It can be done, certainly. Why ever not? Loads of people have it done - principally as part of osmosis repair or prevention, prior to the application of the specialist solvent-free epoxies used in this process.
All of which I have done myself on many occasions. (Horrible job, even with all the right equipment!)
It is a bit of a 'big one', though.
While some people consider 'elbow grease' to be an option it is not only a desperate one but quite dangerous too. Bearing in mind the hazardous toxins you would become covered in.
'Nitro-Mors', the paint stripper manufacturers even tried to market a version for this a decade or more ago. It was a right old palaver. Involving covering the whole underside with newspaper while the product 'took effect' (which it didn't anyway), and great expense and waste of time. I mean, it worked fine on thin, but barely at all on anything thick - which is rather the point!
There are really only two ways and the first is to prevent it from building up in the first place!
Paint manufacturers, particularly for boats, love to get people plastering the stuff on as if it was going out of fashion. Fine for a really high-grade finish on your topsides and superstructure, so it won't ever need doing again if well looked after and regularly polished, and even below the waterline beneath the antifoul - eg: the aforementioned epoxies, but unnecessary for antifouls themselves. Any antifouls!
Put one coat on to begin with (two at the very outside) on a new, or freshly prepared vessel and with the exception of really specialist products such as the racing teflons, silicone coatings and copper-bearing epoxies, use a 'self-polishing' product that will remove itself as you cruise. (that's basically how these work).
Then each season - and here's the golden rule - don't put too much on - after scrubbing (and with self-polishing products, that gets it off) at the end of the previous season, come the next, you maybe only need to apply a good band, say two-to-three feet deep all the way around, from the waterline down.
Maybe deeper, maybe not. Maybe even all over. Just gauge it as you go, each season, and try to maintain it at a strength (thickness) where needed that is appropriate to your usage and particular local fouling conditions.
Removing to start with:
You first need a yard that has no problem with the following (some haven't got the space, and have other issues).
Next, find an abrasive cleaning operator who really knows how to do their job. This is absolutely essential. The best way is to get recommendations, even try to witness the results of work undertaken. The operators themselves will refer you to the jobs if they are any good.
And get the vessel eggshell-blasted.
There is real finesse involved in this. There are plenty of people who do it, but unfortunately some of them fail to appreciate this latter.
And that is the one main thing to watch, because a blasting set in the hands of a poor or gung-ho operator can be very destructive. And I've seen many superb and a few dreadful results.
The thing you must strongly emphasize to the operator is that you are not having it done for osmosis repair, (or bottom replacement!) just for paint removal. (Think of Michael Caine in 'The Italian Job', kind of!)
Blasting is no different to any other abrasive cleaning process in that there is an infinite gradation of 'cuts', from course to fine. And depending upon the material used for the blast, the pressure applied at the nozzle, and the volume of particles introduced to the blast-stream, you can either end up with a superb, clean, nicely abraded surface for new work to commence straight away (at which point, refer back to my first comments), or virtually no lay-up left on the vessel's bilges!!
So no messing about, get it eggshell blasted, and thereafter keep the build-up to a minimum.
The new(ish) epoxy antifouls are excellent. They contain copper particles and following initial application, all you do is very lightly abrade them with wet-abrasive paper each season. To expose new active ingredients. No need for repainting. Well, hardly ever - and that's got to be good.
By the way, the blast operator must ensure that the vessel is thoroughly enclosed in either a tent, or partitioned off behind fences of tarpaulin or similar, as well as carrying out the work on a windless day, preferably with some light rain (having also covered / dust-sheeted the boat), in order to minimise inconvenience to other people and their vessels, nearby - another reason for engaging the services of a real professional, not a 'cowboy'. [No offense, US readers, it's an English expression for someone who doesn't really have a clue as to what they are doing! ]
And good marinas and yards have areas specially demarcated for blasting operations, a good distance from other customers. They will often do the job for you themselves using their own, or freelance skilled operator.
These yards are the place to go and have a look at some results, prior to considering the option. It is a very familiar - almost the only in fact, but certainly most widespread - practise for repairing osmosis, where not only the paint, but some of the gelcoat and / or glass lay-up also will need removal - how deep being determined by the extent of the osmosis, but in turn therefore, depending upon the skilled hand and judgement of the operator.
BTW, Perhaps they were 'expert' in another field!
Edit: It makes no difference if it is a dinghy even - if you feel it needs doing. A good blast-cleaner will be only too happy to do it, and do a perfectly good job. Clinker built dinghies are quite often done this way - inside and out. Consider how difficult it is to remove all the paint down to nice, clean virgin timber from such a construction by hand, if you wanted to epoxy-saturate or repaint it!
Edit 2: Apologies for the long answer, but I would not suggest an option that in unskilled or incompetent hands is capable of causing thousands of pounds worth of damage to someone's pride and joy, without first providing an appropriate selection of accurate background information and supporting intelligence.
Answered By: Girly Brains - 5/23/2010