Bottom paint on motors

[GreatWhite23]

Going to be dropping gulfstream into water at the end of month. Won t be pulling her out except for inspection and cleaning. The motor brackets and portion of lower unit sit in the water at full tilt. I am worried about corrosion would bottom paint work for this app??? What would the proper app for this??

 

[georgemjr]

They make an outboard, anti-fouling paint, in a spray can. It comes in black and clear, I don't know about other colors, and the clear isn't exactly clear. It doesn't work for shit, or at least not nearly as well as regular bottom paint, as my motors get significantly more growth, worms, and barnacles than the hull gets. That being said, I use it because regular bottom paint has metal in it and it is supposed be able to cause erosion. I have used regular bottom paint on an old boat/motor figuring I would wear the motor out before it rotted. I never wore the motor out and it never rotted, but the paint did work better than the specialized outdrive paint.

 

[GreatWhite23]

thanks

 

[fishbust]

23,
The anodes will protect you from corrosion. The zinc sacrifices itself before aluminum.
You can bottom paint your motors for marine growth. You just need to use the correct type of anti-fouling paint for aluminum.
I buy Trinidad by the gallon to paint the hull every other year. I have been told by my surveyor I can go 3 years with this stuff. Last time I went 3 years was with VC Offshore but VC is not compatible with other paints and I stripped my last hull to use it. Maybe will try the 3rd year with the Trinidad.
I buy Interlux Trilux 33 for my underwater aluminum and tabs.

 

[DennisG01]

Although I don't use it, friends use Trilux 33 and seem to be happy with it but make sure there is a 1" gap around your bracket as outdrive paint and hull bottom paint shouldn't contact each other. The big thing to watch out for, as stated above, is that you don't use anything with metal (copper is the common metal used) in it since it can cause corrosion on your drive or aluminum bracket. I just picked up this Grady that I have and it will stay in the water for the season. I'm planning on using Pettit Hydrocoat Eco since I can use that on the hull, bracket and lower unit - just makes llife simpler in the future. This paint is copper-free and also water based (great for cleanup!).

 

[seasick]

if you use any copper based paint you are at risk of corrosion of the aluminum motor parts. It's even not advisable to apply copper based bottom paint on the transom where it is in contact with the motor bracket
The clear spray Trilux in my experience, just doesn't work well at all. It may add some protection but you need at least three coats and even then, growth can be an issue.
There are paints specifically designed for outboards. They are not cheap and you need to make sure you follow the directions closely.

 

[fishbust]

if you use any copper based paint you are at risk of corrosion of the aluminum motor parts. It's even not advisable to apply copper based bottom paint on the transom where it is in contact with the motor bracket
The clear spray Trilux in my experience, just doesn't work well at all. It may add some protection but you need at least three coats and even then, growth can be an issue.
There are paints specifically designed for outboards. They are not cheap and you need to make sure you follow the directions closely.

I gave up on aerosol a long time ago.
I buy trilux 33 by the quart for my outboards, lasts a long time.

 

[DennisG01]

I gave up on aerosol a long time ago.
I buy trilux 33 by the quart for my outboards, lasts a long time.

That's what my friends use, too. I believe a few of them had tried the spray-on, but had disappointing results. Happy with the brush-on, though.