Do We Need Bottom Paint?

[thataway]

However, my wife and I plan to haul it to Florida this Covid winter and travel around in salt water for approximately 2 months. I estimate it will be in the water an average of 2 weeks at a time, then trailer to a new location.

A lot of difference between Northern waters and S. Florida Waters. I happen to live just up Perdido Bay from 83GB and also have an 18' CC (Catamaran) fishing boat. It lives on my boat lift or a trailer, except for a period of 5 years when we kept it in the water at Marathon, (Keys) Fl. We have Vivid bottom paint top of the 20 mil of epoxy. We and our neighbors used the boats every day in the Keys. After 4 months in Marathon there was no significant growth on our boat. Several neighbors had gel coated boat, with no bottom paint. These had to pull their boats weekly, pressure wash, and still had some barnacle plates attaching to the unpainted hulls. Basically the cleaning procedure is pressure wash, scrape any barnacles which have adhered, and then use strong acid or calcium resolving chemicals to try and remove the rest of the barnacle foot plate. Nothing stronger than barnacle "glue".

My advice is to bottom paint. There are many factors which go into the value of a used boat--bottom paint or not. I did sail boat ocean racing for many years, where we burnished the bottom paint weekly or sometimes tx a week to have the "fasted bottoms"...

 

[C lectric]

I am going to retract what I said in Post # 12. Up to one or two weeks and then a power wash would Likely be OK. I realized I leave my dinghy, without bottom paint, in the water for a week at a time. Then it is up on the swimgrid out of the water. Never has a problem. I suspect that 2 weeks would be ok also IF you pay attention. Once the little beggars get a grip they can be tough to remove as I have found. Just carefully watch for any signs of growth.

I will also caution about those abrasive scrubby pads. If you mean Scotchbrite be very carefull as you may be removing gelcoat a bit at a time. The white Scotchbrite uses talc powder for the abrasive which is relatively soft and meant for polishing applications.

All the other Scotchbrite pads use silicon carbide which is harder than glass and will take off the gelcoat a bit at a time. For that reason I use Scotchbrite very carefully and minimally aboard. I have several varieties for different purposes so be carefull about its use.

Even the Mr Clean I won't use for the same reason. I have not checked that one for the abrasive type but I ruined a finish by its use on some other wise nice chairs and even had to get rude to stop people from trying to "HELP" on other projects with them.

 

[jgtrucking]

If you do try bottom paint... beware that much on-and-off the trailer is going to wear the ablative paint off at the trailer contact points. In one season a guy I know had worn it totally through. I have a hard paint and until I purchased it was out of the water 6 months of the year (Green Bay, WI) and even though it is nearing it's usable life, has done a good job in the rivers. Can't speak to how FL waters would attack it.

 

[psneeld]

I have to say it once again....it really depends on so many things...one solution or experience is just that.

In some marinas I have stayed...growth is rampant out on the docks in the current where daily turnover nutrient rich water supports it,, while growth is slow, almost not existent in the stagnant, sediment heavy, low light water in the back.

I or anyone else can't guarantee results without detailed info up front... so the harm in trying no paint might be just a good cleanup (less so if attended to in the water) and bottom painting later. But once bottom painted...its a long road back to where one started ....if you even go there.

 

[fstbttms]

If you do try bottom paint... beware that much on-and-off the trailer is going to wear the ablative paint off at the trailer contact points. In one season a guy I know had worn it totally through. I have a hard paint and until I purchased it was out of the water 6 months of the year (Green Bay, WI) and even though it is nearing it's usable life, has done a good job in the rivers. Can't speak to how FL waters would attack it.

Again, most (maybe all) hard paints are rendered inert by exposure to air. This makes them unsuitable for trailered boats, your cold freshwater, short-season experience with them notwithstanding.

 

[RLKramer]

I'm late to this conversation but you mentioned you will be in freshwater. If you are in freshwater and you are only in freshwater for short periods, I would not put bottom paint on your beautiful boat.

I have a boat on Lake Superior from June until October continuously. The scum that grows (lightly) on it comes off with a pressure washer. It is way different than my Florida boat that is in the water 12 months of the year and gets dived (or is it diven?)/bottom cleaned every 3-4 weeks.

The antifouling paint seems overkill for freshwater scum. I think you will regret painting it if you do.

 

[Tangler]

Just an comment...I moored in the Fraser River for 12 years... no bottom paint...a few weeks in the salt and the green slime from the River the s gone and then return to the River sluices off any salty attachments...not an option for many I know but it worked for me

 

[Juggerknot]

While I'm a big fan of ablative paints on my bottom, I am in the water unless hauled for maintenance. Several of my land neighbors are avid fishermen, use their boats regularly and refuse to bottom paint but they are all lift kept and generally unless a long weekend in the Bahamas, they are in and out same day. They run 30 knots too so the bottoms are clean. For your rig and the hull speeds you'll see I'd probably bite the bullet and paint, it will be cheaper in the long run as pressure washing will add up and you will get growth in Florida's tropical waters. Just my 2 cents, nice boat btw, enjoy =)

 

[cabinetman1955]

Paint

Painting took 3to 5 knots off the top end when I did my Boat.

 

[backinblue]

Painting took 3to 5 knots off the top end when I did my Boat.

That seems like a lot. What is your top end speed?

 

[Chrisjs]

I a have a similar but different experience, but I only lost 2.5kt.
Even though I used ablative bottom paint on my 50ft trawler, there were a couple of times when we could not get above 5kt compared to our normal cruise at 7.5kt. Both times it was barnacles and crap on the prop which we also painted with hard antifouling. This was even though the boat was being used regularly. If the boat stays in the water for more than several days at a time, I think your unpainted bottom will soon look a mess even with cleaning and scraping.

 

[Bill V]

When I bought my boat 16 years ago I had years of bottom paint soda blasted off so I could have a total "reset" to a clean bottom. Applied a coat of sealer, then a coat of red hard bottom paint and 3 coats of dark blue ablative paint. I keep my boat in salt water May 1st to late October and have it slung on and off my 3 axle trailer. Stored in my heated shop during winter months. I pressure wash the bottom gently and I am just this year seeing the red hard bottom paint indicating I am due for an application of ablative paint. I will again apply 2-3 coats of ablative for another 15 years or so of a clean bottom.

 

[DarrenCharles]

Bottom Paint Experiment Update.

I decided to bottom paint our boat. I left the vertical surfaces below the waterline unpainted as an experiment because it is an easy area to clean. I found that if I cleaned it once a week, there was no significant build up and easy to clean. However, I would not have wanted to clean the complete bottom side of the boat weekly.