antifouling falls off - need advice!

[mibbal]

Mates, I need your advise...

Two ears ago my hull was sandblasted up to gel, and 5 coats of epoxy primer was applied before AF. The boat was on water for 2 years without any problems with antifouling.

Now, after lift out and cleaning the boat with pressure cleaner, the hull looks like on a picture - there are many places where antifouling fall off.

Marina guys propose sandblasting again and apply new primer + antifouling, and insist that there is no other good option. I don't like the idea to sand out my 5 layers of epoxy primer, which was quite expensive job to apply. 

Is it really no other way to apply new AF on existing epoxy primer?

[Yngmar]

Huh, why not? Nobody wants to sand anymore, the most character building part of boat ownership? 

It's epoxy primer, should last pretty well. You sand it to key and put your AF on, checking for compatibility in the instructions. 

[elias]

In a similar case in the past I used a generic vinyl based primer to patch between I'd antifouling and epoxy primer and worked great . It is a Greek made one , nobelac vinyl primer

[Happysailor]

To me it looks like something went wrong between the application of the final epoxy layer and first layer AF... if the final epoxy is fully dried out the "tack" to AF is low. This is also why e.g. International advises to apply the first layer of AF with still wet last layer epoxy. If this is not done, epoxy will continue to cause issues. Very likely with HP jet you can get all the epoxy off. There are multiple scenarios possible, consult your paint supplier. Either sand the epoxy or apply a buffer coat like another epoxy coat or Primocon (yes I am an International fan for over 25 years...) before applying new AF. For sure you don't need to have your whole epoxy system removed. It sticks well to the hull isn't it. Don't fix what ain't broken!

(If you had the job done by the same Marina guys, perhaps even a warranty case?)