Lund front deck failure

The images are rough, but the front of my early 2003ish Lund Fisherman is breaking up… Rivets failing and the decking cracking on both sides. I’m sure it is the stress of the trolling motor and deckhand anchor… but my two cents, what a crap design. The front ten inches is totally loose. Metal is like 1/16″ and no support at all. This is with the wood and everything stripped off, and marked up for my info.

I hope to find from someone to rebuild it with heavier aluminum. I have a fabrication place in town but they are months out and it is a “new” task for them. Anyone ever deal with this that may have some “helpful” advice?

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I’d definitely add a thicker support plate to the bottom side of the new piece. 1/4″ thick or more. Should spread the stresses out more.

Check with the local HVAC installers. Many have on-site sheet metal breaks and may be able to bend a new one up for you. Assuming their breaks are big enough for that size metal.

Common issues on most aluminum boats when used long enough, shearing at bends.
Caused by 3 issues.
1. Low quality aluminum alloy.
2. The radius of a 90 degree bend needs to be at least equal or greater than the thickness of the metal. Basically the outside of the bend it stretching and the bend is now thinner than the thickness.
3. Under built.

Just make sure that the new piece made made entails these elementary principals.

With how that piece looks to be constructed I would suspect that making a crown or cover piece may be the best option. It appears from the pics that the broken gusset actually rolls back and down into the bow gunnels of your boat.
I would think that you could make a crown and the rivet it on top of the existing broken piece. Anyone with a heavier sheetmetal brake could easily handle this task.

How well do you know your local shop teacher? You could easily make a cardstock pattern.
I assume it will be getting ply and carpet over it so it does not need to be a rolls royce finish.

The entire top of the boat is one long piece. I talked to a local large truck/trailer repair (good welders and fabrication) shop suggesting maybe to cut the front half of the broken deck area off and welding. He said no, bend it and re-attach, weld edges only. This is like 1/16″. He indicated using 3/16″ aluminum…. same type of rivets. Problem is they may never get to it – way busy.

That is the only contact I have. A Chicago boat repair place at $175 an hour said $4-5K… My hope was to spend like 1/4 that at most. I don’t have $4-5 grand for this… and that seems insane.

I want to make sure I am going the right path before begging the truck place to fit it in. I’ve never seen this, but figure it can’t be a first time. Wood cover will go right back on. I was thinking new material could come back as far as possible to lap over or under the old.

Would it be possible to cut a piece of thick marine plywood to shape that would extend to top edge of the gunnel and carpet it? Then used stainless steel bolts or screws to secure it to the top of the gunnel? For added strength fit another piece from the back end down to the top of the casting platform. I am not an engineer by any means but that is what i would try.

Is there any channel support under that top piece? I’m sure that it doesn’t help that it looks like Swiss cheese. I bet that there is a lot of flex if there is no support bridging under the top plate.

Look at mobile welders. When I did my trailer steps I had a guy that I found on FB come out and do it for $50.

As Mark mentioned all the breaks happened at the bends, I assume after rivets failed? No cross supports at all. Doing something better than the big rivets has me stumped.

I had hoped for a cross support – maybe a square tube or angle. That could be tied to a vertical support maybe. All good ideas to try to share once I find someone to help.

I did find a metal supply place that bends and cuts metal in town. I am wide open to more suggestions- thank you all.

Hard for me to see exactly how it attaches, assuming rivets?

Could you just replace the aluminum piece with a chunk of 3/4″ starboard and use screws or bolts instead of rivets?

There’s like a hard formed molding that holds the top to the sides. The top has like a second 90 degree bend with a maybe 3/4” flat that is simply riveted to the molding. The entire top is tapered towards the front.

I’m just really disappointed it failed. You guys are giving me hope it can be fixed. Are bolts or welds stronger than rivets?

Chuck Melcher wrote:

Are bolts or welds stronger than rivets?

Pure assumption on my part but steel bolts vs. aluminum rivets? SS bolts would be stronger. And definitely try to add some support underneath.

Can this be too rigid? Is there any reason to think there is suppose to be a certain amount of flex in the front of a boat like this?

Not assuming I could have it made too rigid, just thinking back to the problem in the first place – and the lack of support built into the boat. I’m not impressed with it.

Thanks again…..

Not sure if I am looking at this right, but If what I am seeing is I would take some aluminum U channel cut to fit the out side edge, then cut a top piece to fit and either bolt, screw or rivet it together.