Paint on a steel boat

[Yorksafloat]

The paint on my hull (Awlgrip) is looking rather "experienced."* Is there a rule of thumb about how long a paint job on a steel boat should last?* If I re-paint, are there other brands that work better on steel than Awlgrip (or perhaps as good but for less cost)?
Thanks!

Jim
M/V Antipodes

 

[sunchaser]

Awlgrip is the benchmark but how it is applied and surface prep rules the day no matter whose brand. I've heard good things about Sterling. I've seen many vessels with Awlgrip approaching 10 years and they look fine. A black or dark hull in a hot climate can cause some paints to age more quickly. I once had Awlgrip on a wood hull and it was perfect after 5 years when I sold the boat. Some new builds skip the gelcoat and go straight to Awlgrip. Where is your MV located and is it undercover or in the open?

 

[Yorksafloat]

We're located in Ensenada Mexico and the boat is in the open.* I think the surface prep issue is the problem.* But there is also a fair amount of oxidation.* Rust is very hard to keep ahead of since I think the initial epoxy coat was not done properly.*

 

[LarryW]

Sounds like the barriercoat isn't thick enough. If it were mine I'd take a sander and see how many coats they use before topcoating it. When you hit it with a decent size sander/grinder you should be able to see how many coats are there. I hear the labor rate where you are is really good, wish I had my boat over there. As it is I've been putting off the sandblasting untill I can find a youth formula. I have access to all the equipment just need to save up the money for the black beauty and energy for the actual work.

The life of a steel boat is determined by its barrier coat. The more the better. Bar Rust 235 is always on my boat. I use it where ever I take it to bare metal, 2 coats with at least 1 top coat.

 

[Yorksafloat]

Larry,
Thanks for the reply.* I know for a fact that the bottom coat was "inadequate" so I am pretty sure the main hull and deck wasn't done right either.* Any little nick starts rusting.* There are also some "hidden" areas where the welds weren't ground smooth and the rough areas are a magnet for rust and when it gets going it is damnably tough to deal with.*
I suspect some sandblasting and grinding is in my near future....* At least the labor rates down here aren't too heinous.
Jim

 

[FF]

Sherwin Williams and all the big boys formulate paint for SHIPS.

There all steel, and really expensive to have out of service for a paint job.

Their Specs are on line , but all begin with ,media Blast to "water white" or something similar with the specifications for the blasting in an international standard.

The newest Epoxy surface coatings , BOTH inside and out , can give steel a long service life.

Most steel boats will have simple to remove interiors to facilitate the process.

FF

 

[LarryW]

If the outside of the hull is lacking then I would make an effort to look at as much of the inside of the hull as possible. Take a light and look at as many of the hidden areas under the floor, around and under holding, water and fuel tanks. Any dirt or even scraps of metal, don't laugh I found it in my boat, will hold moisture and cause rust which you won't see until you have a leak. Finding it now instead of 34 years later, as in my case, will cause you less problems in the future. Replacing steel plate in the bottom is no fun and unless you have access to a good welder who knows what he's doing expensive. So take some time and do a really thorogh search of all spaces and know what you have.

 

[FF]

For folks doing a newbuild , it is far better to use flat steel , rather than T section to stiffen areas.

The flat is simple for the blaster to see behind , the T is really really hard to prepair.

Talk to the NA first.