My 2011 Lund Impact 1775 previously had paint bubbling all over the transom, especially by the scuppers. It was repainted under warranty back in 2014.

Ive noticed over the past few years that some rivets have a different texture on them, and the splashrails have started to bubble.

At this point, i wished they repainted the whole boat prior, as chances are the paint was crap all over.

This year, I noticed white powdery spots on the edges of the splashrail and hull in a few spots (but the transom area that was repainted is still ok) That's when i figured this probably wasnt a paint issue. Corrosion for sure. And i now have two leaking rivets by the keel on the bow that just started (had water in my hull after my first trip this year, nothing significant though). I confirmed this by filling up the hull at home, a slow drip.

So i decided to take a multimeter and test for continuity. I removed the outboard cables, and everything else. And if i check the negative of Lunds wiring harness and the hull. It shows continuity. And to my understanding it shouldn't, just the outboard motor should. Its too bad as the paint coming off the transom was possibly because of electrolysis. And i most likely have had this problem for a long time. Its too bad that they dont do an investigation of why this occurred, but just repaint it and send it back to you.

Sent photos to Lund and havent heard back in a month. Ill probably be out of luck.

I am more so worried about the integrity of the hull at this point if this is in fact electrolysis. Thinking of pulling the center floor board to see if i can see anything and find where a ground wire is touching the hull. But i think i have to remove the back deck, and center rod locker as they seem to be sitting on top of it. Maybe i can get a whole new wiring harness from Lund.

Just making sure i did the test correctly before i pull everything apart and looking for any insight. I read about crevice corrosion on aluminum boats, but i dont believe thats the problem. Right now batteries are all unhooked as i wait for Lunds response as id rather the problem not worsen, and dont want it to wreck the new stainless x7 prop i just put on either.

I only get out a dozen or so times a year, and the boat never stays in the water (im assuming this accelerates the issue as the anodes break down). But at the moment they all three still look brand new, i do clean them off also.

I added a photo of the leaking rivets, interior of the hull, splashrail. I always thought the inside was that colour because of moisture and what not, but its probably corroding too.

Thanks!

Always something with boats, last year my Xi5 died, parts were backordered for months. Bought an Ultrex after waiting a month and a half and it broke within a month and then I had to wait for warranty repairs on that. Got out on the water a measly three times last year and twice this year so far.

Danbob,
Every motor that I have checked with a meter grounds the -12 volts to the body and crankcase and starter housing.

On every one of these same motors, those same points are connected to the motor mount itself which is connected by bolts to the hull of the boat.

So, I would absolutely expect that every part of the motor chassis has a direct connection to the metal of the aluminum hull on an aluminum boat.

Having said that, every motor that I have ever seen, also has a sacrificial anode on it that is supposed to take care of the electrolysis issue.


I am guessing that your paint issue is most likely caused by poor metal preparation. But, I have not seen it and this is only a guess as a result of not seeing the problem.

Best wishes.

[url]https://www.ifish.net/board/showthread.php?t=65861[/url]

[url]https://www.proboat.com/2014/12/keeping-paint-on-aluminum/[/url]

[url]https://www.cruisingworld.com/how/how-touch-painted-aluminum/[/url]

Rew is correct by stating that the hull is grounded, you didn't read anything abnormal in your meter.

That being said every return should be on a black wire connected to the neg battery post. The hull should never be used as a return path. What this looks like to me is that you have a bad ground somewhere, happens alot on fuel tanks but could be anywhere, and your hull is being used as a return instead of the wire. Your boat is disintegrating, I would check each and every wire connection.

What you have is crevice corrosion, not galvanic corrosion (sometimes mislabeled “electrolysis”). Crevice corrosion is caused when water at the molecular level migrates between a paint layer and aluminum, creating acid in the absence of oxygen. It is most likely to occur at a painted edge such as a rivet, hole, snap, etc. it is cosmetically troubling but otherwise insignificant. It is most likely to occur in saltwater or polluted water, but can be caused even by rainwater. Over time most painted aluminum boats will have it to a degree.

[QUOTE=ltrain;6338174]Rew is correct by stating that the hull is grounded, you didn't read anything abnormal in your meter.

