First boat; starting renovation: paint on the bottom

[JudoJNoble]

First boat; Starting Renovation: Bottom paint Mildewed?

(For those not interested in backstory, my actual question is in the second post, below.)

Ahoy-hoy!

I must admit, I've been a lurker for years, visiting the forums occasionally as I dreamed about owning a Catalina 22 for my first boat, not only for the craft itself but the community of helpful people I've seen. I'm glad to say I finally have a reason to join and post, as I now have my own vessel.

I found it on craigslist, initially listed as ready to sail. After making the 1.5 hour trip to see it, however, I found something quite different. The boat had been sitting in a field for a few years (last reg sticker on it is from 2009) full of water, detritus, and thousands of creatures who love such conditions.

Despite the misleading listing, I agreed to help the owner move it to his sister's house, where I would help him clean it up and we'd settle on a price for the boat. After towing it over an hour and a half, one of the wheels fell off of the trailer... literally as I'm backing it into his sister's driveway! Even as I fretted over the consequences if that had happened while driving, I realized some sort of providence was with me that day. And, oddly enough, I started to feel as if I were meant to own this boat. I replaced the wheel bearing, and looked forward to getting the boat in shape to sail.

Yes, I know to this point I was a bit naive, and being taken advantage of. But the owner was an older fellow who seemed to have trouble getting around as well as he used to, and I've always been a sucker for anyone who could really use my help. Anyway, after the fellow gave me more and more reasons to be concerned about dealing with him over the following months, I decided to trade him my motorcycle and some money for the boat and trailer, got bills of sale and the titles filled out, and brought my first boat to my house to work on myself.

Anyway, since I know people love photos, I'll attach a few of the "before" pics here, and go on to my actual question in the next post.

 

[JudoJNoble]

So after it sat through another winter with water in it, I decided it was time to get to work on my latest project. After all, I can continue finishing my basement into a home theater/man cave when the weather doesn't let me work outside.

I began by pumping out as much as I could with a "sump" style pump that didn't seem to remove as much water as it should. So after adding another couple of layers of OFF to my skin, clothes, and hair, I stepped down into the murky mess and detached the bilge pump. After taking it apart and getting it to work, I put the pump back in, connected it directly to 12V, and snaked all of the mud daubers, spiders and other blockage out of the drain hose. As the water was pumped out, I also started removing pretty much everything that wasn't screwed/glued down, and plenty of stuff that was.

Once that was mostly finished, I started in with the pressure washer. I couldn't get the washer's venturi to suck any of the bleach/TSP solution into the tube, but even with just water the change is quite heartening. After about 4-5 hours of constant washing, I still have a few hours to go of pressure washing with just water before I move on to anything else. A few pics are attached to show some of the difference.

Now for my question:
There is clearly some heavier blue paint on the bottom, which I assume to be anti-fouling paint. As I cleaned it, the pressure washer seemed to take a whitish layer off of it. I assumed this was just what the mildew looked like on the blue stuff, but when I wiped it with my finger, the slimy residue was a whitish blue. Also, as I kept the washer on the green stripe around the waterline for a few extra seconds, it cut through the green and revealed blue. But it was significantly harder to cut through the "waterline green" than most of the growth on the boat. So...

1) Is that likely anti-fouling paint on the bottom? If so, am I going to need to remove that and apply more?
2) Is there any likelihood that pressure washing the bottom would damage the paint in any way, or is that whitish-clear/bluish layer that is coming off merely the mildew growing on the blue paint?
3) What is the green "waterline" stripe; and if it should be removed, why is it so much more stubborn than most of the rest of the mold/mildew?

You can see in the pic of the underside: both where the white stuff was coming off of the blue (with some effort) and a patch where the pressure washer cut through the green band to the blue (with more effort).

Thanks in advance!

 

[caguy]

I'm no chemist but it looks like it is probably copper in various states of hydration. I wouldn't be surprised if the blue color coincides with the level of the water you found on the inside. The white is likely oxidized gel coat. I would sand it smooth and repaint with a hard ablative bottom coat. The paint comes in black and red (rust) and will not rub off on your clothes when you accidentally bump it like the green. Use an orbital sander with a vacuum hose attached. If funds are limited Harbor Freight is a good source or block sand with wet and dry and a running hose.
Since you are trailering there should not be a need for a barrier coat.
Keep the faith my Luger 30 looked worst than that.
Welcome to the board.

 

[JudoJNoble]

Thanks a bunch for the response, and for the welcome!

