Another question about bottom paint!!

[donhaller]

I have read through many threads on bottom paint, but my specific question is not really covered or I just missed over it.

1) How do I determine what kind of bottom paint is currently on my boat? It is currently a black semi-matte finish that is evenly covered with only a few places that are chipped or worn showing the old blue colored bottom paint.

2) Any suggestions for a bargain paint that would be a good choice for the middle Chesapeake bay around the Annapolis area. West Marine has a lot of paint sales right now, I just don't know what to buy. I don't even know if I really need to do this as the bottom was painted just over a year ago. It has been out on the hard since December.



Thanks

[arf145]

It sounds like you weren't the one who did the last paint then. Which means the paint on there might be a single season paint that is no longer an active biocide. If it were me, I'd paint, rather than splash it with an unknown.

[T37Chef]

If the old paint is unknown and in good shape: Clean, remove loose paint, sand (80 grit paper) and rinse with water. Apply a tie coat primer such as Interlux Primocon or Pettit 6627 to ensure optimum paint adhesion. Then simply apply the antifouling of your choice. Some slippery Teflon paints such as the Interlux VC Offshore series may need to be removed before applying a noncompatible paint.
If the old paint is unknown and in bad shape: Remove the old coats of antifouling paint. If the hull does not have an epoxy barrier coat this is a good time to consider applying this protection. Then proceed with painting.
West Marine: West Advisor

BTW...Bacon Sails in Annapolis has a awesome sale on some decent bottom paints. You should call them for pricing.

[donhaller]

I suppose that means I have to pay to have it sanded. Where I keep my boat they require a vacuum sander which I don't have. I guess I could rent theirs, but then I need to get some tyvek coveralls and a mask too.

[donhaller]

Originally Posted by arf145

It sounds like you weren't the one who did the last paint then. Which means the paint on there might be a single season paint that is no longer an active biocide. If it were me, I'd paint, rather than splash it with an unknown.

Correct... I bought the boat in November from a guy that really only owned it a year. The dealer that sold the boat to him painted the bottom for him before it went in the water. The PO had no idea what paint was on the boat when I asked him.

[arf145]

I had the same situation last year. Mine felt a little soft, which I took to be ablative. You don't really need to sand so much as just roughen the surface a bit. Do they require a vacuum sander for that?

[hellosailor]

It looks like a generic ablative paint. Best to go like T37 says, sand, prime, paint and as long as you're using another ablative, you most likely are fine.

There is another option to sanding. The paint strippers that you spread on as a paste, cover with a special paper, and then peel off the next day. No dust, just bag the debris and throw it in the hazmat dumpster. Put a tarp on the ground and scrape off whatever is still there and gooey afterwards.

Some folks say the "marine" strippers work best, others have used the hardware store brands quite merrily. Apparently it depends on what's on your boat, and I'd suspect that if you're just trying to get off the generic ablative paints? Any of them would do a good job. Unless you're looking for a mirror-finish racing bottom, which is going to require lots of sanding.

[sailingdog]

Be careful of using "hardware store" paint strippers, as many are stronger than the marine paint strippers and can damage gel coat.

If you really want to start with a clean slate, I'd recommend sodablasting the bottom. Then you can prime and paint from a known good surface.

[Sailormon6]

It’s hard to tell from photos just how bad the old paint is, or what type of paint it is, but the overall condition of your old paint doesn’t look too bad to me, unless you’re into racing. If you’re a racer, I’d strip all the old bottom paint. If not, I’d suggest you wet sand the bottom overall, but spend more time on the areas with the orange-peel surface, as shown in your first photo. I used a green colored sanding disk that I get at WM, Fawcett’s and other places. They cost about $4.00 each, but I only used two to heavily wet sand my C&C 35. I thought machine sanding was the faster way of removing old bottom paint, but found that wet sanding removes it as fast, but it's actually easier, because you don't have to hold the weight of the sanding machine up against the hull for hours, and you don't have to wear a respirator.

If you only want to smooth the surface of the old paint, I'd wet sand it. If you want to remove all the old paint, and it isn't too thick, I'd use chemical stripper. If you want to remove a very thick layer of old paint, I'd suggest that you hire it done. Your marina manager knows a guy who does it.

Since you don’t know the type of paint that’s on it now, I’d play the odds. The probability is that the old existing paint is some kind of a hard finish paint that can be covered over with a reasonably good ablative bottom paint. I’d wet sand the bottom, and put one or two coats of ablative paint on it, and see how it looks after a year. If it doesn’t peel, you’re good to go. If it peels, then all you have to do is remove what’s left of one or two coats of ablative paint, which should be easy to remove.
If you strip the bottom, don’t use one of the ordinary paint strippers that are sold in most hardware stores. It’s too aggressive, and might damage the boat. If the bottom has gelcoat, it will dissolve the gelcoat if left on too long, but there are strippers that are specifically designed for fiberglass. Interlux makes one, but, like all "yachting supplies," it's very expensive.

The paint stripper that I use works as well as any I've found, costs about $25. a gallon, or less, and is available nationwide. I use Klean Strip paint remover. They make different types, but you want the type that is specifically designed for stripping paint from fiberglass. I have used it to strip two boats with excellent results. I couldn’t find a paint dealer in the Chesapeake Bay area that stocks it, but special-ordered it from a paint dealer. (The company’s website might suggest a local dealer for their products.) There's no really easy way to strip old bottom paint, unless you hire someone else to do it for you, but a paint stripper is the quickest, easiest way I have found.

[donhaller]

Originally Posted by cardiacpaul

"The dealer that sold the boat to him painted the bottom for him before it went in the water."

Uhhh, call the dealer and... ask 'em say... whudya uze anyway, huh? ".

I don't know the dealer, and the recent history and PO are sketchy at best.