Bottom painting

[CharlieO.]

1977 Marine Trader 34DC
Took us 2 full gallons to do 2 good coats with just bit left for touch up for where the keel blocking is.
West Marine PCA ablative antifouling paint.

 

[Comodave]

Looks nice.

 

[Barking Sands]

Looking good!

 

[fgarriso]

Your lucky to do it with two gallons, we did our 58 last fall and it took six gallons.

 

[BruceK]

That`s one smooth bottom on a 1977 boat. Great preparation!

 

[Marco Flamingo]

Here's a bottom painting question. I don't think I've ever seen bottom paint on a stainless shaft. Why not? I'm out of the water right now and just painted my rudder (cast bronze with a SS rudder shaft). The paint was almost completely gone off of the rudder. There were "barnacle rings" left from when the divers last cleaned it, meaning that there wasn't enough paint remaining to keep the barnacles at bay. Bottom paint didn't last two years on the rudder blade. But the rudder post was shiny stainless with no sign of ever having growth. Same with the prop shaft, even though there were some little barnacle rings on the prop itself. Is there something about SS that doesn't require a biocide?

 

[rslifkin]

Here's a bottom painting question. I don't think I've ever seen bottom paint on a stainless shaft. Why not? I'm out of the water right now and just painted my rudder (cast bronze with a SS rudder shaft). The paint was almost completely gone off of the rudder. There were "barnacle rings" left from when the divers last cleaned it, meaning that there wasn't enough paint remaining to keep the barnacles at bay. Bottom paint didn't last two years on the rudder blade. But the rudder post was shiny stainless with no sign of ever having growth. Same with the prop shaft, even though there were some little barnacle rings on the prop itself. Is there something about SS that doesn't require a biocide?

SS trim tabs and shafts do get growth in my experience. I've got everything SS below the waterline on my boat cleaned, primed, and painted, shafts included. I'm in fresh water, but it definitely keeps them cleaner and means the powerwash at haulout goes faster and there's less leftover slime, etc. to clean up.

 

[backinblue]

All underwater metals need painting, at least where I am. There are anti-fouling paints specifically for metals that are different than what you'd normally use on a fiberglass hull.

 

[PhilPB]

Here's a bottom painting question. I don't think I've ever seen bottom paint on a stainless shaft. Why not? I'm out of the water right now and just painted my rudder (cast bronze with a SS rudder shaft). The paint was almost completely gone off of the rudder. There were "barnacle rings" left from when the divers last cleaned it, meaning that there wasn't enough paint remaining to keep the barnacles at bay. Bottom paint didn't last two years on the rudder blade. But the rudder post was shiny stainless with no sign of ever having growth. Same with the prop shaft, even though there were some little barnacle rings on the prop itself. Is there something about SS that doesn't require a biocide?

My ss trim tabs and ss shaft are painted. The only places not painted are under the zincs where they are attached

 

[CharlieO.]

Thanks, the bottom was in pretty good shape. we just pressure washed at haulout in the fall and brush cleaned it before painting.

Before we launched last year I had the yard I bought it at paint it. I gave them the ok for 2 gallons and do their best. Their job was definitely more transparent, I could see the red undercoat showing in places after they were done.

The paint can says it would take 2.5 gallons so I bought 3 gallons and now have a full unopened can left over.

 

[Southern Boater]

Here's a bottom painting question. I don't think I've ever seen bottom paint on a stainless shaft. Why not? I'm out of the water right now and just painted my rudder (cast bronze with a SS rudder shaft). The paint was almost completely gone off of the rudder. There were "barnacle rings" left from when the divers last cleaned it, meaning that there wasn't enough paint remaining to keep the barnacles at bay. Bottom paint didn't last two years on the rudder blade. But the rudder post was shiny stainless with no sign of ever having growth. Same with the prop shaft, even though there were some little barnacle rings on the prop itself. Is there something about SS that doesn't require a biocide?

As already mentioned, SS does need painting/protection. Just hauled after two years, but I have been monitoring by diving and looking, I lost all the paint system off my rudders and shaft A brackets due to what I think was over prepping.
I had prepared the props and shafts for Prop Speed and was told to get them as clean as possible, carrying on similarly to the rudders and A brackets, prepping for primer and anti foul paint.
Apparently the surfaces for the rudders and A brackets were too smooth and the primer let go within a few months and I was left with a shiny SS finish which after another six months was covered with juvenile oysters. The surfaces needed abrading to an 80 grit finish I was told later.
I had used an etch primer, Primocon and then three coats of anti foul paint.
The Prop Speed was in perfect condition.

 

[koliver]

There must be someone who knows the science of paint on metals v on FG.
In my experience, using whatever paint I have used on the hull, or nothing, or something different, my hull comes out with only a little slime, while the metals are covered in barnacles, mussels, oysters, and weed.
Over the years (all post the reduction in toxicity mandated for anti fouling) I have tried a number of different things on the metals, sometimes one on the port side with a different one on Stb. Nothing has been effective on the metals. At the same time, I can go 2 or maybe 3 years on the hull with modern paints, but the metals are so bad with hard growth that I need to haul annually.

I see little difference whether the metal is SS, brass or bronze. I get hard growth worse on the struts, which are bronze, but lots on the props (brass?), on the rudders (SS) and on the shafts (SS).

 

[BruceK]

Ablative on the hull but not on the running gear, hard works better there. And on the bits that move, ie shafts and props, Propspeed.
Btw, a marina I talked to recently charges $80-$100 per prop blade. With 2 4 blade props that gets expensive.

 

[backinblue]

Keith, I have the same exact problem on my boat. Haven't solved it yet but I keep trying. I'd be intereted if anyone has actually had this problem and found a solution.