Bottom Coating over old Sharkhide?

tyjy

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New pontoon 2014.

Factory Sharkhide.

All season in "muddy" Mississippi River.

Lots of elbow grease to clean toons even with Sharkhide.

Used medium bristle brush!

Million dollar question:  how much of the exiting Sharkhide was scrubbed off???

Idea: Many years ago we took our aluminum fishing boat to Florida without any bottom paint or other preparation. Stayed in water a month. Was a bear to scrub clean! Second year applied Easy On Bottom Coating by Boat Armor (not many products for "aluminum") prior to the month long stay in the water and it was MUCH easier to clean the bottom.

QUESTIONS:

     We have leftover Easy On and was wondering if it might be a good application prior to launch this year?

     Do you see any problems with applying over the old Sharkhide?

     Do you think there's a better solution or product? (Sharkhide was fine, and no doubt about it saved in labor, but our River is dirtier than most waters!)

(Going to try and post pix)

http://club.benningtonmarine.com/index.php?/gallery/image/5268-winterizing-pontoon-036/
 
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I would look in to a product called AlumaSpray+. It's a biocide anti-fouling spray paint specifically for aluminum hulls. It's made by one of the big bottom-coat companies - Petit or Interlux or something like that. I've seen it on the shelf at West Marine. Probably available lots of places.
 
Not sure if I was clear...I am wondering about this second season of the pontoon boat (not the old fishing boat). Hoping to find an application to make it easier to clean the toons (we only pulled the boat once mid season last year to do the 20 hr maintenance). It seems most forum contributors just reapply Sharkhide every year or two, I am just wondering if SH is strong enough because the Miss. R. is so dirty? (Could pull the boat out more often if need be, but a hassle. We dock in water in a marina all season.)

JeffS: would you still recommend that AlumaSpray+ now that I explained it better? THANK YOU
 
Do whatever makes you happy.
 
You're smarter than me! Would you just keep reapplying SH every year or two? THANKS : )
 
If I were leaving my boat in the Mississippi for months at a time, I'd try to find an ablative bottom paint that didn't harm the aluminum hull. They are also called sloughing bottom paints. I've never had to come up with a solution to this problem, but to answer your question directly...no...I wouldn't expect sharkhide to do what it's not designed to do. Sharkhide is there as an air-barrier to prevent oxidation. Bottom paints are marine-growth barriers that prevent marine growth. Two totally different challenges...in my world...would require two totally different products. But that's just me.
 
JeffS: Thank you so much for your input! As my signature states...we're learning!! I think I never 100% understood the difference between SH and bottom coating so certainly appreciate your help. Thanks again!
 
I'm careful to not tell people what to do. But when people ask me what I personally would do, I'm happy to chime in. So many different personalities on the interwebs and I never know who's who. Just because I do something a certain way doesn't mean anyone else should. Which is why I frame my answers the way I do. And you're very welcome.

Here's some insight into ablative (sloughing) bottom paint that you can stick into your memory bank somewhere way in the back. Ablatives are like pencil graphite. As a pencil glides over paper, graphite comes of in super-thin layers leaving the markings on the paper. Ablative bottom paint is paint that comes off in super-thin layers as the boat moves through the water. If your boat is sitting for a couple of weeks, slime and marine growth will accumulate on your hull. As soon as you get underway, the outer layer of paint sloughs off taking the marine growth with it. You'll leave with the toons all covered in slime. And come back with nothing but the next layer of paint.

Upsides - 

1. Super simple to use.

2. Not toxic to the environment (much).

3. Does not contain copper (copper is used in hard-surface non-ablative coatings to inhibit growth) so it won't promote galvanic corrosion.

4. Relatively inexpensive.

Downsides.

1. Messy as hell.

2. Has to be re-applied every year.

3. Messy as hell.

4. Messy.

5. As hell.
 
I appreciate your responses and completely understand where you're coming from! Also appreciate all the info/first hand knowledge you provide!
 
JeffS you are a great asset to this forum and we appreciate your knowledge and advice so keep your comments coming
 
Keep in mind when looking for copper free antifouling ablative bottom paint some work better in fresh water vs. salt water so that's what you'll want to seek out. Mission Bay is a good paint for fresh water....and make sure it will adhere to Sharkhide. Of course these antifoulants work best with the recommended manufacturers primer. 
 
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