Stripping old bottom paint from a Cape Dory Typhoon
The yard workers got around to taking Cantaora off her ill-suited and broken down old trailer onto a few jackstands. This gives me easier access to the boat bottom to start stripping her old bottom paint too now that her topsides was completely stripped of old paint.
Stripping a boat bottom of old anti-fouling bottom paint is a miserable, time-consuming job so I've learned to first get almost all the old ablative paint off with a chemical stripper called Peel Away. The stuff is not cheap but the cost evens out if you consider the yard time that is saved. I made a point of applying the stripper a little heavier around the areas that are harder to sand, including tight curves.
Sold in kit form, Peel Away is highly caustic water-based putty that is spread on the hull bottom over the ablative paint (I apply it with notched trowel first before smoothing it all out) then covered with 3'x3' plastic sheets (comes with each kit) and left overnight.
The next day, the caustic putty and bottom paint rinsed right off with a pressure washer leaving an ankle-deep orange puddle under my boat.
Of course, I am doing this on the hard in one of the last DIY boatyards around, that used to be a Navy yard for decades, with little environmental concerns but using a chemical stripper may be prohibited in other places.
There were a few stubborn spots that needed closer attention but the boat bottom was easily cleaned this way overnight, and the next day I used Dusty my go-to drum sander to go over what was left with one pass of the 40 grit, exposing an old below-waterline repair but no osmosis blisters.