Removing old antifouling applying new gelcoat?

[HeelBoy]

The unfortunate fact is that my trailer sailer will never be on the water for more than 5 days at a time. If I get extremely lucky, maybe I can take a 2 week trip in the next half decade some time. A simple rag and hose should keep the Great-Lakes the critters off.

So, this winter it’s time for bottom paint, and if I had a magic wand, I’d wipe away the blue stuff and just have a smooth gelcoat. The trailer bunks show evidence of rubbing the antifouling off, which doesn't seem $ustainable. It’s within my ability to got apply new gelcoat, but I feel like there are some gaps in my reading. It's all below the waterline, so resilience is more important than anesthetics.

My gelcoat doesn’t show evidence of being bad (may change as I expose more of it), and everything I read about gelcoat projects is geared toward removing awful gelcoat first. Can new gelcoat adhere to old if I scuff it up? The theory is to roller-on 2 or 3 new coats, then buff/shine it all. The keel will be out and I’ll be wanting to get up in there, too.

Are there pitfalls to a smooth belly that I'm not seeing?
Any reasons that smooth gelcoat won't last a few decades like it has elsewhere on the boat?

Thanks for your time.

 

[dlochner]

Why? Your gelcoat is probably fine.

If the boat spends most of its life on a trailer, there is no need for antifouling paint, especially on the Great Lakes. It takes more than a few days for the growth to start. Leave the current paint on and let it ablate off. Invest in a small electric power washer and when you come home power wash the bottom. You will be fine.

Boats that live in the water all season benefit from anti-fouling. The usually procedure is to apply several epoxy based barrier coats, like Interlux 2000 and then a couple of coats of antifouling.

On the Great Lakes the primary problem is slime and algae, these will wash off with a power washer if it is washed within a day. We don't have barnacles and zebra mussel come right off with the power washer and unlike barnacles do not leave any residue.

 

[HeelBoy]

We don't have barnacles....

Funny you should mention that, I do. lol
The boat has been in Ohio for 3 years, but came from the east coast. There are barnacles on the underside, where the trailer interferes with scrubbing. I am guessing there will be fossilized life in the keel locker, too.

 

[dlochner]

Funny you should mention that, I do. lol
The boat has been in Ohio for 3 years, but came from the east coast. There are barnacles on the underside, where the trailer interferes with scrubbing. I am guessing there will be fossilized life in the keel locker, too.

Lift the boat off the trailer by blocking it up. Take a metal drywall taping knife and scrape the suckers off. They will come right off, but will leave a little white ring. If that ring bothers you get some Mary Kate On-Off and clean them up or use some Muriatic Acid the rings will dissolve.

In the centerboard trunk, do the same, scrape as high as you can get and forget the rest, they aren't hurting anything.

Go sailing or at this time of the year, dream of sailing.

 

[Leeward Rail]

f I had a magic wand, I’d wipe away the blue stuff and just have a smooth gelcoat. The trailer bunks show evidence of rubbing the antifouling off, which doesn't seem $ustainable

The paint is likely ablative antifouling. It is supposed to rub off.

Follow @dlochner advice and you will be fine.

 

[rgranger]

If you really want to get off the blue stuff... spray it with Easy Off oven cleaner, let it dry and then pressure wash. It will strip right off...

As for blocking off the boat to get the barnicles under the trailer slides.... lower your tongue all the way, put a picnic table or a few sturdy saw horses under the transom and then lift the tongue with the trailer jack. That will give you about 3" to get under the trailer pads. Make sure you chock both sides of your trailer wheels.

 

[jssailem]

@dlochner has given you the recipe. If you want to make the process easy get the boat into a shelter. Put down a coupe of sawhorses and flip the boat over exposing the bottom. Now you can work standing up not on your back looking up. If you are aiming for a pristine new looking boat, you can remove the paint with a sander down to the gelcoat beneath the paint.

Andy at Boatworks Today did that very project to a 12ft dinghy sailor.

I think this is the first in this series on this small boat refurbish. They are from last year.

 

[NYSail]

If you really want to get off the blue stuff... spray it with Easy Off oven cleaner, let it dry and then pressure wash. It will strip right off...

As for blocking off the boat to get the barnicles under the trailer slides.... lower your tongue all the way, put a picnic table or a few sturdy saw horses under the transom and then lift the tongue with the traile jack. That will give you about 3" to get under the trailer pads. Make sure you chock both sides of your trailer wheels.

I never heard using Easy Off........ Doesn't damage barrier / gel coats?

Greg

 

[HeelBoy]

The paint is likely ablative antifouling. It is supposed to rub off.

Follow @dlochner advice and you will be fine.

lol True, however it's supposed to ablate off over the course of years. Losing a few mils every time it goes on/off the trailer cuts into that lifespan in the area of the bunks.

@dlochner I'm also interested in the idea of chemical stripping, provided my back yard doesn't become a superfund site. lol

 

[Leeward Rail]

it's supposed to ablate off over the course of years

And it does. Do you realize that many antifouling paints are useless after being out of the water too long?

Losing a few mils every time it goes on/off the trailer cuts into that lifespan in the area of the bunks.

Same thing happens on non trailerable boats with support pads.

If you are concerned about a tiny bit of paint rubbing off on the bunks or pads each year, you are in the wrong sport.