I'm no chemist but it looks like it is probably copper in various states of hydration. I wouldn't be surprised if the blue color coincides with the level of the water you found on the inside. The white is likely oxidized gel coat.

How could water inside the bilge affect the color of paint (or whatever) on the outside of the hull? Particularly, how would it do so with fiberglass between them? I ask because I'm genuinely curious, and would really like to understand the reasoning (even if that isn't the cause, in the end). I don't think the water level in the cabin/sole was the same as the water level in the bilge, but I can't be sure what level the water was in the bilge offhand.

Also, the blue (and green) seems to be a very different texture from the smoothness of the gelcoat (white) everywhere else, which is why I assumed it was anti-fouling paint. I assume that's where you expect the copper would be from? If so, would the green band maybe be where the boat sat in the water before? I assumed it was a waterline issue. But I suppose it could be how the waterline reacted with the copper in blue antifouling paint, instead of being a different sort of growth? So with it giving way to blue, given enough focus from the pressure washer, would that likely be a removal of the oxidation from the top layer of paint? If so, would taking it down to the blue be a good thing?

And what do you mean about the green accidentally coming off when you bump/rub it? Does the green (and/or blue) antifouling paint tend to rub off, while the black and red don't?

As far as the white being oxidized gel coat... is there typically a layer of gel coat over the antifouling paint? Or is the more textured blue bottom really not likely to be antifouling paint?

I apologize for all of the questions, as I try to work through understanding what's going on here. Thanks again for the input, the welcome and encouragement, and the possible explanation.

 

[caguy]

Anhydrous (without water) copper sulfate is green when hydrated it turns blue. Fiberglass is permeable to water. Without being there it seemed logical to me give the height of the rain water in one of you pictures.
The white on all of the old boats I've restored are coated with oxides gel coat. When you wash them especially with a pressure washer the stuff runs down the sides.

If you want to put a lot of work into it you can sand it down to the gel coat and eventually polish and wax it. You will save money but will spend 3 days under the boat. The easiest thing to do in my opinion is to sand off the green coat and use a hard ablative paint.

The blue green ablative paint does come off on everything your hands, clothes etc. I borrowed a rudder from a friend once that was painted with that bottom paint and it got all over my pants, shirt, hands and face. I looked like a Smurf.
Here are few of the Luger 30 and bottom paint job,

http://s294.photobucket.com/user/xcaguyx/library/Luger Sailboat?sort=3&page=3

 

[JudoJNoble]

Thanks for the reply!

Looks like you did a great job with painting yours. That yellowish band at the waterline in the first pic of yours takes me back to my initial thoughts about the green being a result of yellow waterline scum on the blue paint.

Conversely: as dark as the green at the stern (though it's lighter yellowish on the rest of the hull), and as difficult as it is to remove... I have wondered if maybe they actually painted a green boot stripe over the blue base coat. Especially since it gave way to blue in that one spot with enough focus from pressure washer. But isn't the second/top coat -- assuming contrasting colors between layers of antifouling paint -- usually the larger area on the bottom of the hull, as opposed to being just the boot stripe (which sometimes seems to be the base coat color)? Your pictures reinforce that notion, but I admittedly know very little about it.

Thanks again for all your help!

 

[caguy]

The yellow line at the water line is what is was left of the old ugly yellow boot line. You can notice that the boat stripe below the rub rail is also yellow, ugh.

Eventually I would like to paint the topside dark blue with red lines. The gel coat polished out nicely and that may never happen.

Try some bleach on the green area dilute 4:1 that removes algae effectively. The bottom paint goes on quickly and easily, but as all paint jobs the work is in the prep,

 

[JudoJNoble]

Try some bleach on the green area dilute 4:1 that removes algae effectively. The bottom paint goes on quickly and easily, but as all paint jobs the work is in the prep,

I tried rubbing a couple of different areas with a towel dipped in a bleach+TSP solution.
You can see the effects it had on the whitish layer in the below pictures:
Before

During

After drying




This is how it worked on the green layer around the waterline:
During

After drying (two days later)

You can see the "before" by looking on either side of the area that was cleaned.


And here is a closeup of the stern, where you can see some of the paint layers through the chips:


Would abrading paint come off with a power washer, or being scrubbed with a TSP/Bleach dipped towel? You can see the blue color rubbing off on the towel, but how much of the paint really comes off? Still trying to determine if that green swath is a purposeful boot line of sorts, or just yellow fouling on blue paint.