Halo
Well-Known Member
I am replacing my skin fittings and the new ones have an attachment to secure an earth/anode strap onto the backing washer. I have always attached my dzr fittings to an anode but does it make sense to do so on 316 ?
Stainless skin fitting Earth
- Thread starter Halo
- Start date
rogerthebodger
Well-Known Member
If your boat is GRP and the skin fitting is isolated from all others IMHO there is no need to connect the skin fittings to anything else
Do ensure the fitting and the thread is completely sealed to prevent any water getting into the thread cavities to reduce the possibility of crevice corrosion
I have all 316 skin fittings on my steel boat and I went to great details to isolate the fitting from the steel hull and from each other
Do ensure the fitting and the thread is completely sealed to prevent any water getting into the thread cavities to reduce the possibility of crevice corrosion
I have all 316 skin fittings on my steel boat and I went to great details to isolate the fitting from the steel hull and from each other
Pye_End
Well-Known Member
VicS
Well-Known Member
No
It is recommended these days that skin fittings should be made of a corrosion resistant material and not bonded to each other or to anodes. (That includes DZR.)
As Rogershaw says ensure that they are well sealed in.
Also seal the thread well between them and the seacock valves Loctite 577 thread sealant might be appropriate here as it will lock the valve in position as well as sealing the threads. It is said to be particularly suitable for stainless steel. Loctite 577 Thread Sealant - 50ml
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Halo
Well-Known Member
I have a tube of sikaflex ready for the job. Do you think loctite 577 is a significantly better option versus this or PTFE tape for the threads ??
geem
Well-Known Member
The problem with bonding skin fittings on a grp boat is that if for what ever reason you lose the connection to the anode, you are left with all your skin fittings in a circuit that might then start to corrode. If the skin fittings are not bonded then they are not in a circuit.
Some of my bronze skin fittings are 40 years old. Have never been protected by anodes and are perfect.
Some of my bronze skin fittings are 40 years old. Have never been protected by anodes and are perfect.
rogerthebodger
Well-Known Member
I in fact used Sikaflex to seal both the skin fitting into the hull and the fittings onto the threads.
I also fitted a TEE on top of the ball valve so if necessary I could remove the plug in the top of the tee then open the ball valve to rod through the ball valve/skin fitting. The inlet/outlet is attached to the side entry of the tee.
Halo
Well-Known Member
Nice idea !
VicS
Well-Known Member
Sikaflex is a popular choice . I suggest a Loctite thread sealer and thread locker as an alternative
The trouble with ptfe tape is that it does not fix the orientation of the valve. and is really only suitable for tapered threads
A back nut is a good way of fixing the valve orientation but maybe not in conjunction with tape
rogerthebodger
Well-Known Member
No disrespect to Vic but I prefer to fix the orientation of the tee and the ball valve by trimming the end of the tee with a file so the tee is locked in place by the tee and skin fitting locking face to face. The thread is sealed with sikaflex to ensure the fully sealed thread.
I also use 3 piece ball valves that can be orientation by taking the ball valve apart. It also allow servicing without disturbing any piping work.
The plugs on the top of the tee have been changed to a face seal plug with a plastic face seal. Easer to inspect and reseal the plug.
I also use 3 piece ball valves that can be orientation by taking the ball valve apart. It also allow servicing without disturbing any piping work.
The plugs on the top of the tee have been changed to a face seal plug with a plastic face seal. Easer to inspect and reseal the plug.
[70521]
Well-Known Member
I prefer PTFE tape. There is a lot of rubbish "misspoken" about it not being able to line up a valve and it been unsuitable for tapered threads.
VicS
Well-Known Member
It is suitable for tapered threads. Its good for tapered threads
Its not so good for parallel threads , which ideally should tighten on to a joint washer .