Hi Mark,
After 16 years I had the bottom of Kimberlite cleaned down to the gelcoat. I did not want to use any form of blasting. I had the yard use a chemical stripper available at Home depot to remove paint down to the gelcoat. It took time and multiple applications but it worked and the bottom came up quite clean. I think the paint we removed weighed somewhere between 3 and 400 pounds and it was ablative paint..
I then had the yard apply 4 coats of interprotect . They then applied a hard epoxy blue paint and then 2 coats of black ablative paint. worked great . We hauled this year after 2 years and the bottom was beautiful. I would suggest using the chemical stripper when it is warm as it is a chemical process.
Fair Winds,
Eric
SM 376 Kimberlite

On February 25, 2020 at 2:28 PM Mark Pitt <mark_pitt@...> wrote:

I have owned my Super Maramu since she was launched in 2003.  Amel applied a hard bottom paint before launch in 2003 but since then I have only used ablative paint.  The layer is now thick and a bit uneven.  Having carefully examined the words of caution on the Amel owners group, particularly those of Joel Potter, I have looked in vain for a soda blaster to remove all the old bottom paint. I just cannot find one in Rhode Island.  The contractor recommended by my Rhode Island marina uses glass and is apparently very experienced with blasting boat bottoms. 

Last week I contacted the large Hinckley repair yard in Portsmouth, RI and it turns out that they do not have access to soda blasting either and use the same glass blasting contractor used by the full service marina where Sabbatical III is stored.  Hinckley recommends the glass blasting followed by 5 coats of epoxy (the 5 coats is their rule for European boats).  My yard has suggested 3 coats of epoxy as a water barrier.

I had been hoping for soda blasting plus a single coat of epoxy as a primer, on the assumption that the barrier coat under the gel coat would remain intact.  I did not expect that it would not be possible to find a soda blasting contractor in Rhode Island (or nearby Massachusetts) who works on boat hulls.

 

Any suggestions for me?  I feel stuck and am inclined to use glass blasting following by 3 or more coats of epoxy as a barrier coat.

 

Mark Pitt

“Sabbatical III”, SM#419, Wickford, Rhode Island, USA