How to bottom paint???

[Gulfstar76]

I have purchased a 34' boat over 30 years old, the bottom was peeling in some areas and the surveyor recommended fixing this potential problem. I used a wood scraper and scraped the bottom paint ( not sure what it was but it was hard ) it also had an anti fouling coating of some kind. I am at the gel coat, what do I do now?<br />I will be mooring in brackish water that rises and falls 10' every tide change.The survey didn't show any blisters and I saw no leaking when the boat was pulled and dried out. Can I let theboat sit with the gel coat exposed over the winter?<br />Thanks

 

[trog100]

Re: How to bottom paint???

u need to paint the bottom with some kind of antifoul paint.. its not a hard job.. cleaning the old crap off is the hard part and u have already done that..<br /><br />when u leave a boat in the water maintaining the antifoul paint on the bottom is just part of the yearly routine..<br /><br />the paint is designed to ablate.. (partly wash off with use).. its the way the active chemicals stay working..<br /><br />basically no harm will come to your gelcoat if u dont antifoul.. but marine growth on the bottom will wreck the boats performance..<br /><br />trog100

 

[Captn Dave]

Re: How to bottom paint???

I assume you mean sit out of the water, over the winter? Yes.<br /><br />If I were you, since you're down to the gel coat, I'd put some type of barrier coat on before the bottom paint to prevent blisters. <br />The story goes; some boats get them, some don't.<br />Just because you don't have them now, doesn't mean you'll never get them. <br />If you do get them, you'll have to get back to where you are now, down to the gel coat.<br /><br />There are several products out there. Coal tar expoxy and also specific expoxies for protection. <br /><br />Whatever you do, thoroughly clean the hull with acetone, sand with 80 grit paper, and wipe down again before applying the first coat.

 

[Steamboat]

Re: How to bottom paint???

When you do apply the anti-fouling paint, pick two contrasting colors and paint the first coat in the color you like the least and then the final coat in the color you want everyone to see. The reason for this is to show when you need to repaint since the anti-fouling paint will wear away and if it's all the same color you don't know how much is left (may save you having to repaint every year).

 

[Gulfstar76]

Re: How to bottom paint???

thanks for the help<br />rick

 

[Stinger313]

Re: How to bottom paint???

Do yourself a huge favor and spend the money for a good multi-season paint.Im sure afer doing what you just did,you dont want to do that every season!!I use Interlux Micron CSC on mt 33 Carver and have had great results.

 

[trog100]

Re: How to bottom paint???

the problem with anti foul paint is the stuff actually needs to wear off to be effective.. its the way the chemicals that keep the wildlife at bay stay near the surface and do their job..<br /><br />how long it remains active depends on how much the boat is used and how much paint u put on.. some of it hardens too much if the boat is out of the water for too long and ceases to work and it has to be put in the water within a few hours of application..<br /><br />the stuff i use is a water-based ablative micron two-part certainly not cheap but it still says reapply every year.. it does work.. any bits that aint painted like the outdrive get covered in green hairy slime within two weeks of the boat going in the water but the bottom stays clean..<br /><br />if a boat is not left in the water for extended periods u dont need antifoul.. mine stays in the water all year round so it needs it.. basically apart from keeping marine growth off the bottom.. glass boats dont need any paint at all the stuff they are made of is quite water-proof as it is..<br /><br />the two basic dfference seems to be.. single part paint has to be put in the water within so many hours of application and kept in the water for the paint to remain effective.. if the paint is allowed to harden too much (out of the water) it dosnt release its chemicals properly and ceases to keep the critters at bay.. the ablative two-part stuff dosnt mind the boat being out of the water for extended periods of time and still continues to work until it simply wears off.. <br /><br />the really good put on and forget antifoul paint got banned for ecological reasons s few year back.. it was considered a little too affective.. its said by some that this is the reason for the large increase in zebra mussels and their like.. <br /><br />as an example.. my boat had been in the water for three years before i bought it.. no antifoul paint.. the bottom was entirely covered in three inches of freshwater mussels.. the boats top speed was about 15 mph with a wake like the queen mary behind it and it guzzled fuel like crazy.. when i cleaned the bottom the boat zipped up tp 40 mph .. i must admit to being amazed at the difference a clean bottom makes.. nothing like a lesson learned the hard way.. he he <br /><br />trog100

 

[Gulfstar76]

Re: How to bottom paint???

I understand the ablative part, I wasn't<br /> sure what is put on the gel coat before the antifoul paint. Your right I don't want to do this sgain. I bought a tyvek suit and a face mask and I still was covered with antifoul paint. What a nasty job. No one has answered my question as to leaving the gel coat exposed over winter? <br />You guys are very helpful, Thanks again

 

[trog100]

Re: How to bottom paint???

u simply lightly sand (Roughen) the gel coat to give the anti-foul paint something to key to and apply the anti-foul straight to it..<br /><br />nothing will happen to your gel coat leaving it exposed over winter.. <br /><br />if the original gel coat is in poor condition or looks a mess u can paint it with some two part epoxy paint to protect and make it look pretty but otherwise the anti-foul goes straight on the cleaned and slightly roughened gel coat..<br /><br />as for not wanting to do it again.. well.. if a boat is kept in the water for any length of time.. its something that has to be done every so often like it or not.. i did mine last year.. this year i will just inspect and touch up any worn areas that look like they need it.. <br /><br />trog100

 

[Stratocaster]

Re: How to bottom paint???

trog100, not all antifouling paint is ablative. There are just as many hard antifouling paints as there are soft. Obviously the hard paint doesn't need to wear away to be effective; it uses different technology to keep releasing active ingredients. Just to clarify.

 

[Gulfstar76]

Re: How to bottom paint???

I moor the boat in an outlet to the atlantic.This outlet ( the merrimack river ) freezes when the winters are very cold. All boats are removed because of the the ice. Our season is short. If the boat can stay with the gel coat exposed over the winter then next spring I'll coat the bottom.<br />we don't get a lot of slime because the tide in the river rises and falls 10 feet every tide change, this fast moving water reduces the bottom build up of slime and hard shell creatures.<br />Thanks

 

[trog100]

Re: How to bottom paint???

yes its not all ablative.. i just take the view that the ablative stuff works better.. i cant see any logical reason for it existing otherwise.. would anyone buy paint that is designed to wear off if there wasnt a valid reason for it.. i wouldnt..<br /><br />the hard stuff might stay on the boat longer.. but i doubt it remains active for any longer than a couple of seasons at most.. so it probably comes down to more work removing the old hard none active paint every so often to avoid exessive paint build up or simply applying another coat of the "wear-off" stuff with no need to remove the old one cos its mostly washed off..<br /><br />u takes your pick i supposed.. but u are right not all anti-foul paint is ablative.. just the sensible kind.. <br /><br />trog100<br /><br />ps.. i talk too much.. he he