Fixing corrosion holes in my 1997 Monark Pro 1700

[san dimas]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

I'm going to make sure there is nothing grounded to the boat. These anodes, are they on the motor or the hull?

 

[san dimas]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

I'll also look around for any stray metal, like pennys. Thanks for the suggestion. If someone left this boat on the trailer with lets say a radio or something on would this cause the problem. I also noticed that when the main power switch is off the trolling motor will still run.

 

[jbcurt00]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

This thread begins w/ a bit of corrosion too, but has been quite the journey:
My First StarCraft; 1975 18' SuperSport

 

[Grandad]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

That corrosion looks to be pretty extensive and may have structurally weakened your boat. The only reasons that I can see for it to be confined only to one area are as mentioned: battery acid, dissimilar metals nearby (eg copper) or also by water trapped in a space that was created when a previous repair was made. The fact that there's a row of rivets at that point makes me think that someone may have taken a short cut when they applied a patch inside the hull by bridging the tails of the rivets creating a space for water to get trapped. Trapped water will become acidic and eat the aluminum. Any patching should include a bedding material (eg 3M5200) between patches to totally exclude water. I think I'd be tearing up some flooring to get a better look. - Grandad

 

[Grandad]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

I'm going to make sure there is nothing grounded to the boat.

Best of luck with that. Your problem will be to try to keep your grounded metal engine from touching your metal hull. You can try, but you're not likely to succeed. As long as you don't use the hull as the negative ground path for supplying your electrical components, you won't have a problem with the hull being grounded. The corrosion you have isn't likely caused by electrical circuitry. - Grandad

 

[san dimas]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

Well I patched all the holes with PC-11 and plan on putting it in ther water on Thursday. I'll let you know what happens. At what point do I give up and scrap the boat Or am I just over reacting. I would still like to get to the other side of this corrosion and see what is going on, but if this stops the leaks then I'll enjoy it for a while before fixing it.

 

[jbcurt00]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

Depends on what caused the corrosion & whether it started from the exterior or from the interior. Based on what can be seen THRU the corrosion hole, and that this is a seam between 2 pieces of the hull:

It looks like there is more damage between the 2 pieces and you're only seeing the exterior damage. I would think the 2 pieces of hull should be touching, and not separated as they appear thru that hole.

If you've repaired the holes, and it doesn't appear to leak when you drop it in the water, just keep an eye on the repair and all the area around it.

When you get time, read thru BlueFin's project I linked earlier. It has been a journey w/ lots of additional damage that wouldn't have been found w/ out a complete tear down & exceptionally through inspection of every rivet, seam & hull surface.

I hope you've got it fixed & you don't have any further problems.

 

[gm280]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

First of all, I seriously don't think your boat is anywhere near the "Scraping stage" myself. A little quality attention now to fix the obvious issue now will yield years of boating from you boat. I would be very interested in exactly what is under that area and do some investigation into it. You just never know what you will find until you do some exploratory surgery and look. And once you do discover the cause and repair it, your confidence level in your boat and pride level will go through the roof...

 

[Fleetwin]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

First of all, I seriously don't think your boat is anywhere near the "Scraping stage" myself. A little quality attention now to fix the obvious issue now will yield years of boating from you boat. I would be very interested in exactly what is under that area and do some investigation into it. You just never know what you will find until you do some exploratory surgery and look. And once you do discover the cause and repair it, your confidence level in your boat and pride level will go through the roof...

I agree. Enjoy it. "Tinnies" are pretty tough and not too hard to fix.

When you get time, have a look on the inside.

BTW, I disagree with Grandad's statement above. The engine is grounded to the battery via the negative battery cable.

I would make sure BOTH ENDS of that cable are clean and tight. BOTH ENDS.

Enjoy!

 

[saginawbayboater]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

View attachment 220240View attachment 220241View attachment 220242View attachment 220243

Those pictures are of bondo. That stuff isn't even water proof! That ticks me off someone would sell that boat that way!!!!

 

[Grandad]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

BTW, I disagree with Grandad's statement above. The engine is grounded to the battery via the negative battery cable.

?? That was my point. Sorry if I didn't explain it very well. - Grandad

 

[san dimas]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

I'll try and post a picture of the boat, that way you will know why I like it. It should give me exactly what I'm looking for in a fresh water fishing boat. Fortunately, I didn't pay too much for it. Most of the lakes I fish have 10 mph speed limits so I won't be stressing the hull too much.

 

[san dimas]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

 

[san dimas]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

The Force has issues so I'm going to part it out and repower with a Mercury 60 hp Bigfoot.

 

[Watermann]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

San, your boat is very fixable but not from the outside. I can tell one thing for sure that corrosion was caused from the inside out and tying to stuff any kind of goop in a hole from the outside is not a repair IMO. There is no handy man in a can that will from the outside, seal a leaky tin boat with corrosion holes or cracks or loose rivets.

First off the cause of the corrosion is still inside there and now just has goop stuffed inside with it along with trapped moisture. If it were me, I would tear into that sucker with the determination to save my boat. Rip out everything between you and the corrosion, clean it up spotless, dry it out, repair from the inside using marine tex or POR, 5200, splint patches of aluminum riveted in as well to cover the repairs.

Best of luck to you on the repairs.

 

[classiccat]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

I see some schmeg oozing out of the top of the seam. It's possible that someone sealed it using a product that contains copper.

Was the boat restored at some point?

If that's the case, you have to remove the deck (I'd do that regardless), open-up that seam and clean that junk out.

 

[Woodonglass]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

Even though I'm NOT a "Tinner", I might be in the future and I find this subject of Corrosion a bit intriguing so I've been "Googling" and researching and found some things that might be of interest to some of you. And then again...Maybe not. But here they are anyway, cuz I can't stop myself...

Electrolysis | Mastervolt

Types of Marine Corrosion - BoatTECH - BoatUS

Nautech Marine - Taking Care of your Aluminium Boat

http://www.boultonpowerboats.com/PDFbrochures/Zinc-1.pdf

http://newboatbuilders.com/docs/CorrosionOnBoats.pdf

Aluminum Boats and Corrosion

 

[jbcurt00]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

Nice reading. Thanks

 

[san dimas]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

Thanks woodonglass, that was very informative. When I removed the center inspection panel I found an old single edge razor blade all rusted up. I also found a washer back in the bilge. The next thing is that the seat pedastals were mounted with a few carbon steel sheet metal screws. I never knew these boats were so sensitive to different metals. I don't know the history on this boat but I bet it was used in salt water. It is posible that it had some poor repairs done to it in the past. I'm going to take to the lake in a couple of hours and see if it leaks. If it doesn't I'll use it for a while but I'll eventually have to tear into it.

 

[san dimas]

Re: Fixing corrosion holes in my 1997 Monark Pro 1700

I floated the boat today and didn't have any leaks:joyous: I realize this only a temporary fix but at least I can use it for a little while.