Anti foul grit blast removal, your experiences welcome

[DAKA]

Cobblers

Gel Coat is considered a semi permeable membrane, it as applied as a decorative finish and though some manufacturers do not use below the waterline (preferring to use pure un-tainted by pigment resin-which is more waterproof) it was found that the opaqueness of ungelcoated hulls (below w/l) was disconcerting, especially when in your berth you could not only hear the waves lapping at the hull but see them as well!
With the development of better resins used in the laminating process along with better gelcoats osmosis is not the concern of today's manufacturer as it won't happen within the warrantee period-or at least it shouldn't.

Osmosis certainly isnt a concern of the manufacturer , it never really was, it is the owner who holds the mucky end of the stick.........

the vast majority of GRP boats are well outside the warranty period anyway, and almost all the ones ready for antifoul removal.

Gelcoat is just a modified resin, if a coat of layup resin was substituted for a specialist gelcoat exactly the same rules would apply..........it would need to be thin enough so it didnt crack, it would need to be thick enough allowing for the bubbles so it wouldnt leak.

The reinforced strands in the GRP cause the layup resin to be porous/permeable forcing the use of a waterproof layer of gelcoat .

Even if pigment is used in the thin layer of gel, light will still shine through if pigment is not also added to the layup grp.

Anyone needing antifoul removed should study at close quarters boats that have been given such treatments and then study at close quarters a boat that has had the antifoul removed by Electric chisel.

It is like looking at a brand new boat polished fresh out the mould with a few micro thin smears of antifoul left .

Compare that with a soda/slurry/grit blast that looks like Emery paper riddled with pin holes.

This is of course great news for any entrepreneurs , boats without osmosis can have antifoul removed by electric chisel , it is a semi skilled job and a franchise network can be set up with minimal overheads just a little training on being careful around the chines, its not really a DIY job.

Boats that have already got osmosis may as well be grit blasted to wash out the blisters.