. If it was one of Westerly's originals then it is probably bronze .
If it was not redundant he and most others would have screwed on a new valve and that would have been that. It would have continued in use!
But what you are doing is under the water line, a fitting that has already failed
[/ QUOTE ] I'm sticking with the Captain on this. He has removed a defective seacock (I guess he means gate valve) and his assessment is that the skin fitting is still sound. He said no "sign of corrosion" and he has been told about dezincification being a possibility with brass fittings.
I dont think you have not said what fitting it was Bob. If it was one of Westerly's originals then it is probably bronze .
If it was not redundant he and most others would have screwed on a new valve and that would have been that. It would have continued in use!
Gunfleet
Well-Known Member
If you've ever seen water come through a one inch hole in a boat, you'd wish you'd gone with DW. Take the log impellor out and see how long you can watch the water pour through. Now imagine you are out of sight of land...
How many fire extinguishers do you carry? That's the other useless expensive stuff on a boat. And flares. Two vhfs? Wearing a bloody life jacket all the time... that's a pain in the arse. I think I'll lay off lifejackets this season.
How many fire extinguishers do you carry? That's the other useless expensive stuff on a boat. And flares. Two vhfs? Wearing a bloody life jacket all the time... that's a pain in the arse. I think I'll lay off lifejackets this season.
poter
Well-Known Member
Yup I think you are missing a trick ... Doggy's point is valid in that any thru hull fitting below the waterline should be taken very seriously.
In my view (& I assume that your Yacht is out of the water) If you have one suspect thru hull fitting, I would replace the lot including all the sea cocks. The one that you are currently having problems with should be removed & glassed over. If you have a problem with glassing, there will be someone in your boatyard/marina with the skills - ask around.
Do get bronze thru hull fittings & if you can find, bronze sea cocks as well. It will be a little late when you are jumping into your life raft thinking that you should have replaced the skin/seacock fitting at the time.
poter
In my view (& I assume that your Yacht is out of the water) If you have one suspect thru hull fitting, I would replace the lot including all the sea cocks. The one that you are currently having problems with should be removed & glassed over. If you have a problem with glassing, there will be someone in your boatyard/marina with the skills - ask around.
Do get bronze thru hull fittings & if you can find, bronze sea cocks as well. It will be a little late when you are jumping into your life raft thinking that you should have replaced the skin/seacock fitting at the time.
poter
VicS
Well-Known Member
[ QUOTE ]
Wow! Cheers for the offer
[/ QUOTE ] I addition to the advice William H has offered on grp repairs you might find THIS useful. It is a bit dated but if there is anything there of relevance then you can thank the forumite (a well known one! ) who has put it on his website.
You might even find the rest of the website interesting
Wow! Cheers for the offer
[/ QUOTE ] I addition to the advice William H has offered on grp repairs you might find THIS useful. It is a bit dated but if there is anything there of relevance then you can thank the forumite (a well known one! ) who has put it on his website.
You might even find the rest of the website interesting
CaptainBob
Well-Known Member
Ah OK. I see the misunderstanding now.
There is NOTHING wrong with my skin fitting at all. I accidentally undid the nut that holds it in place a little, and in doing so unstuck the existing sikaflex bonding.
I'm going to remove the skin fitting. Clean it all up. Re-seat it on fresh sikaflex. Screw on a blanking cap.
There is NOTHING wrong with my skin fitting at all. I accidentally undid the nut that holds it in place a little, and in doing so unstuck the existing sikaflex bonding.
I'm going to remove the skin fitting. Clean it all up. Re-seat it on fresh sikaflex. Screw on a blanking cap.
PaulJS
Well-Known Member
As a professional Marine Engineer, I can't really see a problem with fitting a blank, provided of course that the original fitting is sound. Logically, a blank is safer than the original valve as it has fewer points of potential failure. However, if the line is totally redundant, got to agree that it would be better to remove and glass over when the Cap'n has the time and finances to do the job properly.
Got to be a good idea to mark a tell-tale on the blank so that it can be monitored to ensure it isn't loosening, also, check function of bilge alarms and pumps regularly!
Got to be a good idea to mark a tell-tale on the blank so that it can be monitored to ensure it isn't loosening, also, check function of bilge alarms and pumps regularly!
PaulJS
Well-Known Member
Aaargh, sorry, my security program got in the way of my last post, thread tape in moderation is suitable on a taper thread as it's job is to lubricate the threads enough to allow the fitting to be sufficiently tightened for the threads themselves to conform to each other thus forming a metal to metal seal. However if it's a parallel thread, use a sealing washer to make the seal, and I would recommend a smear of thread locking compound.
