Once epoxy gets out of control it gets real messy, real fast. It needs accurate mixing, drips, runs, and sticks everywhere but where it should. Accurate thickness will be difficult to achieve. Leave a pot too long and it becomes unusable and can even catch fire.
At a minimum the hull
will need to be taken back to bare gelcoat
and keyed. I'm assuming that you want to do this because there is some "osmosis". If so the blisters
will need to be "removed" the underlying fibreglass dried and the resultant holes filled. I seem to recall
some boats taking many months to dry out before the holes can be filled and the barrier applied. This not a simple job.
All of the above needs to be done in to tropical heat and overhand. I hate to think how many square metres of hull there are in a 46' cat.
I've heard reports that some professional barrier coat jobs are of indifferent quality while others are superb with no further problems occurring. If the professionals have trouble getting it right than what sort of result do you expect?
While my wife has been more than happy to assist with antifouling I've found she is much happier doing almost anything else...
I would seriously question the necessity to do this as you pick up a new to you boat. If the need is so urgent surely you would not be buying
the boat. The logistics and effort involved are mind bending.
If there are a few blisters
why not leave them. Get the local workers to splash on a few coats of Primocon or whatever they use as a sealing primer there, then antifoul. Use your time and energy to check that they have all needed materials and put on the required thickness. Make sure they know there's a slab of beer
in it for them when they finish. Also check that you have the required ingredients for your favorite cocktail when the boat goes back in the water
Ask round as you have time, find who does the best barrier coat, and next time you have to come out of the water
Unless you want to be part of the local folklore for the next generation.