Small crack in hull~need your help guys!!!

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YamahaC40Guy

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Well, never thought I'd have to ask this question, but here I am...hat in hand. :shock: First off, the back story. When I first ran this boat almost 2 years ago, I noticed a slight buckling sound from the bow when I hit waves a little hard. Sounded as though the aluminum was being pushed in, and popping back into shape immediately. I didn't worry, assuming that tin boats are built to flex. Fast forward to this spring, I thought I'd address the very slow leaks the boat had, and did. One was along a seam on the port side, one ahead of the port-side/bottom strake. Water test was a success! With some use (and after hitting the odd big wave, I noticed a slow leak again and upon investigation, noticed that the MarineTex epoxy had chipped off immediately in front of the strake. Slow leak was back, but worse was the realization that this buckling might be putting undue stress on the aluminum just ahead of the strake or at the very least, it was bending here. Here is a crappy illustration of the points I'm talking about;

CRACKEDhull.jpg


So, 3 days ago, I was running at about 1/2 speed and hit the wake of another boat fairly hard and heard a sharp crack/pop sound. (along with that buckling sound) I thought it might be a rivet popping, but I was wrong. The slow leak turned into a "not so slow" leak and when I pulled it out of the water, noticed a 3/4" long crack just ahead of the starboard strake. I think this confirms that it is the flex in the hull causing these problems, but I don't want to repair the leak unless I can remedy the flex? What should I do????? Two ideas come to mind, neither of which I think I'm set-up to do. (nor am I sure they will solve it)

1. remove the deck, and have a rib/structure pc. made that runs inside from the mid bench up towards the point of the bow. This would need to be riveted or welded.

2. have boat/floatation foam shot into the cavity under the deck in the hopes that the outward force of the foam would keep things rigid. I don't use this space really, but would give it up to remedy this bigger issue.

BOAT2-1.jpg


Hope you guys have some insight...I'm lost!

Thanks,
Rob
 
Just remember what ever you do don't weld too close to any seams as they may start to leak from the welding heat.I would come up with a brace & rivet it in.
 
I do not believe either of your proposed solutions will solve your problem - you need to fix a brace point that is no longer holding - something has come loose to cause your problem.

You can also just put an aluminum plate over the area (inside the boat) and weld / rivet that to add strength, fix the leak 1st of course
 
Hey guys~thanks for the responses so far, keep them coming! Captain Ahab~as a DIY guy, I am SO reluctant to call in a pro until I've tried a few ideas myself, but called a local/reputable boat repair place this morning. (they do warranty repair on aluminum hulls) Anyhow, the chap I spoke with suggested the same thing over the phone that you've mentioned. He asked the motor size, then said that wouldn't have been the issue, rather that something structural has probably come loose. Fingers are crossed! I may take it up there first thing in the morning, but ****...this is my favorite season to be on the water. Can't be w/o my baby!!!!
 
He asked what size motor you are running because overpowering is what usually causes the buckling, or "oilcanning". Too big a motor puts too much stress on the bottom of the hull at speed and when in chop. It could also be too much weight up front, but looking at the pictures I don't think that is the culprit either. It could be age or abuse in the past (overpowered for instance) do you know the history or are you the first owner?

Check the structure and make sure nothing has come loose, if nothing is found build a brace and rivet it in, that's what I would do. I would also go ahead and add some foam, can't hurt anyway and will minimize further flex if there is any. Regular two part foam isn't structural, but there is one that is, I just can't remember the name right now.
 
I bought a 14' Alumacraft boat that had been damaged while in storage. Something fell across the bottom of it. As a result, there were two tears about 3-4" long on each side. I found a guy who builds race cars and knows how to weld aluminum like a real pro. He welded the cracks and they do not leak a drop. He used a "puddling" technique so as not to distort the metal around the cracks too much. Don't think that you are not going to see where the crack is, but a good welder can fix it and make it look decent.
 
Hey "Rat"~I'm the 3rd owner, but probably the 100th+ user. The boat belonged to a marina originally, used as a renter. All I know is that it was a tiller at the time, and probably not a 40hp either. The owner previous to me added a console, and ran a 40hp Johnson for a couple of years. I added everything else. There is no appreciable weight up front, other than the trolling motor and anchor~the deck is very light. BUT, the overall boat weight was increased a fair bit by the addition of 2 batteries in the rear to power the 24V trolling motor. So, if O/A weight is a factor here then yes, I could imagine that might be the issue. Around 8 gallons of fuel on board, 3 marine batteries (2 deep cell, 1 cranking) Minn Kota 65lb. thrust trolling motor...my beloved Yamaha...?

This buckling or "oilcanning" (never heard that term) seems to be a factor pushing through waves as opposed to the bow dropping down on the water..if that makes any sense. Regardless of what causes this, it needs to be remedied. Unfortunately, I'm not sure a home-grown remedy will cut it. I'm planning on bringing it to that boat repair place I mentioned in an earlier post, and sooner than later. I appreciate all the help/comments, and will report back with what they tell me. Whether I keep this boat forever, or sell it in a year or two, I want to be confident that the hull is sound. I wouldn't want to buy a boat with some hidden issue, so I sure don't want to sell one that way.

