Sealing Anode stud - silicone, sika, epoxy

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gregcope

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Hi

My anode stud moves and I had to remove it to take the nut off.

So now to replace what should i use to seal it on replaxement?

sika (or PU40)? Silicone? Epoxy?

Fancy sika as i do not want to replace it again. Nor do I want it to leak...

Also, apon inspection both grounding wires were damaged either along their length or at the crimp (insufficient support). Worth checking yours.
 
Worth looking at MG Duff's fitting instructions:- Anode fitting instructions

I see they only say "sealant" so its your choice . Puraflex PU40 is similar to Sikaflex and made by Everbuild, a Sika Company, but cheaper.

Some folks will recommend CT1. Stix-all is similar and made by Everbuild . Dont use ordinary builders silicone.

Are your using the "proper" studs with a welded on flange ?

Note MGDuff recommend 4mm² wire for the bonding

Note also the use of a backing pad ... often I suspect omitted
 
VicS said:
Worth looking at MG Duff's fitting instructions:- Anode fitting instructions

I see they only say "sealant" so its your choice . Puraflex PU40 is similar to Sikaflex and made by Everbuild, a Sika Company, but cheaper.

Some folks will recommend CT1. Stix-all is similar and made by Everbuild . Dont use ordinary builders silicone.

Are your using the "proper" studs with a welded on flange ?

Note MGDuff recommend 4mm² wire for the bonding

Note also the use of a backing pad ... often I suspect omitted
Click to expand...

yes stud has a welded flange, like a thick washer that is placed sea side of the hull.

There is no backing pad and is in a valley between “ribs” that is only 15cm or so wide. It did have a large penny washer, which i am reinforcing with an even larger one.
 
gregcope said:
My anode stud moves and I had to remove it to take the nut off.
Click to expand...

It helps to use two nuts to hold the anode on each stud. With a spanner holding the nut closest to the hull stationary, you can then undo the outside nut, which will remove any crud in the stud's threads as it comes off. The nut holding the anode on should then unscrew easily without disturbing the stud.
 
Oh. I thought there were two options;

If you want it to come off again; Silicone otherwise Sika (etc). I get the later is mich stronger.
 
gregcope said:
Oh. I thought there were two options;

If you want it to come off again; Silicone otherwise Sika (etc). I get the later is mich stronger.
Click to expand...
Unless they are quite special engineering versions, which involves accelerants and catalysts, silicone sealants have little strength and poor adhesion. Their worst feature for us is that they inhibit the curing of many other useful products such as sealants and paints.

On these forums you will sometimes come across of accounts of, e.g. Sikaflex remaining soft for months. This is almost certainly because silicone sealant has been used previously.

It is a myth that Sikaflex cannot be removed. I have detached fittings sealed with Sikaflex and/or Puraflex many times.
 
One friend vs. hundreds of thousands of very satisfied Sikaflex users?
I'm sure there are conditions where it will not seal as mentioned above but following the fairly simple process will always work. I.e. clean dry and no silicone etc. I understand it can't be used on acrylic windows but I don't have any so not something I have looked into.
It will sometimes stick too well if a fitting, portlight, hatch etc. needs to be removed again :) There is a solvent that will help here but I can't remember what is called and is available from Storrar chandlers in Newcastle
.
http://www.bluemoment.com/downloads/sikaflexusersguide.pdf
 
Stixall is what I used the last time we changed. No leaks, and no issues. I can't see it would be an issue removing, if the studs rotate again next time, they are easy to knock out with a hammer & drift.

It's a couple of anode studs, so any good adhesive sealant would be fine - it's not like they are likely to loosen up (assuming fitted correctly ;) ). Apart from that, as others have said - avoid silicone sealant
 
redmunduf said:
It depends on many factors. I would never use Sika. A friend of mine used it, and it didn't stick at all. It's like he didn't even glue it on. I've used silicon myself, but the one I used is not suitable for this purpose as far as I know. Water will harm it, and if you add constant vibration, sooner or later, the anode stud will fall off. But I read an article on https://sealwithease.com/what-is-the-best-sealer-for-butcher-block-countertops/ about epoxy resin. It seems to me that it would work best. It has excellent properties.
Click to expand...
Sorry, epoxy is totally inappropriate for this application, far too brittle and with almost no sealing capability. I have no quarrel with it for countertops but definitely not for studs through hulls.

As I pointed out earlier, if your friend applied Sikaflex over a silicone sealant its curing would be inhibited considerably, probably indefinitely. Silicones are best avoided on board as they have similar effects on many paints and adhesives.
 
gregcope said:
Hi

My anode stud moves and I had to remove it to take the nut off.

So now to replace what should i use to seal it on replaxement?

sika (or PU40)? Silicone? Epoxy?

Fancy sika as i do not want to replace it again. Nor do I want it to leak...

Also, apon inspection both grounding wires were damaged either along their length or at the crimp (insufficient support). Worth checking yours.
Click to expand...
The sealant recommended by Anode Outlet is Arbokol 1000. A polysulphide

.
 
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