Pontoon Boat & Deck Boat Forum

My pontoon logs have these spots and I have no idea what is causing it. Any one have an idea ?



Thanks
Randy

Do you trailer? Looks like road rash

Used in salt water? Stray electrical current? my pontoon spent 20+ summers in a fresh water lake and don't have any pitting like that.

Mineral deposits?

Looks a lot like my salt water deposits, but that dosen't make sense for you.

Hard to tell from the pic. Are they spots or pits?

Heavy mineral deposits in the water, the grade of aluminum used in making the toons?

Same exact spots I get on my boat when it sits in my slip, down at LotO. Its electrolysis. Somewhere current is being released into the water. You should see mine after being in the water for straight 6 weeks. I turn my batteries off completely, when I'm done running. It could be coming from another boat, or our dockhouse, I wish I knew. After the Electrocutions in the water at our lake, this year, the condo association had the boathouses tested and they were all fine. I will be re-polishing the bottom this fall, (All the Sharkhide in the world won't stop that) and buying a lift for the slip real soon. I'll get a pic for you when I get out to the boat, later. So we can compare our boats. Its not a fault of the Premier, because it happenend to my Manitou, as well. Same exact damage. Stripped off the Sharkhide, wetsanded with 600 grit, it smoothens right out. Then polished and re-Sharkhided the Manitou, took me about 3 hours, to fix that one. The Premier won't be as bad, because I just go down to the trailer bunks, on it. But still, its time, off the water when I can be on it.

Loyd,

It's not road rash cause I have a TowTector on my truck.

rancherlee,

Fresh water only.

rancherlee,

Not mineral deposits because I tried CLR and Lime Away and they didn't remove the spots.

Texoma Toon,

They are spots and not pitted.

Bryden24shp,

I was thinking as you are that's it's some sort of electrolysis.


Would that be a bad ground from the motor or on one of the electronics in the boat ? Our boat is trailed and does not sit in a boat slip.

EDIT: I just ordered some anodes for both the motor and the pontoon logs. Hope they work.

Thanks
Randy

You really need a current path for electrolysis. Start from there and see if that makes sense. It still might just be the water. What is the pH of the lake?

Take a bottle to a swimming pool place and tell them you want the works. They usually test water for free. Get the total dissolved solids pH and alkalinity at the least, maybe metals or whatever else you can trick them into doing.

GregF,

I don't believe the lake here is causing it because our old pontoon never did it.

My new Bennington has the streaks at the top of the toons like in the picture, but no pitting below. It was manufactured the first of May, and has never been in the water but twice.

I'm going to hand wash that boat good before putting Sharkhide on it. I may have to use aluminum polish to get the streaks off--then wash it down with lacquer thinner.

My two local boat dealerships' parts guys had never heard of Sharkhide. All they knew about was muriatic acid cleaners. I found a quart of Sharkhide at a dealership 1/2 hour north @ $41.50--great buy.

It certainly looks like some kind of water corrosion because it is above and below the water line. Electrolysis would only be below the water line or right at it.

There are lots of alloys of aluminum. This one seems susceptible to whatever is doing this.

My boat has always been painted and I think that solves a lot of problems even if it not real bottom paint.

You can use a standard voltometer to test the water around your dock. My mechanic did this once when he couldn't figure out why one of his customers pontoon boat was being eaten alive. When he stuck the electrode in the water the needle was pegged to the max. If this isn't your issue at least you can rule it out.

Ron Burgundy wrote:You can use a standard voltometer to test the water around your dock. My mechanic did this once when he couldn't figure out why one of his customers pontoon boat was being eaten alive. When he stuck the electrode in the water the needle was pegged to the max. If this isn't your issue at least you can rule it out.

Like I said, we trailer the boat and it's not kept in a boat slip.