Halo
Well-Known Member
I am also thinking of fitting composite skin fittings and seacocks this winter. One thing really attracting me to them is that I can ditch the ugly great zinc anode from under the valve cluster !
Marelon Sea Cocks / Valves
- Thread starter Blue5
- Start date
prv
Well-Known Member
Do you actually need the anode at the moment? No anode attached to any of my skin fittings, no problem in 20 years.
Pete
Daydream believer
Well-Known Member
Sorry to contradict some pf the posts above
DZR does breakdown on GRP
The Hanse Owners forum has a long thread on the matter
In addition the valves & fittings breakdown
This seems to be particularly prevalent when there is items like electric toilets & the valves etc disintegrate on the foul water outlets
I posted a picture of a DZR fitting above the valve that just fell apart in my hand after 8 years on the Hanse owners forum
If you are interested it is in "chit chat" under seacocks
DZR does breakdown on GRP
The Hanse Owners forum has a long thread on the matter
In addition the valves & fittings breakdown
This seems to be particularly prevalent when there is items like electric toilets & the valves etc disintegrate on the foul water outlets
I posted a picture of a DZR fitting above the valve that just fell apart in my hand after 8 years on the Hanse owners forum
If you are interested it is in "chit chat" under seacocks
Halo
Well-Known Member
Hi Jerry
I had a look at the Truedesign website. The product looks good but I dont like the flow restrictions in the valves - the 1/2", 3/4" and 1" all have the same aperture of 19mm and the 1 1/4" and 1 1/2" valves have a 32mm aperture. I could be gettting rid of the corrosion problems but getting blockages.
Do you concur?
Martin
Sans Bateau
Well-Known Member
Thats rather curious. A friend had a Hanse 371 which he sold a few years ago, he had all sorts of electrolysis problems and could never find out why. I dont know about the seacocks though. Is this a Hanse problem?????
Tranona
Well-Known Member
Difficult to comment without seeing the full details, but just a couple of observations. Firstly many builders have been using fittings and valves that are not DZR - that is what the main controversy is about. Secondly, brass (as opposed to DZR) can suffer from dezincification on its own irrespective of what the hull material is. However this is not connected directly to electrolysis as most commonly found where components made of dissimilar metals are in electrical contact with eachother, such as a shaft and a prop, or a bronze fitting in a steel hull. A bronze or DZR skin fitting and valve in a GRP hull is not in contact with other metals so does not suffer from electrolysis and therefore does not need an anode.
So the failure of your valve is either because it was inferior material or was connected to something else - not just because it was in a GRP hull.
Blue5
Well-Known Member
The more I look into this the more confused I get................
If I look at DZR valves, what material does the through hulls, bends and hose tails need to be.
If I look at DZR valves, what material does the through hulls, bends and hose tails need to be.
Halo
Well-Known Member
The picture - of a skin fitting I removed last winter says it all as you an see the de-zinced section - after 5 years in water
prv
Well-Known Member
I thought electrolysis and dezincification were separate things? Though I admit I'm no expert.
What were those skin fittings made of?
Pete
KellysEye
Well-Known Member
>Quite clear to me, in the pictures. A 45 degree bend between the hull and the valve, then the hose comes straight off the valve.
Ah yes, I can see that now, thanks.
Ah yes, I can see that now, thanks.
Tranona
Well-Known Member
Skin fittings are usually bronze and the valves DZR or bronze, hose tails bronze or DZR. You can get them from ASAP mail order and they clearly state what the material is. Typically DZR is twice the price of brass, so if they are "cheap" then almost certainly inferior.
Halo
Well-Known Member
Pete
I think the fittings were/are DZR brass (but not sure to be honest) which is another reason why I am changing the rest.
I believe that electrolysis is the process which drives de-zincification. The zinc part of the alloy dissolves away leaving the copper part. The copper is darker than the zinc (which is grey) so that is why there is a dark ring on the inside of the fitting in my picture. The remaining copper is much weaker and looks different.
Bronze is better than brass because it does not have much (if any) zinc in it.
Whenever there are different metals together in salt water a similar process attacks one of the metals.
