Thread: My jon boat crack

So sorry Tapout, a good old johnboat is a wonderful thing.
Drilling a 3/16 hole at each end of the crack to keep it from spreading is good advice. Filling with Marine Tex is good, as well.
Welding is best. If it were mine, I would drill, fill, and then fabricate a plate to fit over the area out of .072 Aluminum and then weld around or bond it in place. Then you are going to have to relocate the roller and provide some additional support elsewhere. Do you really need the roller? If your bunks are large enough they should do the job. My old Fisher, rest it's soul, had rollers on the trailer but they were positioned in such a way that they functioned as the keel ran up on the trailer. Once up on the bunks, the only support was two large bunks. Rollers and aluminum boats don't really go together. The good news is now you have an excuse to sell it for scrap and get a new one!

Originally Posted by Don French

Do you really need the roller?

That's a good question. It came with the trailer so I just left it on. Perhaps I will see how it goes without it.

Way to much stress on that rib, something is not set up right, get trailer fixed FIRST.

When your boat is up on trailer it should not have weight on a rib, weight should be spread out on the flats between ribs. That rib looks way to worn, looks like repeated hitting something. I would reset trailer to have boat come up on 2 rollers one on each side and nothing in the middle. Just my take.

Originally Posted by Flatwater

Way to much stress on that rib, something is not set up right, get trailer fixed FIRST.

When your boat is up on trailer it should not have weight on a rib, weight should be spread out on the flats between ribs. That rib looks way to worn, looks like repeated hitting something. I would reset trailer to have boat come up on 2 rollers one on each side and nothing in the middle. Just my take.

The wear is from beaching it on rocky shore lines. You don't think that my boat being 16 years old is a factor? I had already moved the boat back on the trailer a long time ago as my tongue weight was too heavy and my trailer tires were bouncing and getting chewed up.

The same thing happened to an old boat of mine. I eliminated the roller and ran carpeted bunks to spread the support over the length of the boat. I put a fiberglass patch over the hole. It was still dry when I sold the boat 2 years later.

That crack is in a bad place, stress and stain from the roller will make it grow. Welding is the way to go. But if thats a thin boat you will need a welder that knows what he is doing. Expensive but good. Some of those gouges don't look good either. I cracked one once across the tailgate and it always leaked, was glad to see that boat go. If you are going to use epoxy, sand the whole area you want to cover, JB Weld or the MarineTex are both good choices.

You will want to have it Tig welded Tap.

A lot of great ideas, thanks to all. I am going to go the cheapest and quickest fix for now. (we all know how that typically ends up) Since I also have my Lund to fish out of if this does not work it's not such a big deal. My outside patch stopped about 98% of the leak so today I removed my front seat and cut open my floor expecting to see wood under it but finding foam.



After removing the foam you could plainly see the crack.



I have applied JB's water weld on the inside as well so we will see how this goes. If this does not hold up I will surely be exploring one of the many options that I was given so thanks again.