I don't claim to be an expert in paint by any means, however, my very basic understanding of ablative paint is that it falls off as time goes by. That it does not necessarily inhibit growth but instead, growth on the paint falls off with it over time. Further, this is the reason ablative paints need to be renewed regularly as, once all that was put on has fallen off, nothing remains to prevent growth from building up on a bottom.
I understand hard paints to be different in that they don't fall off but instead typically contain a biocide designed to deter or inhibit growth, lead in the old days and typically copper now.
Michael Andrews
811 Bonito
-----Original Message-----
From: tuna-bounces at myfleet.org [mailto:tuna-bounces at myfleet.org]On Behalf Of VAURY Jean
Sent: Thursday, April 05, 2007 1:26 PM
To: Richard Reader; drmcdow at sfsurgerycenter.com; tuna at myfleet.org
Subject: Re: [Santana 22] How To Wet Sail and Be Fast
The article is 100 % wrong on saying that hard paints build up and not ablative (ablative make terrible cakes after a while making hulls ugly ad slow), at least the VC 17 that I have used for 9 years doesn't build up at all, I know it is not the best on the fouling protection but in area where the water is clear and warm at least a few months a year, including Chicago where we sailed the boat a few years
and the VC 17 M version with Biocide is getting close to the fouling qualities of the best other hard paints
Jean
_____
De : tuna-bounces at myfleet.org [mailto:tuna-bounces at myfleet.org] De la part de Richard Reader
Envoyé : jeudi 5 avril 2007 12:35
À : drmcdow at sfsurgerycenter.com; tuna at myfleet.org
Objet : Re: [Santana 22] How To Wet Sail and Be Fast
Craig,
Webster's defines ablate as "to remove or destroy especially by cutting, abrading, or evaporating". As I understand it, ablative antifouling paint works by gradually releasing biocides and metals (copper) that are contained in the paint into the water over time to create a toxic layer that discourages the nasties from attaching to your hull.
Try this link for a description of the difference between "ablative" and "hard" antifouling paints: http://powerboat.about.com/od/hulls/a/lowdn_botpaints.htm
(I'm sure someone will have a better, more accurate explanation out there.)
Richard
----- Original Message ----
From: Craig McDow <drmcdow at sfsurgerycenter.com>
To: Richard Reader <richard.reader at stanfordalumni.org>
Sent: Thursday, April 5, 2007 11:59:50 AM
Subject: RE: [Santana 22] How To Wet Sail and Be Fast
TO all tuna's
Curious about the word 'ablative'. In my 'world' ablative refers to removal of a surgical specimen...how does the word ablative paint relate?
I had a sprayed on bottom for the CYC midwinters but as luck would have it (Pat recalls) the ebb on Sat and Sun was 5.4 and 5.1 respectively and the wind was, uhh, nonexistent. So I don't know how much improvement I'll really have. My bottom had never been taken down to the gel coat since it was placed (1971) the keel was absolutely awful.
Will let y'all know after a couple of Friday niters.
Sure enjoy the Tuna emails...hope to get out for some Class races this season. Kids are now 3! Today's their birthday.
Craig McDow (Sweet Reward)
_____
From: tuna-bounces at myfleet.org [mailto:tuna-bounces at myfleet.org] On Behalf Of Richard Reader
Sent: Thursday, April 05, 2007 11:17 AM
To: Pete Trachy; List Satanna 22
Subject: Re: [Santana 22] How To Wet Sail and Be Fast
Just to be clear, "Pettit Vivid" is not one (i.e. hard bottom) paint--it's the brightly colored version available for more than one type of their antifouling paints. Specifically, you can get "Vivid" flavored ablative anitfouling, hard antifouling, speed antifouling and aluminum antifouling.
I point this out because I was confused when I saw an ad for Pettit Vivid ablative antifouling paint after reading Pete's email.
Richard
----- Original Message ----
From: Pete Trachy <pete at tolachi.com>
To: List Satanna 22 <tuna at myfleet.org>
Sent: Wednesday, April 4, 2007 12:11:09 PM
Subject: [Santana 22] How To Wet Sail and Be Fast
Summary: Ablative paints are SLOW. Get a sprayed hard bottom. Your bottom is only as good as the prep work, spend an afternoon fairing it with a 3M fairing board.
I think that there are a few people in our fleet who have been unduly frustrated in their quest for speed. Faired keels, new sails, and years spent sailing still leaves the top of the fleet out of reach. I personally think that bottom work has done more to take me from being consistently last in the fleet than anything else, including new sails.
Many of the wet sailed boats, including mine when I got it, have a traditional ablative bottom paint. This paint is soft and rough. Even though I was cleaning my old ablative bottom before races, it's cratered surface was never going to be fast. From what I understand, this type of thing is very difficult to avoid with an ablative bottom as the paint gradually flakes away.
A hard paint will maintain a smooth surface over the life of the paint job and not flake off like an ablative. You will also be able to to give it a light wet sanding with 600 grit to make it super smooth before it leaves the yard.
Steps:
1: Remove all of your old ablative bottom paint. It will bleed through and screw up your new hard paint. This is a must first step.
2: Your bottom is now down to gel coat, spend a day or so going over it with a long board. If there are any divets etc... Fill them with fairing compound and sand them smooth. The end product is only going to be as good as the effort you put into this step!
2.5: You may need a barrier coat. Talk to your yard or paint manufacturer.
3: Pick a hard bottom paint and get it sprayed on. Get it sprayed. Sprayed is smooth, sprayed is faster.
4: Give your bottom a light sanding with 600 grit after it has dried. Light, we don't want to take too much off.
5: Clean your bottom before every race you care about doing well in. And make sure your diver is treating it well. Pettit vivid should only be cleaned with smooth carpet, I think I am going to use a sponge this year.
Paints: I personally like Pettit Vivid because it comes in white which is easy for me to clean. Michael Tosse at Svendsen's recommended Proline 1088 with graphite mixed in. Kim Desenberg at KKMI says they like Micron 66 which he thinks is harder than vivid. I'm sure there are other solutions. The key is to get a hard paint and prepare the bottom well.
Tools: 3M makes a great fairing board. It made a huge difference when I was working on my keel. I have one that you can borrow.
Don't let your yard push you around into doing what is easiest for them. If you have questions ask the list.
Finally, I want to point to the results at the last Scombridae Sunday. Kevin McElroy and his brother Darren got 3rd of 8 boats in the after lunch racing. I know that Kevin only got the boat last fall and just started sailing a year and half ago. This was the first time he had raced the boat. He just got a sprayed Vivid bottom (yellow as you may have noticed) and cleaned it that morning. Old sails, no rockstar crew, just some hard work in the yard and a smart young man at the helm.
I think that getting the right bottom on the wet sailed boats in our fleet will make the racing tighter and more fun for everybody. Clarifications, corrections, personal experience... let us know.
Pete
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