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Bottom Painting

letsrock

Member
"I am quite new to the boating world. I just upgrade to a 24 footer this year and the boat is in need of bottom painting. My question is since I do not dock it and I trailer it, is there any urgency to paint the bottom?"
 
"Not only is there no urgency,

"Not only is there no urgency, there is no reason. Unless you are keeping the boat in for weeks at a time, there is no reason for antifoul."
 
Just as a follow up. The boat

Just as a follow up. The boat had previously been bottom painted and now its flaking and peeling. What is the best way to get that paint off? Power washer? Scaper? Is it possible to get it all off or does the paint get absorbed into the hull?
 
"The easiest way is to write a

"The easiest way is to write a check. Soda blasting is very effective at removing bottom paint but you will need to hire a contractor to do that. If you want to do it yourself you can sand it off, remove it with paint remover, or simply leave it there. It does not absorb into the hull. If it is ablative it will eventually all dissolve leaving only the primer. If is is non-ablative, it will continue to flake and peel, but will still be noticeable.

Have fun,
Rick"
 
"Just let it flake off on its

"Just let it flake off on its own. From my experience with boats running under 30 mph (cruise speed), rough bottom paint is not a significant drag factor.

Jeff"
 
"Thanks guys, now I just have

"Thanks guys, now I just have to convince my wife that she will need to deal with the way it looks until it all flakes off...LOL"
 
"If by chance you are in fresh

"If by chance you are in fresh water...no bottom paint needed ...actually wish it was not there.Just more expense and work...ask any boater you see with a sander in their hand,paint in their hair and stones stuck to their back...Todd"
 
If the boat is brand new and s

If the boat is brand new and still as the glas coat on the bottom (shiny stuff) does that need to be sanded off before the bottom is painted? Thank you.
 
not sanded off but dewaxed and

not sanded off but dewaxed and roughed up a bit.

best thing to do is read the paint maker's directions and follow them to the letter
 
"most people put on 2 coats of

"most people put on 2 coats of paint, a barrier coat, keeps hull from blistering and is usually a light color, then an anti fouling paint coat that is darker, when the lighter barrier coat starts to show you need to repaint the anti fouling coat.

fresh water boats that are moored should be painted to prevent hull blistering.proper anodes and cathode protection also.

trailer boats not needed, there is an acid that will remove the anti fouling paint but I would just let nature take its course if it was me,soda blasting is great also, but like said you better know what your doing."
 
"From what I understand, to do

"From what I understand, to do a good paint job on the bottom hull, you first need to sand off the layer of gelcoat. Bottom paint doesnt stick to gell coat very well (which may be why yours if flaking). Another reason may be that the incorrect bottom paint was used.
There is bottom paint that is made to keep the boat in the water the entire time, and a different variety which is trailable (meaning it wont dry up and flake when out of the water for a period of time).

I would repaint. (But I also like to have a nice looking boat, even when on the trailer)

Scrape and sand till it is smothe enough for you (80% of the way paint looks is due to the prep job). Then paint on another coat. A Boat your size should not take more than a gallon (about $200).

I suggest using something like Micron CSC.

From Website:
Micron CSC is an great multi-season Ablative bottom paint with a copper-copolymer formula to provide a controlled release of antifouling biocide at the paint surface. The longevity of the coating depends on the amount of paint applied. Retains effectiveness even when the boat is removed from the water for extended periods (winter storage, for example). To reactivate come springtime, use a stiff brush or powerwash lightly.


Thats my novice opinion anyway."
 
"Ok, listen, as Rick said if t

"Ok, listen, as Rick said if the boat is used in fresh and trailered there is no need to bottom paint because the boat's not in the water long enough to accumulate growth. No barnacle problem either.
As MakoMark said, if a new boat is to be bottom painted it must first be dewaxed. That's because a wax is used as a parting agent so the hull will come out of the mold. You in NO WAY sand off the gelcoat. If you do that, first you be at it for a month ansd secondly you be exposing the substrate or laminate underneath wich is what the gelcoat is supposed to protect.Dewaxed & scuffed to give it some "tooth". Followed by a sandless primer coat not a barrier coat. A barrier coat is an epoxy or Vinylester coating that is applied to inhibit water absorption through older gelcoat or after blister repairs. It's time consuming and a bit expensive. Just about all newer boats don't need this as most of them use a vinylester layer behind the gelcoat in the first layup.
Now, if you've decided to go with an ablative paint such as Micron or Petits' Ultima, you first put on a coat of a contrasting color, over the primer, followed by two coats of the color of choice. Doesn't matter if it's lighter or darker. The reasoning is that when you start to see the contrast color you know it's time for a touch up or repaint. Most high quality ablatives are multi-seasonal and are of course meant to wear away with use. Most "hard" paints do not wear away and should be reapplied each season unless stated it will go more than one season.
There's also the waterbased paint such as Aqua-Gard but the procedures are pretty much the same.
Hope this helps some of you who were unsure."
 
The boat is brand new with no

The boat is brand new with no bottom paint as of yet. It has been sitting in the water to get a water line so it can be bottom painted. So then what are the steps. 1. 2. 3.
Thanks
 
"Sorry for the confusion, I d

"Sorry for the confusion, I did not mean to sand off the entire gel coat. Just a very thin uppper layer of it. Paint doesnt stick to shiny gelcoat, but it will if it has been sanded. I also used acetone to clean all the particles so that it became a nice, clean dry surface.

