Repairing Crack In Aluminum On Lund Boat

[Dagojoe]

I have an 18' Aluminum Deep V Lund boat with a 115hp Outboard Motor. The transom is clad in Aluminum. There is another piece of alumimum that butts up against the transom on the inside of the boat that looks like it was welded together or had some kid of sealer in the past. It looks like there is a fine crack along this butt joint and it is leaking inside the boat. Any suggestions on how to repair this crack? I don't think you can weld aluminum so I am assuming I would need some type of metal sealer. I am not sure if the wood transom got soaked but hoping it did not.

Thanks in advance for your advice.

Joe

 

[Georgesalmon]

Aluminum can be welded easily but you will probably have to take it apart. clean it up real good and try some 3M 5200, its a sealer and an adhesive.

 

[Watermann]

Some pis of the area you're talking about would be great, one with some perspective and another with the damaged area close up. It sounds like it's the spashwell that has the cracking.

 

[Dagojoe]

Hi guys, thanks for responding. Its raining right now but I will take some pictures and repost as soon as possible. I do have one other question. If I try and lift the motor there is a little bit of flexing on the transom which I am sure causes problems with the joint. Is a little bit of flexing normal? I am wondering if maybe my transom wood is going bad which is causes the flexing and the crack. I am not sure if there is an easy way of checking the wood in the transom without taking it out and putting a lot of holes in my aluminum.

 

[Scott Danforth]

I use my radiator guy to weld aluminum. he welds on busted aluminum boats all the time.

 

[GA_Boater]

Hi guys, thanks for responding. Its raining right now but I will take some pictures and repost as soon as possible. I do have one other question. If I try and lift the motor there is a little bit of flexing on the transom which I am sure causes problems with the joint. Is a little bit of flexing normal? I am wondering if maybe my transom wood is going bad which is causes the flexing and the crack. I am not sure if there is an easy way of checking the wood in the transom without taking it out and putting a lot of holes in my aluminum.

We need some pics for sure, Joe. It sounds like the transom wood may be going south and the aluminum is taking all the stress, hence the cracking. The motor should be rock solid.

 

[Dagojoe]

No Title

Hi Guys. Sorry it took so long to send these. Been raining quite a bit here. I think GA=Boater is right, the transom may be going back but not sure. How hard do you think it will be to replace the transom? Thanks for your help.

Joe

 

[GA_Boater]

Joe - What I see in the pics is the sealant between the transom and splashwell, the whitish stuff, is deteriorated/cracked. That can be caused by the flex you see. Can you look under the splashwell and see if any of the transom wood is exposed and what it looks like. I'm not familiar with how Lunds are put together.

 

[pckeen]

The transom should be absolutely solid - any flex is not normal - it means you should be replacing the wood in the transom.

The aluminum break should be an easy weld for a professional, but hold off doing it until after you replace the wood. If I'm understanding the photos correctly, the crack is between the splashwell bottom and that part of the splashwell that attaches to the transom. My understanding is that the splashwell, in addition to serving as a catch and drain for water, also provides some structural support.

If your transom is flexing, you may get cracking in other areas as well, so my advice is get all this fixed before using the boat further.

 

[WrenchHead]

Appears to me the previous owner saw the cracking and tried to patch with a filler/sealant. But the flexing and expanding will open up the filler/sealant. Probably the wood has decayed allowing the transom to flex and that in turn broke the original weld loose. As suggested you need to replace the wood and then do a fresh weld. You do not want any flexing on the transom.

 

[Dagojoe]

Thanks, sounds like I need to replace it. What looks like white in the picture is actually the weld shining. I don't see any caulking on it. I agree, before I get the weld fixed I need to replace the transom. I guess it should not surprise me with as old as the boat is (1994 model). I already replaced the flooring on it.

GA-Boater, If I look under the spashwell to the transom I cannot see the wood because it is covered with aluminum as well. I am not sure how it is constructed yet. I am not sure if the aluminum on the back of the transom is all one piece (including past the weld). I kind of doubt it because the leak I am getting is underneath the spashwell on the transom (coming out of a rivet). It seems like if that aluminum on the back side of the transom was all one piece it would not be coming out of the rivet. Who knows, it may be cracked someplace else.

Well, my fishing buddy owes me for taking him out all the time. Guess its time to play my card and ask for help. Have no idea what I am getting myself into but hopefully we can figure it out in the spring (unless I can find a warm place to do it in the winter). Thanks everyone for your help.

Joe

 

[GA_Boater]

In a couple of the pics, I can see a cap on top of the transom with screws or boat nails holding it to the wood. I'll guess you can remove that cap, any corner caps and hardware through the wood and remove it. Like I said, guessing without seeing more of the transom.

 

[Watermann]

First order of business would be to remove the motor from the transom and then start in on the removal of the other parts, end caps, splashwell and transom cap.

 

[Dagojoe]

Thanks Cave-Run and GA-Boater. I talked to my nephew and he replaced the transom on his boat. I'm not sure what kind of boat he has but in his case it sounded like a horror story. I told him how I think mine is constructed and he said he will come over and look at it but it sounds like mine will be easier. One nice thing is he has a pneumonic riveter and a winch to lift my motor. He said he would try and help but he lives quite a distance away and a very busy man so I am not going to hold a lot of hope on that. It should be interesting but I am not going to start until early spring(no place warm to do it and I am a cold baby, lol). I will DEFINITETLY be asking a lot of questions as I go through the process. Thanks for your patience.

Joe

 

[bonz_d]

Dagojoe which model Lund is this? On many of the Lunds the wood inside the transom does not extend all the way to the bottom but it is fit between 2 pieces of aluminum. When you can try to post a picture of the transom under the splashwell also of the transom drain. That should provide some clues as to how far down the plywood is going.

 

[Dagojoe]

Hi Bonz_z. I will try and get some more pictures today of the underside of the Splashwell. If I recall correctly, the aluminum goes all the way down to the floor.

 

[Dagojoe]

Sorry, it is a Lund 1800 Fisherman, Adventure series.

 

[Dagojoe]

No Title

Hi Guys. Here are some more pictures I took before closing up the boat. @Bonz-D, I think you are correct, the wood does not go all the way down. In the first picture you can see where it stops above the drain hole.

 

[bonz_d]

Pictures are not very clear as they come up pretty small. But from what I can tell from the 1st picture of the drain the plywood does not extend all the way to the bottom. The tell is that the tube sticks out from the transom. If the plywood went all the way down then that tube would be flush or almost flush. My guess is that the plywood ends at or just below the splashwell.

 

[WrenchHead]

How about taking photos during the repair and post for all of us to see? Good luck on everything turning out to your satisfaction.