Damage to Coppercoat antifoulant when water jetting hull

[catmandoo]

Anybody got experience of blistering on Coppercoat epoxy antifoulant coating such that it comes off in patches when scraping or jet washing to remove marine growth. Original gel coat substrate in perfect condition

If so what did you do to repair the epoxy and what were the chances of more patches coming off in later years

 

[alan006]

I think this would be caused by the epoxy treatment put onto a surface that was either poorly keyed or damp/not cleaned properly. I have seen an epoxy treatment coming of the bottom of a boat in 6inch square patches when pressure washed. We blocked the boat up, steam cleaned the hull several times and got a surveyor to check the hull was dry enough before we re-epoxyed the hull. It is possible I suppose that it may have reacted with the layer it was put on so its always something to bear in mind.

 

[catmandoo]

Been on for about 6 years so must have had some adhesion . IN previous years noticed some blisters

 

[alan006]

I think you will be faced with a choice to either repair the coating at the places it has failed or to remove the lot and reapply it all. The choice will of course be up to you, but the deciding factor will be an educated guess as to how well the remaining coat is fixed to the hull.

 

[catmandoo]

Yes thats my problem . Material seems to be brittle . so may get away with it . Will have to talk to manufacturers / suppliers

 

[oldsaltoz]

Epoxy resin is far more brittle than standard resins when applied as a coating without cloth, that's part of what makes it stronger and less flexible weight for weight.

However your problem sounds very much like poor preparation or application. are the problem areas in any particular area or level / depth? Any sign of any residue when you pull a lump off, any pattern to the failed areas?

Sorry to hear you have a problem, let us know your findings please.

Avagoodweekend......

 

[doug748]

Two of my chums have this type of anti foul, both have had problems. They have patched it up and carried on regardless. Some manufacturers supply a small patch up kit for this...

 

[catmandoo]

Apparently backed on to Gel shield and Gelshield coming away . Also some spots with high moisture content Only alternative is to remove ,dry out and apply replacement epoxy coat

 

[oldsaltoz]

G'day Catmandoo,

Not the best outcome but at least you know what failed. Will you apply Gelshield again or go for an epoxy resin coat?

Avagoodweekend......

 

[catmandoo]

Will go for epoxy resin coat .

Problem is how to effectively remove Coppercoat which is very hard and brittle . careless blasting could damage hulls which are only about 1/4 to 3/8 thick in places .