corrosion

[bluefinch]

I have a 38 foot steel yacht that has had the underwater sections treated with a seven coat joton epoxy system. The base coat appears to be a zinc flame spray.

I am replacing some of the under water sections and was going to re-apply the zinc flame spray before joton epoxy, however a marine surveyor has advised me that he thought he had read somewhere a zinc paint would have an adverse effect re corrosion in salt water as the anodes were also made of zinc?

The existing zinc coating seems to have held up very well, could I have any advice on this matter?

 

[savageseadog]

Basically you would end up with electrolysis all over the hull under your paint system . Your paint sytem would lift and bubble.

 

[Will33]

Happy to help with this, if you want to send me a PM with your number, we will give you a call to advise you how to deal with this.

Kind regards

Will

 

[bluefinch]

Hi Will
thanks my contact number is 07781-124184
Mick Taylor

 

[ean_p]

so why would that be then ?

 

[bluefinch]

Zinc coatings provide good corrosion resistance assuming the adhesion is good and provide cathodic protection to small scratches or defects to the underliyng steel. Using Zinc anodes bolted or welded to the hull will back up this system, therfore, the zinc coating should not depreciate as fast and as the metals are the same should not cause any adverse affects.

(advice from M G Duff)