I have heard that they do make chemicals for "Sandless" bottom preperation, you can probably google that.

In my experience, when i painted a new hull of my last boat, I did a great sand job up until the very end (it get tireing) in the aft portion of the boat, i did more of a light sanding then a good sanding. I did end up with flakes but only in that area. The next season, i resanded that area and did a better job, and only lightly sanded the rest of the bottom paint. Never had flaking problems again."
 
"M Clarke,

1) lightly s


"M Clarke,

1) lightly sand gel coat to prepare painting
2) Select paint (you can put on different layers, but check with vendor of choice for which they recommend.
3) paint bottom
4) repeat each year or as needed.


Note, if you have other than fiberglass, you may look into painting them wiht other types of paint. For example, in my outboard, i obtained a certain paint for the aluminum engine mount as the bottom of it was in the water level too. This was paint that had to be done every 6 months, otherwise, regular bottom paint lasted 2.


I also found a significant difference with using propspeed paint on the prop. I plan on painting all the running gear next time to see how long it will keep growth to a minimum on the running gear.

Anyone else ever propspeed all running gear???"
 
"Soda Blasting at a HIGH press

"Soda Blasting at a HIGH pressure over 1500 psi should be done by professionals...however, my the bottom of my vessel was prepared and then primed with a bonding primer and then two thin coats of Hard Ablative (Seahawk). It lasted three years in the harsh waters of Floirda Gulf Coast and just now started to fade..and at last haul out, still had very little barnacles Its been in water since last October in mid-Chesapeake Bay.
area.

I have a KEW professional pressure sprayer at 1000psi. It has an attachment and I purchased silicon crystal sand blasting media...it scratched the coat perfectly with very little sanding afterwards. If sanding required, I used 60-80 grit on a variable speed 5" disk palm sander (with vacuum attachment to shop vac) and now its smooth as baby's butt. In my area, sailboaters swear by Petit's "Trinidad SR" hard abaltive epoxy with bio additive. I'll be set for another 3+ years. I like the hard ablative since there is no repainitng when you haul out the boat and wash down of the hull is a snap. THAT"S MY STORY. There are good epoxy paints out there for trailering boats....Interlux, Petit, SeaHawk are just to name a few. GLuck."
 
"Regarding painting of the und

"Regarding painting of the undergear. I use Petit's two part Metal Primer. Put one coat on and let dry completely.....apply second thin coat and just when about dry...put on one coat of hard ablative bottom paint for shafts, gear, rudders, trim tabs adn thru hull fittings. Ain't gonna git none of dem barnaculs to stick on that for couple years!!!! GLuck"
 
"Hi,

For what its worth i h


"Hi,

For what its worth i hate bottom paint. I work on boats for a living and despise it. ( and working on boats that use it )

Bottom paint on a fiberglass boat is the quickest way to de-value an otherwise good boat. If it's wood its necessary, otherwise- in my opinion it's a bad idea.

As a marine mechanic, none of my boats ever get bottom paint,they get acid baths,scrubbing and elbow grease, and a buff when needed.

I use On-Off Hull and Bottom Cleaner, it works awesome.



http://www.jamestowndistributors.com/userportal/show_product.do?pid=2339&familyN ame=On-Off+Hull+and+Bottom+Cleaner

Course, you know what they say,opinions are like a-holes :)"
 
I've read all of this thread, but I have a different question. Please re-post it if it's in the wrong place.
The boat I just bought has some small punctures in the hull, small like dime size. It also has the gel coat worn off on the spline (?) of the bow. It's 18', trailered. Do I fill the holes with epoxy, and then paint the whole thing? Or take it to a nearby boat yard and have them take care of it (painting the bottom, etc.) If the boat yard is going to do the work, what kind of $$ should I expect to pay?

Thanks.
 
I will assume you are talking about a fiberglass hull.

The small holes and missing gel coat can/will let water/moisture into the fiberglass layers.

Contrary to what the boat companies would have you believe, fiberglass will (rot) just like wood if it gets and stays wet. The layers of fiberglass can delaminate. Also, many fiberglass boats are not 100% fiberglass. The (inner core) is often plywood or balsa wood (recent construction has replaced this with other materials which is reflected in the higher cost), so if there is some wood core it can rot inside the fiberglass - not a good thing.

Patching holes and repairing the gel coat is not rocket science but it is a messy, time consuming job. There are a number of products on the market that you can use for the repairs.

To see if you are up to the job yourself I would suggest you get ahold of the small booklet produced by WEST System called "fiberglass boat repair and maintenance". It's about 90 pages and sells for somewhat less than 5 bucks (available at West Marine or other vendors that carry West System products).

It has a chapters on repairing "damaged skins" and "core related damage".

Gel Coat is not like regular paint and is integral in protecting the fiberglass, so in this particular case I think I would tend to 1) address the holes with either epoxy (West system product or one of the various others - EAST, MAS, System 3 etc) or a polyester resin product (similar to automotive products like Bondo) and then 2) sand and repaint the entire bottom and other areas of gel coat damage with a non-anti-fouling paint (such as VC performance epoxy by Interlux).

To have a yard or boat shop undertake what needs to be done I would expect your quotes to start in the 2K range (without seeing all that needs to be done) and if there is any rot in the hull, the price could skyrocket from there.
 
THANK YOU!! The information you posted is exactly what I was looking for. I will contact some boat repair facilities and get someone working on it ASAP.

Arden
 
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