I started a bottom job on my M-17 it is a 1974 model, I have kept it in the water all year for the last 5 years, I will pull it out for 2-3 months a year for annual cleanings. After much research I will be using the Petite Hydrocoat this year. It is a waterbased ablative and according to the specs should work great for me. As with any other job preparation is the key to success. With that in mind I removed the center board, since this also needs to be scrape, refaired and painted. I did run into a snag this year, after sanding off the old paint I noticed a lot of little circles in the gelcoat, these were the size of a pencil eraser, at first I thought I had hit another coat of paint, unfortunately it was the gelcoat. They were not blisters, just circles of cracked gelcoat. Probably did blister but then when I pulled the boat out and let it dry, the blisters receded and left the cracks. I guess this had been going on for a while but I never noticed since I normally just knocked off the old loose paint and applied the new bottom paint. It was not until now that, since I am going to be using a different type of paint, I decided to sand all the way to the gelcoat. So as you can see completely removing the old bottom paint is not necessary but every once in a while removing all the paint can expose problems that would be easy to miss otherwise. I will be sanding away about 90% of the bottom gelcoat and then going with a barrier epoxy paint, yes this is a lot of work, but I would rather do that to my 17' Monty then to 40' full keel monster. LOL thank goodness for small boats. Gilbert 1974 M-17 Sagitta -----Original Message----- From: montgomery_boats-bounces@mailman.xmission.com [mailto:montgomery_boats-bounces@mailman.xmission.com] On Behalf Of August Trometer Sent: Friday, March 23, 2012 10:44 AM To: 'For and about Montgomery Sailboats' Subject: Re: M_Boats: Bottom paint An "Ablative " paint slufs off over time keeping the bottom relatively clean, and is mostly gone. A hard bottom "Epoxy" paint has anti fouling in it and when it's gone, you still have the epoxy paint. After a number of years the build-up has to be COMPLETELY sanded off, the ablative just needs a light sanding. YOUR CHOICE - do you like sanding? -----Original Message----- From: montgomery_boats-bounces@mailman.xmission.com [mailto:montgomery_boats-bounces@mailman.xmission.com] On Behalf Of W David Scobie Sent: Friday, March 23, 2012 10:30 AM To: For and about Montgomery Sailboats Subject: Re: M_Boats: Bottom paint rick: i can't remember from prior posts if you keep your boat in-water for extended periods? if you don't keep your boat in-water for more than than about a month at a time consider one of the hard and slick bottom coats. larry yake uses this type of product on his M17, CORN DOG. i'm not sure the product or the details on how it stands up to long periods in water. larry does keep his boat in fresh water during the summer when he is not sailing the san juan and northern canadian waters. larry please share details and this time i'll save your information for my own future boat projet as 'what you did' is what i'm going to do when i decide to get under my M17 SWEET PEA and remove all the flaking bottom paint. :: Dave Scobie :: M17 #375 SWEET PEA - www.m17-375.webs.com :: Sage Marine - www.sagemarine.com --- On Fri, 3/23/12, Rick Davies <jdavies104@gmail.com> wrote:
My boat has ablative copper bottom paint that is over five years old, and beginning to wear off. One boatyard has suggested removing it with a pressure washer that uses very hot water rather than sanding. Does anyone have any experience with this, or comments as to whether it's a good idea or not? Any possibility of damage to the surface? Would it still have to be sanded before painting?
Thanks,
Rick M17 #633 Lynne L