Bottom paint on Aluminum Crestliner

Prof T

Cadet
Joined
Dec 11, 2022
Messages
6
I’ve got a 2016 Commander with a painted bottom that lives at the dock for 8 months. What a mess when I pulled it. Does anybody have experience with bottom paint on aluminum boats? I wouldn’t completely remove the factory paint, just scuff it so the bottom paint bites.

My glass boat has been painted and it cleans up a lot easier.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
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49,342
with any boat

40-80 grit to scuff the surface
barrier coat (2 layers)
bottom coat (3 layers)
 

Chris1956

Supreme Mariner
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Mar 25, 2004
Messages
27,807
Aluminum hulls require special antifouling paint. If you use a antifouling paint intended for fiberglass, it usually contains copper. Copper plus aluminum makes a battery that dissolves the aluminum.
 

airshot

Vice Admiral
Joined
Jul 22, 2008
Messages
5,023
Painted hulls clean quite easily without fouling paint. Just pull the boat out once per month and give it a good cleaning. I wouldn't take a chance with antifouling paint !! It can be sucessfull with proper preparation and application, but if it isn't done correctly.....to bad !!
I have found a nice gloss paint finnish cleans pretty easy, just don't let it go for so long....
 

FunInDuhSun

Chief Petty Officer
Joined
Apr 25, 2010
Messages
472
Chris is correct- aluminum hulls absolutely require a different coating, especially in salt or brackish water. To do it right, all the old paint has to come off before the proper stuff is applied. I’m sure a boating retailer can help with the specifics. Another thing to consider is adding a galvanic isolator. My slip neighbor has a 32’ Marinette and he keeps an eye on his isolator- it has a gauge telling him how well it’s working.
 

SilentSailor

Recruit
Joined
Jan 16, 2023
Messages
2
Chris is correct- aluminum hulls absolutely require a different coating, especially in salt or brackish water. To do it right, all the old paint has to come off before the proper stuff is applied. I’m sure a boating retailer can help with the specifics. Another thing to consider is adding a galvanic isolator. My slip neighbor has a 32’ Marinette and he keeps an eye on his isolator- it has a gauge telling him how well it’s working.
I agree with you! The galvanic isolator is a must-have! A galvanic isolator is an electronic device on a boat that helps protect against the corrosion of metal parts caused by stray electrical current in the water. It works by allowing direct current (DC) to flow from the outside of the vessel to the positive terminal, while blocking reverse DC from flowing from inside the vessel to the outside. It is very important to not be confused with the anodes - they are totally different but would serve a similar role..
 

Chris1956

Supreme Mariner
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Mar 25, 2004
Messages
27,807
One of the antifouling paints for aluminum hulls is Trilux. Reading the label makes me think the barrier paint coating is extremely important to protect the hull from the A-F paint. I would follow the directions exactly.
 

SilentSailor

Recruit
Joined
Jan 16, 2023
Messages
2
One of the antifouling paints for aluminum hulls is Trilux. Reading the label makes me think the barrier paint coating is extremely important to protect the hull from the A-F paint. I would follow the directions exactly.
Trilux is now discontinued and no longer sold by chandleries! I would replace it with the Seajet 034... or maybe another hard antifoul.
 
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