Anode bolts

dur

dur

Well-Known Member
Joined
19 May 2003
Messages
420
Location
Chichester
www.gaff-rig.co.uk
New anode time. Is there any reason I shouldn't use ordinary bzp set screws instead of the studs with the square washer welded on part way up, which are sold at enormous expense by the swindleries? It upsets me to pay £ 8.00 for something that cost a few pennies.
 
They are only zinc plated I think you will find. It would not say much for the anodes if the fixings only lasted for 5 minutes. The plating stops them rusting while out of the water.
 
Agree with Vic, they are not galv, just elecro zinc plated.

I can't see why not. You would have to cut the head of, us
e two penny washers between the plank, then another pair of nuts, one outside for the anode and one in for the terminals. Because the stud would spin, unlikje the square purpose made one, you will need an assistant to tighten it up. If you need terminals as well then the 'proper stud' starts to look a little more appealing.
Try a cheaper swindlery?

I'm sure you know this.....to reduce future de-lignification of the timber around the holes.....alkaline salts and all that, clean back the paint on both sides of the plank to timber, open up the hole by a mil or so, and apply two coats or more of epoxy, warming a little with a hot air gun. Repaint, and refit the stud witha little grommet of cotton and somne non setting mastic (not silicon sealant or sikaflex-all wrong).

One other tip.......once the anode is fitted ( on a greased thread), cut of the excess thread flush with the top of the nut. Why? when you next remove the nut it wont bind on the rusty exposed thread, and spin the stud.....meaning you have to change it AGAIN!!

I'm sure you know all this Max!!

I have just got a few studs in...I'll tell you what they should cost!
 
Thanks. I guess I had figured out most of this - I just kept thinking that I must be missing something! The old trick - make something expensive and a sucker like me thinks there must be something special about it despite what common sense is telling me!
I have some of that non setting mastic used for fitting old fashioned window frames - should be ok?
 
This may be helpful to all of us.
Farm suppliers do heavy Galvanised bolts some with square shanks and nuts, generally for hanging 5 bar Gates etc.
They may have to be modified a bit in a lathe.
The ones I am thinking of are 5/8" or 3/4" dia so may suite the larger boat.
They should have a stock of smaller sizes as well, of proper heavy Galvanised Bolts, Washers and Nuts.
Also they are good for mastics and many other items that can be useful on wooden boats.
Well worth a good rummage and look-see.
and Stockholm Tar products can be found in the horsey section, but they like boat swindlers can be expensive the horsey section that is. /forums/images/graemlins/grin.gif
Cheers David.
 
Isn't there more to this than your contributers have discussed .

The square washer has a specific function which could save your boat. If the underwater part of the bolt (or nut) corrodes right thru, this part stops the remaining bit of the bolt from coming into the boat leaving a nice 8mm or so hole open to the briny.

Believe me this can happen!

david
 
[ QUOTE ]
then another pair of nuts, PLUS one outside for the anode and one in for the terminals.
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Sorry, I have added the word 'plus'. One of course sandwiches the plank between two nuts and washers, then fits the anode, then the star washer, then another nut!! Thought that was obvious.

Its very unlikley that the stud would corrode away. Its protected by the anode. If you were to leave it so long that the anode fizzed away and left a stud, then it would take some time before that rotted away enough to sink the boat. If you had not noticed then you are "better of drowned". Of course you would not drown because you would find the leak and stick a bit of rag in the hole to get you home.

The trade price to me for MG Duff studs is £7.10 per pair, plus VAT.
 
I agree Nick. I can't see that the plate can be there in case the stud rots off. The stud is 8 or 10 mm and the plate is 2mm. I suspect the plate is there to make it easier to get a seal - possibly on thin hull skins. Wind Song is not particularly heavilly built but still has 7/8" plank which seems to be plenty for a bit of mastic to make a seal. I think I will just use a set screw through from the outside with penny washers against the planking with a lock nut on the inside plus another nut or two for the terminals. Unless someone can persuade me differently!
 
I have seen an anode bolt corroded right down to flush with the hull on a boat that had new anodes fitted that season. This was a very rare case but came about through no fault or negligance of the owner.
The next boat on the pontoon had a fault with its electrical system such that it was pumping a dc voltage down the mains earth cable. The faulty boat had an automatic charger so the owner did not notice the drain on his batteries. The marina electrics were in good condition, but as many of you will know modern electrical trips are designed to spot a difference between live and neutral rather than a small current flowing on the earth cable. If this had been a bolt instead of the correct fitting it might have failed completely, leading to the boat sinking.
If you are wondering about would a galvonic isolator have protected the innocent boat the answer is no. A galvonic isolator will only stop voltages less than about 1 volt. An isolating transformer would have saved the innocent boat however. You can imagine the condition of the outdrive!
Beware of leaving your boat permantely pluged into shore power.
 
Ah yes Alan, in a Marina environment all hell can break loose!

I would never risk:
Fitting a ring main to a wooden boat of personal or historical value.
Leave it plugged in for long periods
'Earth' anything to anything.
Connect seacocks, keel bolts etc up to an anode

If you really need mains, just pop a plug through a vent or port hole and plug in what you need. I would not trust a galvanic isolator even if it cost a mint!

The above opinions are based on seeing the effects of the above over the last 21 years.........

I have seen a new bronze folding prop become unservicable in 5 months due to the boat next door having a poor instalation......
 
One of many good reasons to avoid marinas I guess.
But are you saying that the stud rotted off flush with the 2mm thick plate leaving it intact? I am willing to be persuaded but I can't see why the plate would outlast the bolt and if it wouldn't then we are back to relying on the remainder of the bolt/stud staying in the hole.
 
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