Repairing stress cracks in a riveted aluminum boat

[Axhammer]

Need more pictures, a view of where the bend starts and ends (inside & outside). Is it the same on the other side. If not, a picture of the other (good) side, what it should look like, would help.

 

[Axhammer]

a picture

 

[JonM]

a picture

View attachment 121873

Sorry I was fishing on my friend's boat today. I will pull my boat out of the garage tomorrow morning and get you pictures of both sides. The hull has a good side (port side) which isn't bending and the bad side (starboard side) which is bending. I'll try to upload a video too

 

[JonM]

This is the good side but I noticed the hull is also starting to bend down a little bit towards the back of the boat. But this is the “good” side.

 

[JonM]

This is the bad side where the hull is bending down towards the edge. The worst of it is from the rear to middle of the boat and it improves towards the front.

 

[Stand Up]

This is the bad side where the hull is bending down towards the edge. The worst of it is from the rear to middle of the boat and it improves towards the front.

Perhaps that was caused by a ratchet strap that was tightened too much at one time or another. I'm not sure how to straighten this out other than trial and error.
Anyone else have ideas?

 

[JonM]

a picture

View attachment 121873

How do these work? Can I use them if I only have access from the outside? I couldn't find any instructions online but I found them on that website from the part #. There's a floor in my boat so I don't have access from the inside.

 

[LDUBS]

OK, this is really seat of the pants and could be completely off base. Instead of the trailer bunks sitting flush against the hull, the bottom strakes sit on top of the bunks. Could that have put upward pressure on the ribs causing this to happen, especially if loaded unevenly? I'm thinking of the interior picture showing a gap under the outer part of the rib in one of the cracked areas.

 

[LDUBS]

Perhaps that was caused by a ratchet strap that was tightened too much at one time or another. I'm not sure how to straighten this out other than trial and error.
Anyone else have ideas?

Well, since you asked, I’m going to toss this out and see if it floats.

I don’t think I would necessarily try to straighten it all out. I would apply patches but maybe slightly different than what has been discussed. I’m assuming the outer ends of the ribs on the bad side are similar to the one pictured in image 4250.

Here is where I get on thin ice. Remove the two existing rivets where the depressions are. See if a small thin patch could be put on the inside between the rib and the hull skin. That would remove the existing gap that the rivets are trying to close up. Then when the rivets are reinstalled, they won’t be trying to close the gap and dimpling the hull skin because the gap will be gone.

Is this completely crazy?

 

[Keith Kirchoff01]

Thank you for your input, I will try my best to get more pictures today. It's going to be a couple weeks before I can attempt this repair because I'm recovering from a broken leg. But in the meantime I'm buying all the materials I need to successfully make this repair. Also I work at West Marine and I can get almost everything I need from there, I saw someone recommended G-qflex instead of 5200. What are your thoughts on this?

This is the good side but I noticed the hull is also starting to bend down a little bit towards the back of the boat. But this is the “good” side.

A very rough idea of what a lap patch might look like.

View attachment 121774

I am not sure what you mean.is this gust size of another piece of aluminum to rivet on.

 

[Axhammer]

In the picture the wing nut is backed off all the way, allowing full extension of the pin. When the wing nut is tightened the pin expands and draws into the body. It has about 1” of travel to compress the whatever the pin has been inserted into. These are for blind applications.

 

[LDUBS]

I am not sure what you mean.is this gust size of another piece of aluminum to rivet on.

What the heck kind of fish is that?

 

[JonM]

In the picture the wing nut is backed off all the way, allowing full extension of the pin. When the wing nut is tightened the pin expands and draws into the body. It has about 1” of travel to compress the whatever the pin has been inserted into. These are for blind applications.

Thanks I just ordered 3 of them, coming in on Tuesday next week. I'll keep you guys posted when I start the repairs.

 

[Stinnett21]

What the heck kind of fish is that?

Spoonbill cat?

 

[Keith Kirchoff01]

Spoonbill cat

?

I don't no how that Pic got on here.right spoon bill. Was using a purple jid an minnow.

 

[Axhammer]

You need high quality, round & perpendicular holes for theses cleco’s & rivets to work best. If you mess up the removing the old rivet, you will have to go to the next larger size rivet, to get a clean hole.

 

[JonM]

You need high quality, round & perpendicular holes for theses cleco’s & rivets to work best. If you mess up the removing the old rivet, you will have to go to the next larger size rivet, to get a clean hole.

