Why paint a trailer boat from below? (2023)

Author	Topic: Why paint the bottom of a towed boat?
Cadiz	Posted on 2005-03-05 18:40 ET (US) Lately I have seen some boats with painted bottoms, although they are kept on a trailer. What is the reason for this? I would think for the hassle it would be possible to clean the hull once on the trailer instead of having to deal with the paint problem year after year. Can anyone clarify for me why this is necessary?
phil tyson	Posted on 2005-03-05 18:43 ET (US) They may have been docked at one time or another. My Montauk has paint on it from a previous owner who had it on a ramp or tie down.
CapeMayMike	Posted on 2005-03-05 18:59 ET (US) Some keep the boat on a trailer and then slip it around while on vacation, sometimes up to 4 weeks in warm water. I did this with my old boat.
Cadiz	Posted 2005-03-05 21:09 ET (USA) Wouldn't it be cheaper to just clean the hull after four weeks on the water? As I understand it, it shouldn't cause any problems to stay in the water for that long. The reason I'm asking is, being in the market for a boat, I don't really need primer, but many I'm looking for do. I have to decide if it's worth keeping the paint or removing it. I know deleting is a chore, but if this is a brief pain for a long gain, it might be my choice. Does anyone have an idea how much it costs to paint the bottom of a boat left on a trailer and how often?
onde2	Posted on 2005-03-05 21:55 ET (US) 4 weeks in warm water in the Florida Keys will bring you some nice barnacles... 4 weeks in a nice freshwater lake somewhere in the mid-west might bring you kelp... The brown scum I get coming up my brackish channel is usually invisible if you have primer. Since none of my boats have paint on the bottom, I have to scrub the scum off the boat and I will get a noticeable tint in the gelocat due to the tannin in the water if I leave my boat in the water for a week. (this is why I keep my boats on a floating lift instead of in the water...) If the primer was applied correctly, the primer coat is likely a streaky gelcoat, which is difficult to return to a presentable finish after the primer is removed. Soda blasting may work better than other methods, but I doubt it would look like my boat that didn't have the bottom painted.
mantimonts	posted 2005-03-05 21:58 ET (USA) There is endless discussion on this topic. I spoke to Mr. Bennett at the Boston Whaler last fall, and osmotic blisters can appear on your gelcoat helmet after a day, a week, or three weeks, or all summer, or never. It's a virtual dice game and see if you're lucky if that bubble attacks your helmet or the next ones. BW has stated that a barrier coat and primer must be applied if the ship remains in the water. I keep mine in cool, cool Lake Michigan water, and was even told recoating is recommended. I have an estimate of 1150.00 plus a starter strip for my 170. Refinish is every two or three years at 240.00 per coat. This coating is with VC17 Teflon applied with sandpaper between all layers and the final finish is a regatta finish as applied by the local marina to regatta sailboats. I'll get out of the way this spring as soon as it gets above 30 degrees at night here.
cauldron	Posted on 2005-04-05 10:28 am ET (US) Be careful, many people will paint the bottom of a hull to cover up the not-so-good-looking fiberglass repair. It's easy to say that she sat on a slide. If you're looking for used boats, make sure the hull is dry and clean so you can look for a tell-tale patch.
pglein	Posted 4/5/2005 at 7:07 PM m. ET (US) There are many reasons why a person would do this. First being the most obvious: that you are wrong that it is always towed. For example, my boat may seem like a trailer queen to some, but it spends a good three straight months on the water in the summer. The rest of the year, he comes back and leaves. And here in the Northwest, all you have to do is have your boat in the water on a day of the year when the barnacles spawn to wish you had the bottom painted. Another reason is that once you've applied the primer, you'll need to keep doing it. A previous owner may have had a good reason to paint the hull and now, since the gel coat has worn away from previous paint prep and maintenance, it needs to be kept painted for a current appearance. I would never assume that just because a boat has paint on the bottom means there are shoddy or shoddy repairs lurking below. Any patches or repairs must be visible through the paint. If not, that means it was done correctly and shouldn't be a concern. It is practically impossible to use a boat for more than a few years without having to do some type of repair. Also, it can really depend on the type of paint being used. Peeling paint (which we use here in the Northwest on trailered boats) can be easily removed with the use of a pressure washer and a little patience. A more permanent paint (such as Interlux Mircon CSC) cannot be removed without a lot of work and sanding. Of course, the topic of bubbles has already been mentioned. Personally, I will always keep the bottom paint on my boats. Looks good and protects my investment. Leaving the butt unpainted is like leaving the car without wax. Of course, many people do this, but over time, a lack of proper maintenance becomes apparent. Some of the figures they are publishing seem outrageous. I spent $100 on a 1 gallon can of Interlux Bottomkote and no more than 4 hours of my time over several days painting my hull. Hull paint lasts two to three years, and the can still has enough for four or five more applications. So for $100 I'm covered for the next decade.
stefano	Posted on 2005-05-05 10:27 AM ET (US) I live on a canal in Florida, but I'm not allowed on it, so I usually leave my boat for a week tops, then take it out. The ramp is only a mile away. Had to leave the boat for almost 3 weeks when I had my roof refinished - and when I took it off I really wanted to cry - nasty brown background - lol - spent all Sunday cleaning with Mary Kate - a few stains but nothing major - my question is that my neighbor said he had painted the bottom of the roof on the boat several years ago, then decided to remove it and said it looked like new, like the shipyard had taken a pressure washer and sprayed it down. Was that the Sloughing painting he mentioned? Any downside to doing this: If it's easy to get away with it, what's the downside?
Eric Seles	Posted on 2005-05-05 10:41 AM ET (US) I trailer my boat all the time, but every summer I leave my boat for 2-3 weeks in the warm salty waters of the Spanish Mediterranean. I don't have any bottom paint, but I always have an amazing job cleaning up the little barnacles when my vacation is over. Before leaving her in the water I always wax the hull with Starbrite Marine Wax with Teflon. If it wasn't for that, I'm sure I would never clean it the way it should. I am now seriously considering painting the bottom of my hull as I'd rather spend my precious time in the water than cleaning the barnacles and brown spots off my hull. erik
BOB KEMMLER J.R.	Posted 6/5/2005 22:07 ET (US) I find myself in the same situation in my search for a Mischeif. Years ago, I was under the impression that all ships should have a painted bottom. Of course I was raised by someone who knew what the hell he was talking about. has a lot to do with it, or maybe they buy the boat with faded bottom paint and find it looks better with fresh bottom paint (even if they trailer it), etc. A red mischief with black paint in the background is just ugly in my opinion. I hear they have a "running" underpaint, which is supposed to be smoother when run through water than standard paints, but that's not possible. and the search continues
Sheila	Posted on 2005-07-05 01:01 AM ET (US) Bob, have you seen the supposed Mischief that just appeared on the Marketplace? The theme is something about "ski boat".