Zinc anodes are used as a sacrifice to be sure that the important metal parts are proteced from electrolysis but need to be connected eletcrically with the zinc anode in the sea water
That is my laymans understanding of what happens and I hope it helps
Martin
Plevier
Well-Known Member
I eventually found your post - a link would have been helpful! - but the picture is not visible.
How do you know your fitting was DZR not plain brass please? A lot of the thread - not read it all - seems to think Hanse used brass not DZR.
Did it have the CR mark on it?
Tranona
Well-Known Member
Not quite correct as you will see from the post above. Your skin fitting looks like plain cheap brass which is prone to dezincification in salt water. That would not happen with DZR - as its name implies it is dezincification resistant. It could still, however happen if the fitting was connected electrically to a dissimilar metal, in which case an anode may be required linked to both.
This is not the case with skin fittings through GRP. They are not connected to anything, so do not need an anode and if DZR or bronze will not suffer from dezincification.
So suggest you replace them with the correct material and remove the anode, although if you have a conventional shaft drive you may well benefit from an anode bonded to the shaft.
prv
Well-Known Member
...except where people start wiring them up to batteries and mains earths and things like that.
Pete
Daydream believer
Well-Known Member
Troubador
Hanse say they fit DZR
My fitting just collapsed in my hand and any reference. Would have been unreadable
The new DZR fittings had no marking & the chandlery had brass, DZR & bronze all next to each other on the same shelf. I only have the managers word that I have DZR as I have no idea if the fittings could have got mixed up
Another contributor to this thread says skin fittings are Bronze. Unfortunately that is misleading. It has been recorded in the Hanse forum that other manufacturers do not necessarily fit bronze. The EU rules -according to extensive reporting by Yachting Monthly is that the fittings used have to last 5 years.
I suggest anyone concerned about this subject read the YM article as this does seem to be more informative with fact rather than fiction or opinion
Hanse say they fit DZR
My fitting just collapsed in my hand and any reference. Would have been unreadable
The new DZR fittings had no marking & the chandlery had brass, DZR & bronze all next to each other on the same shelf. I only have the managers word that I have DZR as I have no idea if the fittings could have got mixed up
Another contributor to this thread says skin fittings are Bronze. Unfortunately that is misleading. It has been recorded in the Hanse forum that other manufacturers do not necessarily fit bronze. The EU rules -according to extensive reporting by Yachting Monthly is that the fittings used have to last 5 years.
I suggest anyone concerned about this subject read the YM article as this does seem to be more informative with fact rather than fiction or opinion
Tranona
Well-Known Member
However, even if you do that, and read Vyv Coxs additional articles on the subject you will still be confused as to what builders actually fit. This is because they either won't say or more likely don't always know.
On the other hand, if you are replacing valves and fittings yourself you now will have better control over what you fit. Since the articles, sellers (particularly the big distributors) have been much clearer about labeling and describing their stock. The ASAP site I referred to above very clearly shows the material for each fitting so you can buy with confidence.
DZR and bronze are widely available and as many have said here are not prone to failure through corrosion if used in GRP hulls and are not connected electrically to anything else.
Daydream believer
Well-Known Member
I agree all you say except the last paragraph
Hanse say they fit DZR yet I & others have had some failures
It has to be accepted that Hanse are telling the truth
One further has to consider outside influences. Ie what electrical currents are being generated by surrounding influences. My unit is not connected electrically to anything
Hanse say they fit DZR yet I & others have had some failures
It has to be accepted that Hanse are telling the truth
One further has to consider outside influences. Ie what electrical currents are being generated by surrounding influences. My unit is not connected electrically to anything
Plevier
Well-Known Member
OK so it's not provable either way. However my guess is that your failed fitting was brass, and personally I would not accept a new fitting as being DZR unless it was marked with DZR or CR or a known good metal spec number.
Yes I have read the YM article and much else including Vyv Coxs excellent website.
PS the spec sheet for my 2003 Jeanneau claims the fittings are Bronze. Unfortunately I don't think that's true either.
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Sans Bateau
Well-Known Member
Agreed, it a very good site and the pricing is as good as it gets. Last year I replaced all my skim fittings, valves and tails with DZR from ASAP.
A chandler where everything is lose on the shelf, and nothing marked? Walk away. DZR is marked, but I cannot remember with what I think it should be CR but the C and the R as one graphic.