I'm getting those Cleco's by Monday night, a little sooner than expected. I'm bringing my boat to the marina that I repowered my boat with and my mechanic is helping me with the repairs. He's familiar with this repair job. We're going to lift the boat up on the travel lift and put it on stands so we can get under it. I plan on carefully drilling out just the heads of the old rivets and using a pointed chisel to carefully punch out the old rivets. Do you think this is a good idea? Thanks for all your help and recommendations.

 

[Axhammer]

Yes, drill the rivets when removing them. I suggest you start with a bit smaller than the rivet diameter. If you go off center with a smaller bit, you still have metal left to save the hole. If you use a 1/4” bit to drill a 1/4” rivet, and give off center with it…you just blew the hole up.

 

[thill]

I know that I'm butting in, but I don't drill my rivets out much anymore. I use a razor sharp chisel and a nail set. (or small punch)

You take the chisel and lay the beveled side flat against the hull, so it doesn't dig. Then you tap it with a hammer and slice or pop the head off the rivet. After a few, you will learn the perfect angle to pop them off. Then center the nail set on the rivet's tailpiece and give it a sharp blow or two and it will pop right out.

A lot of times, I will work from the inside of the boat. It seems a bit easier that way, and you don't have to worry about scratching the boat.

My brother-in-law was replacing rivets on his leaky jon boat, and I found out and asked if he needed help, and he said no, he didn't. The next day, I stopped by, and he was drilling and drilling and fighting every rivet. I showed him the chisel method, and he blinked and looked at me and said, "You have GOT to be kidding me! I've been fighting this thing for 2 days, and THAT's all I had to do?" We worked together for about an hour and replaced a ton of rivets and bucked all of the old ones, and his boat is 100% leak free to this day. It's a game-changer in my opinion.

Every once in a while, you will find one that just doesn't want to pop out. Shave off the tailpiece AND head, and usually it will pop out then. Very rarely, it won't. Usually, this will be in very thick, laminated areas, like corners or bow caps. In that case, center a 1/8" bit and drill it, then punch out the rest of the tailpiece. You can get most anything out cleanly with a little practice.

The chisel/punch method is really fast and does not damage the holes at all. I keep some 1/4" rivets just in case I mess up a hole, but I don't think I've ever had to upsize a rivet due to my removal. I HAVE had to upsize rivets in badly corroded areas to get to clean metal, though.

Always make sure each rivet is tight and right before moving on to the next one. Once you get comfortable doing solid rivets, removal and installation goes really fast and they never leak.

I wish you the best on your project!

 

[JonM]

I know that I'm butting in, but I don't drill my rivets out much anymore. I use a razor sharp chisel and a nail set. (or small punch)

You take the chisel and lay the beveled side flat against the hull, so it doesn't dig. Then you tap it with a hammer and slice or pop the head off the rivet. After a few, you will learn the perfect angle to pop them off. Then center the nail set on the rivet's tailpiece and give it a sharp blow or two and it will pop right out.

A lot of times, I will work from the inside of the boat. It seems a bit easier that way, and you don't have to worry about scratching the boat.

My brother-in-law was replacing rivets on his leaky jon boat, and I found out and asked if he needed help, and he said no, he didn't. The next day, I stopped by, and he was drilling and drilling and fighting every rivet. I showed him the chisel method, and he blinked and looked at me and said, "You have GOT to be kidding me! I've been fighting this thing for 2 days, and THAT's all I had to do?" We worked together for about an hour and replaced a ton of rivets and bucked all of the old ones, and his boat is 100% leak free to this day. It's a game-changer in my opinion.

Every once in a while, you will find one that just doesn't want to pop out. Shave off the tailpiece AND head, and usually it will pop out then. Very rarely, it won't. Usually, this will be in very thick, laminated areas, like corners or bow caps. In that case, center a 1/8" bit and drill it, then punch out the rest of the tailpiece. You can get most anything out cleanly with a little practice.

The chisel/punch method is really fast and does not damage the holes at all. I keep some 1/4" rivets just in case I mess up a hole, but I don't think I've ever had to upsize a rivet due to my removal. I HAVE had to upsize rivets in badly corroded areas to get to clean metal, though.

Always make sure each rivet is tight and right before moving on to the next one. Once you get comfortable doing solid rivets, removal and installation goes really fast and they never leak.

I wish you the best on your project!

Thanks for your advice, I will try this when I start working on it tomorrow!