Educate me on Bottom Paint!

[gtochris]

I posted this previously on the resturation section and it disappeared due to the vast amount of other posts.

My boat only has bottom paint because it was in a lake that had some type of growth and everyone did it, (before me), it was never in salt water. As you can see below, it is pealing off.

The "type" on there I dont know, but it will swipe off on your hand or brush if you rub it wet.

I'm VERY confused as to what the difference is in the various types and since I'm NOT using the boat in salt, what can I re-paint the hull with (that is black) and will make it look pretty again and not cost a fortune?


Thanks!

 

[Fireman431]

Re: Educate me on Bottom Paint!

HOW TO PAINT PREVIOUSLY PAINTED BOTTOMS:

The condition of any existing coating is important in order to provide a sound surface for the new antifouling. If the paint is in poor condition, remove it with Interstrip 299E and follow procedure for bare work.

Option A for KNOWN TYPE OF ANTIFOULING PAINT:

Check for compatibility; see compatibility chart on the Original Article link below or Interlux Color Card. If you know what antifouling is currently on your boat, you can quickly determine whether your Interlux paint choice is compatible.

1. Remove all traces of loose paint, dirt, grease and other contamination by wiping with Interlux Special thinner 216. Sand with 80-grit sandpaper. Remove sanding residue.
2. Apply 2 coats of Interlux antifouling.

Option B for UNKNOWN TYPE OF PAINT; PRIME BEFORE PAINTING:

If you do not know what the old antifouling is on your boat, it is still easy. Use Primocon as a tiecoat primer. Then simply overcoat with the Interlux bottom paint of your choice (not compatible with VC 17m, VC 17m Extra, VC Offshore or Baltoplate).

1. Remove any loose, flaking areas with a scraper. Sand with 80-grit sandpaper. Rinse with fresh water and allow to dry before applying the new antifouling. If the old coating is in poor condition it is advisable to remove it. Apply Primocon primer directly to the old antifouling.

Option C UNKNOWN; REMOVE

If the old paint is in poor condition remove it. For removal, we have the easy solution, Interstrip paint remover. It's compatible with your valuable fiberglass hull and can remove several coats of paint in one application. After stripping, you are ready to prime and paint your newly cleaned hull.

 

[gtochris]

Re: Educate me on Bottom Paint!

Thanks so much, I'm printing this off for reference.

I think I am going to follow the option B.

 

[Chris1956]

Re: Educate me on Bottom Paint!

How about choice "D"?

Nothing will stick to peeling paint. You have to get down to either bare fiberglass or sound bottom paint. If you are at bare fiberglass, and you do not need AF protection, you can roll and tip some polyurethane paint made for below the waterline. That will look the best.

If you get to sound bottom paint, most modern bottom paints will be compatable, so no need to prime the surface. Just roll on some new bottom paint. I would recommend an ablative paint if you need AF protection, or any modified epoxy paint is you don't need AF protection.

 

[gtochris]

Re: Educate me on Bottom Paint!

How about choice "D"?

Nothing will stick to peeling paint. You have to get down to either bare fiberglass or sound bottom paint. If you are at bare fiberglass, and you do not need AF protection, you can roll and tip some polyurethane paint made for below the waterline. That will look the best.

If you get to sound bottom paint, most modern bottom paints will be compatable, so no need to prime the surface. Just roll on some new bottom paint. I would recommend an ablative paint if you need AF protection, or any modified epoxy paint is you don't need AF protection.

I was thinking that also, it flakes off every time I pull and wash the boat at this point.. A little light sanding and their might be nothing left!

Any clue as to what "type" of paint I have currently since mine will rub off so easily when wet and what that means for the replacement paint?

 

[Beefer]

Re: Educate me on Bottom Paint!

I'll guess you have 'ablative'. Ablative is designed to wear away, whereas 'hard' doesn't. Ablative is common on the big big boats that never leave the water.

 

[Fireman431]

Re: Educate me on Bottom Paint!

Let's recap...for ANY type of bottom paint:

1) Scrape off loose particles
2) Sand with 80 grit, resand with 200 grit
3) Pressure wash and allow to thouroughly dry
4) 2 coats bottom paint

 

[soggy_feet]

Re: Educate me on Bottom Paint!

Don't forget option 'cheap'

interlux is not cheap.

I painted my hull black with an industrial coal tar epoxy. It was around $200 for 5 gallons. Goes on like roofing tar, hardens like, well, epoxy.

You could float your boat in a vat of acid and it wouldn't touch it.

 

[Chris1956]

Re: Educate me on Bottom Paint!

Actually most bottom paints, (modified epoxy, ablative, the real soft copper for displacement hulls and sailboats) will come off on your hand. There are some hard racing bottom paints which are a little bit harder, but not a lot harder.

if it comes off so easy, it probably makes sense to take it off. Pressure washer and scotchbrite pad? Careful or the PW will take off the gel coat.

 

[TilliamWe]

Re: Educate me on Bottom Paint!

Uumm, unless it's in this primer- "Primocon"- you NEED an epoxy barrier coat before your bottom paint. Bottom paint will NOT prevent blisters, unless it's EPOXY.

 

[smokeonthewater]

Re: Educate me on Bottom Paint!

or option E

take it off and leave it off

clean it off and sand the gellcoat just enough for a satisfactory finish

 

[Chris1956]

Re: Educate me on Bottom Paint!

There is no bottom paint that I know of that will prevent blisters. For bottom paint to work, it must let water leech out the copper in the paint. However, not all hulls are succeptable to blisters. The question is do you feel lucky....

Actually Chris, if the boat was kept in the water already, and doesn't have blisters, it very likely won't develop them now. Priming bare gel coat beforer bottom painting is real smart, as the paint won't fall off in large chunks, like it can do on unprimed hulls.

 

[Thalasso]

Re: Educate me on Bottom Paint!

If you don't have bottyom paint before you put any on apply barrier coat.If you are going with Interlux they will even tell you this. If you call or E-mail interlux with your boat type and length they will get back to you with how much of everything you will need.( barrier coat primer bottom paint)