Bottom Paint

Will · 04-02-2006, 12:18 PM

As far as bottom paint goes on Winni, its a common practice, not necessarily to prohibit growth but to just provide a better look. With that said, if your going to do it, you need to do it right. Just dewaxing and slapping on paint is not the correct way to do this. First the bottom must be dewaxed, with something like a fiberglass solvent wash, a 202 maybe. Then it needs to be scuffed up, usually you would use a coarse sand paper just to scuff the surface. Now we are ready to apply our first layer, an epoxy bottom coat. Why do you need this? Because, gelcoat on the bottom alone is not enough to seal the hull, gelcoat by nature is a porous substance. If water gets behind the gelcoat, between the fiberglass and expands you now have an osmotic blister. The barrier cote will provide an epoxy layer over the gelcoat to seal it. Once this is done you can go ahead and throw on a bottom paint. My recommendation is an ablative paint, which will wear like a bar of soap as you run the boat. What this accomplishes is no need to sand next year or at least a lot less sanding when you reapply paint. With the regular hard paints, once the copper is out of it, they are no longer effective, but the paint is still there. In turn you now have to sand that as the paint builds up over the years which is not a fun job, hus I recommend the ablative and just touch up where needed every year. Also just a tip, when you tape off the waterline, once the tape is on there, get a dry rag and rub the tape all the way around, this is called burnishing the tape and will give you a nice clean line all the way around.

Good Luck!

04-02-2006, 12:18 PM	#1
Will Senior Member Join Date: Apr 2004 Location: Mass. Posts: 63 Thanks: 0 Thanked 0 Times in 0 Posts	As far as bottom paint goes on Winni, its a common practice, not necessarily to prohibit growth but to just provide a better look. With that said, if your going to do it, you need to do it right. Just dewaxing and slapping on paint is not the correct way to do this. First the bottom must be dewaxed, with something like a fiberglass solvent wash, a 202 maybe. Then it needs to be scuffed up, usually you would use a coarse sand paper just to scuff the surface. Now we are ready to apply our first layer, an epoxy bottom coat. Why do you need this? Because, gelcoat on the bottom alone is not enough to seal the hull, gelcoat by nature is a porous substance. If water gets behind the gelcoat, between the fiberglass and expands you now have an osmotic blister. The barrier cote will provide an epoxy layer over the gelcoat to seal it. Once this is done you can go ahead and throw on a bottom paint. My recommendation is an ablative paint, which will wear like a bar of soap as you run the boat. What this accomplishes is no need to sand next year or at least a lot less sanding when you reapply paint. With the regular hard paints, once the copper is out of it, they are no longer effective, but the paint is still there. In turn you now have to sand that as the paint builds up over the years which is not a fun job, hus I recommend the ablative and just touch up where needed every year. Also just a tip, when you tape off the waterline, once the tape is on there, get a dry rag and rub the tape all the way around, this is called burnishing the tape and will give you a nice clean line all the way around. Good Luck!