TOPIC: Rustoleum topside -or- bottom paint (opinions plz)

I'm going to paint my 57' MFG with Rustoleum. Doing this since in my opinion it seems like the hull is almost "raw" fiberglass, without any indication of any gelcoat, or any other top coat finish. I have it degreased, 30 second bleached, and generally fully clean and ready to pain,

I know Rustoleum makes topside and bottom paint. I obviously want a smooth a brush job possible. I read somewhere that if you aren't going to leave the boat in the water there really isn't a need to use bottom paint. The boat will be used primarily in salt/brackish water, but stored in the garage or on a lift.. Opinions please on topside - vs- bottom side paint necessity.

I've never really looked at bottom paint before but have noticed it on pontoon boats etc, and it seems like bottom paint isn't smooth; eg almost granular in the look and feel. Am I getting this all wrong?

OK, bottoms are a bit different. If you talk to old flat bottom drag racers they will tell of spraying the bottom with gray lacquer primer and then wet sanding with 320 grit to get best speed. So it turns out the water does not want gloss on a bottom. It wants a bit of a tooth to set up the boundary layer for laminar flow adjacent to the surface. That's why bottom paints are mostly like flats or semi-gloss's at best ...

You want maximum adhesion and durability, gloss is the way to go. It's a more durable "skin".

I prolly would not do a straight brush job. And I did many when working in boat yards in years past. I'd do a technique called Roll & Tip. There are YouTube videos that will show you how.

I use Rustoleum paints among others. I also thin with acetone or MEK and add enamel hardener/catalyst I get at Tractor Supply. Valspar hardener works great on Rustoleum.

BUT, all Rustoleum paints take at least 7 days to get hard enough to use. The longer it cures, the better it gets.

A two-part polyurethane like Interlux Perfection will come out stronger and cure quicker if you can do the higher asking price. Either will Roll & Tip to near a glass smooth finish

Here's a link that might interest you about bottom paint. Since you're not keeping it in the water the Rustoleum will work for you. The roll and tip method works for me sometime. I say that because sometime I will get a beautiful job and the next time it will look like a second grader used their fingers.
www.boatus.com/magazine/2014/april/boat-bottom-paint.asp

Thanks for the pointers. I'll spend some quality youtube time to watch folks through the roll and tip methods. Of course I'll do a little practice on a board to minimize the regrets.

I'm a little confused by your answer, so you think I'd be okay with "topside" paint, even on the hull bottom since it'll be on the lift or a trailer most of the time. I don't mind the wait time for it to cure well; I can afford the downtime with other detailing...

Add enamel hardener to Rusto and it cures harder, quicker and w a higher gloss level. In fact, use Rusto Pro oil enamel, not their topside or marine branded paint.

Great input! Thx- Never looked for hardener before. Guessing any good paint store would have it and the Pro oil enamel? Not a home depot thing is it?

Home depot, Lowes, etc. would have the hardner. It will come in a small pint can and just add some to your paint while you're mixing it up and then add thinner if you want. Rusoleum thins with mineral spirits. After you mix it let it "cook" for about 15 minutes. This helps the chemical reaction...so I'm told.
Here's another link to the small difference between the "bottom" paint and regular. I've always used the regular with HARDNER]ACTIVATOR. Nice thing about that is if for some reason you need to fix up an OOOOPs like a drip or run it can be sanded after 24 hours. Also if you use the Rustoleum gloss white and need to fix a mess you can get one of their rattle can gloss white to patch it. After that fix dries you can polish it with a buffer and it will blend right in. Eliminates the remix etc.
forums.iboats.com/forum/boat-repair-and-restoration/boat-restoration-building-and-hull-repair/534513-is-there-really-a-difference-between-regular-rustoleum-and-marine-topside-rustoleum

Brushed.

Inspiring, really impressive work. Brushed!
I appreciate all this information.
Anyone else who is in the know chime in. I'm all ears.
No really I have huge ears.


Seriously this is helpful.

Even Ace Hardware brand Rust-Stop oil based enamel works.

This is flippin' amazing... Great job!

Great info.
I've seen mentioned in various posts notes along the lines of "if your boat trailered stored, use xxx or yyy paint" I've not been able to find note to suggest paints for boats that are going to stay in the water for 4 to 5 months at a time. Any suggestions?

2-part polyurethanes if they will be sitting in the water for months. Best 'skin' for constant immersion

If that's too difficult due to respirator needs, etc. Next up would be Mono-poxy.