Common practice is to touch up the antifouling as needed. If you have single season paint, that means annual anti fouling paint jobs.

Doesn't matter in your case. Your boat won't be in the water long enough to need it. Just pressure wash it and be done with it.

I'm also interested in the idea of chemical stripping....

Why bother? Any speed difference will be negligible.. If you don't plan on repainting the hull, it's a make work project. unless you need to remove that antifouling to repair the hull

 

[dlochner]

lol True, however it's supposed to ablate off over the course of years. Losing a few mils every time it goes on/off the trailer cuts into that lifespan in the area of the bunks.

@dlochner I'm also interested in the idea of chemical stripping, provided my back yard doesn't become a superfund site. lol

The pressure washer will take off a lot of the paint. You can also take it to a DIY car wash. Those pressure washers are stronger and will take off most of the paint.

I doubt the fish in Lake Erie are sufficiently sophisticated to object to a splotchy bottom. Erie is not noted for haute couture.

 

[HeelBoy]

I doubt the fish in Lake Erie are sufficiently sophisticated to object to a splotchy bottom. Erie is not noted for haute couture.

The fish in Lake Erie can't see more than a few feet, explains the popularity of sparkly bowling-ball finishes on boats.

I chuckled a bit at the concept of this beeing a make-work job.... everything about sailing and boat ownership is a make-work job. lol We pick the superfluous work we want to do based on what satisfaction we'll get from the result. If you think I'm wasting labor now, wait until you see the mahogany I'm going to put in this $3900 boat! I love carpentry, thus I love the work. Painting... still on the fence with that one. lol

 

[rgranger]

I never heard using Easy Off........ Doesn't damage barrier / gel coats?

Greg

I used to post on here a receipe for homemade peel away. YOu take a 5lb bag of garden lime, two cups of lye and put it in a 5 gallon PVC bucket. Add just enough water to get a melted peaunut butter consistancy and then roll that on the bottom paint... the garden lime is there just to add a paste that helps hold the potassium hydroxide (lye) to the paint. If it is hot and dry where you live, you may need to cover it with plastic sheeting so it does not dry out before it is done working... some receipes also add glycerin to keep it moist.... a 10lb bag of sugar will also do the same trick but if you have ants or bees around that might not be a good idea. The ingredients are so cheap I'd skip adding sugars and/or coating with plastic sheets and just do it more than once if some of the paint does not come off the first time. Less mess and hassel that way.

Easy off is also just a very strong base, suspended in some binders to help hold it on the surface you are using. But to do an entire boat it will cost you a lot more. A can of easy off is $5 and you will probably need 20 of them. The entire 5 gallon PVC bucket approach is only $15. If you are going to do the entire boat, the PVC bucket way is much less expensive. I've done this a dozen times.... almost all of the paint will sluff off in big sheets... and for some reason there is always one or two spots that won't come off ... so I put a little citrus strip on those spots. Nice smooth bottom without sanding off any gel coat.

 

[dlochner]

Out of curiosity, what size boat is this? Trailer sailors come in all sizes from 10' to 25' or so.

 

[HeelBoy]

Out of curiosity, what size boat is this? Trailer sailors come in all sizes from 10' to 25' or so.

Nuts, I thought I'd mentioned this but I don't see it. Macgregor 25.

 

[Leeward Rail]

almost all of the paint will sluff off in big sheets...

Fantastic info. Never seen that recipe before.
What have you used for ground pollution protection? More and more storage yards care about that now.

 

[rgranger]

I did this in my back yard.
Put down an old sheet to act like a filter. The chips mostly ended up in the sheet.

 

[sesmith]

I used to post on here a receipe for homemade peel away. YOu take a 5lb bag of garden lime, two cups of lye and put it in a 5 gallon PVC bucket. Add just enough water to get a melted peaunut butter consistancy and then roll that on the bottom paint... the garden lime is there just to add a paste that helps hold the potassium hydroxide (lye) to the paint. If it is hot and dry where you live, you may need to cover it with plastic sheeting so it does not dry out before it is done working... some receipes also add glycerin to keep it moist.... a 10lb bag of sugar will also do the same trick but if you have ants or bees around that might not be a good idea. The ingredients are so cheap I'd skip adding sugars and/or coating with plastic sheets and just do it more than once if some of the paint does not come off the first time. Less mess and hassel that way.

Easy off is also just a very strong base, suspended in some binders to help hold it on the surface you are using. But to do an entire boat it will cost you a lot more. A can of easy off is $5 and you will probably need 20 of them. The entire 5 gallon PVC bucket approach is only $15. If you are going to do the entire boat, the PVC bucket way is much less expensive. I've done this a dozen times.... almost all of the paint will sluff off in big sheets... and for some reason there is always one or two spots that won't come off ... so I put a little citrus strip on those spots. Nice smooth bottom without sanding off any gel coat.

Nice idea. Will it take off VC17 ? If we ever go to salt water I might give this a try if it will.

 

[dlochner]

Nice idea. Will it take off VC17 ? If we ever go to salt water I might give this a try if it will.

Nope. The only way to remove VC 17 is with a sander and aggressive sandpaper. Been there, done that.

 

[sesmith]

Was afraid that would be the answer. Good thing we're in no hurry to leave the Great Lakes then.