Thanks again guys,
Rob
 
Get someone to take a video of your boat on plane.It sounds like to me that the motor is trimmed in to much causing the bow to plow through waves instead of the bow rising over them.Remember, when you're on plane only the rear 18 inches of the hull should be supporting the boat on the water.
 
18"? Really? I've never heard that. I keep the motor trimmed-in (down/prop closest to the transom) for the "hole shot", lifting the boat out of the water then lift it once it hits plane. On calm water, near open throttle, I'd say a little more than half the bottom is in contact with the water. There is a "sweet spot" with the trim of course, you can feel it.

The boat moves quickly, but the "oilcanning" can occur even when it isn't going that fast. It seems to have more to do with the size of wave, and the angle I hit it. Hope that makes sense.

Rob
 
Hey guys, said I'd report back...so here we go. I just got back from a boat repair shop, the owner surveyed the situation and gave me a quote. Ughhh...

So, he pointed-out a host of issues that probably contributed to the damage, and oilcanning that caused the crack. In no particular order;

1. Rivets~spread too far apart (design issue) on structural pcs.
2. Lightweight ribs that stop short of where required
3. No foam in seats

There were a few other things, but by then...I was starting to stress-out about what the repair would cost. The damage to be repaired includes missing and loose rivets, addition of new rivets where there should have been some to begin with, removal/replacement of inner ribs and additional structure added. Oh yeah, and the crack fixed. :( Estimate~$1500 before tax. (Canadian dollars) Seems fair, but allot more money that I was hoping.

So, I'm inclined to give the go-ahead and have this done right....any ideas/comments? An option I'm considering is selling it "as is" and banking the money towards a bigger boat in the next year or so. Not what I want to do though.
 
For $1500, couldnt you buy another hull and move your motor and stuff over then sell the old one off as scrap to get some money back out of it? That just seems like a ton of money for a repair..
 
I get the logic, but $1500 won't get me a boat, on a trailer up here that doesn't need work. There is a ton of money/time put into mine that I'm not sure I'm prepared to do again to possibly save a few bucks. I'd hate to put the $1500+ into an older boat like mine...believe me...but I'm not a boat builder and don't see myself having the time/resources to take on all the rigging required. Also, the number of side console boats that come up for sale w/o motors and on trailers is pretty much nil.

So...it's damned if I do, damned if I don't. Still pondering the options. Anyone want to buy a boat? :shock:
 
You will have to decide with the factors in your particular area but there is no way I would pay $1500 for a repair to that boat around here. I can buy an entire boat for that kind of $.
 
Hey Quackrstackr~you're the second person to say something along those lines, but what exactly can you get for $1500 in your neck of the woods? Jon boats are of no use to me with the size of lakes I fish, and they practically give those away up here for that reason. So, if you're suggesting that I use the $1500 to buy a new boat, it would be a 12' car topper in rougher shape than mine, with an ancient 9.9hp tiller and no trailer. Not sure a boat like that will suit my needs.

$1500 is allot of money for this repair, agreed. Still on the fence, but have told the shop not to start work.
 
Sounds to me like you need to re-seat some rivets, add a little support bracing, weld the crack and add a little foam.

Rivets can be had for $10 for 100 count box
HTS 2000 is $65 a tube (1 pound) for welding the crack
Alu. angle 1/8" can be had for about $35 a stick, even though you may need only about 3 feet
2 Qt of poly foam is $32 (2 cubic feet cured)
You proly have the tools required, MAPP or Propane torch (for HTS 2000), hammer and dolly (I use a 3 pound sledge hammer as a dolly), drill and drill bit, some way to cut the Alu angle.

For $150 (plus shipping) you have the supplies for your repair, slightly more when adjusted for CDN. Proly take 4-6 hours to complete.

I wouldn't condemn the boat. Production boats many times leave a lot to be desired; companies make them as cheap as they can then de-rate them to get away with too wide rivet spacing, inadequate transom width/depth or shorted bracing. This usually doesn't go well with renters who have very little regard for a boat that isn't theirs! Your hull has proly taken some serious abuse, and she is showing it. The one good thing tho is it is a great place to start improvements! You have a boat that fits your design program, got it for a good price, but just needs a little work, love and maintenance!

I say get her fixed, or do it yourself (I know you can!) and then fish her like she was meant for it! :mrgreen:
 
Hey guys~thanks so much for all the input, and details offered via PM. I'll keep you updated as I begin the work next week and if I'm patient enough, photograph the process. I'm losing valuable fishing time with each passing day, so I'm anxious to implement some of the ideas you've all be generous enough to share.

Have a great weekend,
Rob
 

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