That being said every return should be on a black wire connected to the neg battery post. The hull should never be used as a return path. What this looks like to me is that you have a bad ground somewhere, happens alot on fuel tanks but could be anywhere, and your hull is being used as a return instead of the wire. Your boat is disintegrating, I would check each and every wire connection.[/QUOTE]


Correct ... And just to make it easier to understand as you troubleshoot the issue, and not get confused, it helps to think of it in terms of 2 concepts.

Ground-ED conductors and Ground-ING conductors. ....

... The hull, and the motor mounting brackets on the outboard are tied together to each other ,and the negative side of the battery. This is why they all show continuity with each other. They are "GROUNDED."

In contrast, The negative wiring leads to the battery from each individual circuit or device, lights, pumps ,ignition, sonars etc etc , are "GROUNDING" conductors. They carry current , and complete each circuit. Their circuit path to the battery negative side should never involve the hull. When a boat is wired correctly, though the hull is GROUNDED, it carries no current. Only the wires carry the current.

Unlike a car or truck which uses its chassis as a common ground, for groundING,, a boat should never use the hull as a common ground. It may use a grounding bus to tie some negative leads together to simplify the wiring, but the bus must be isolated from the hull. Unfortunately , especially when adding aftermarket accessories, wiring mistakes can be made. Or as mentioned, a circuit with a damaged or chaffed grounding conductor MAY result in current to seek its path through the hull.

All that being said, as mentioned by another, the cause of your symptom may not even be electrical in nature. But if you end up having to check out all your wiring in a process of elimination as to the cause, Keeping these concepts in mind may help as you probe for problems. Good luck.

Seems about one in a million chance Lund improperly wired the boat at the factory.

I am not familiar with an Impact but I will venture to say there is a standard fuse block in the console. Feeding the fuse block and most everything but the bilge pump is a red and black wire connected to a battery. That black wire is the negative return to the battery avoiding the hull as negative return. Verify you have a fuse panel with proper positive and negative connections to the battery and, if so, end of discussion.

No offense, but your bilge is filthy. Aluminum oxide is white. That brown scuz extends high on the corrugated livewell hoses, so you experienced high water in the bilge and the water was filthy. Maybe that was why the bilge pump or switch didn’t work. Check your switch and pump. You were in really dirty water or you have been washing your decks into your bilge and creating a nice little cesspool under the deck. I suggest cleaning your bilge for the sake of preserving the operation of your bilge pump and switch.

Boat is used in freshwater (Ontario), about dozen times a year. Unplug after pulling the boat out every time, so i have no idea why the bilge looks like that. No water ever comes out, minus a few drops this year because of a small leak from two rivets.

I have never washed my deck once, rarely am out in rain. Bilge pump works fine. If I disconnect both bilge and aerator pumps, continuity still exists between lunds negative and the hull with everything disconnected off the battery. I am assuming livewell hoses look like that because of moisture when its on land stored which is 99.9% of its life...

[QUOTE]
Seems about one in a million chance Lund improperly wired the boat at the factory. [/QUOTE]

I may be wrong but I believe the marina is responsible for some of the final rigging. I have heard of instances where brand new boats were brought home only to find screws through fuels hoses, wires not terminated properly, etc. Also being an 8 year old boat, connections become loose or corroded. Not saying that is definitely the problem but it can very well be.
The paint blisters don't bother me as much as the white powder , that's what had me thinking galvanic corrosion, I hope not for the OPs sake.

[QUOTE=ltrain;6338234]I may be wrong but I believe the marina is responsible for some of the final rigging. I have heard of instances where brand new boats were brought home only to find screws through fuels hoses, wires not terminated properly, etc. Also being an 8 year old boat, connections become loose or corroded. Not saying that is definitely the problem but it can very well be.
The paint blisters don't bother me as much as the white powder , that's what had me thinking galvanic corrosion, I hope not for the OPs sake.[/QUOTE]

You are not wrong on the dealer part.. There is still a vast difference in Dealer abilities.
*Also, when it comes to wiring issues in many cases the owner or one of his buddies applying "farmer rigging" has created some freak issues.

I have been out fishing only to be approached on the water by a guy who bought one of my demos (7 years old now)...from the guy who bought it from the guy who bought it from me...This 3rd owner starts giving me the business about some electrical short in the boat. ...and what am I gonna do about it?

My response was ..."It was working perfectly when I sold it 7 years ago...but it did have different electronics, then."

... good post Itrain.