# Repairing Crack In Aluminum On Lund Boat



## Dagojoe (Jul 16, 2013)

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 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.

Thanks in advance for your advice.

Joe


----------



## Jose' (Aug 31, 2013)

It can be welded. I'd see if ya got someone local and reputable and ask them what they think.


----------



## Dagojoe (Jul 16, 2013)

Thanks Jose. I didn't know that. I will try and find someone that can do it.


----------



## Shortdrift (Apr 5, 2004)

Just for your info, there is wood sandwiched betwee the aluminum on the transom. If the crack is adjacent to the butt joint or on an old repair weld at that joint there is a chance that the wood may be soaked with water. That is not good.


----------



## bountyhunter (Apr 28, 2004)

yep you can weld aluminum, not a easy thing to do, find a really great machine shop to do the work. NO BACK YARD MECH for this.


----------



## bountyhunter (Apr 28, 2004)

just a though, call VIC,s marine and ask for a reference. they should know a shop. mines a 1993 lund pro V 1775 115merc. I,m gonna go look it over tomorrow.


----------



## MassillonBuckeye (May 3, 2010)

Dagojoe said:


> 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 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.
> 
> Thanks in advance for your advice.
> 
> Joe


Lund hulls carry a lifetime limited transferable warranty. I'd recommend calling them and see what they have to say.

http://www.lundboats.com/warranty


----------



## BigDaddy300 (Nov 1, 2004)

MassillonBuckeye said:


> Lund hulls carry a lifetime limited transferable warranty. I'd recommend calling them and see what they have to say.
> 
> http://www.lundboats.com/warranty


Not the older ones.


----------



## Dagojoe (Jul 16, 2013)

Thanks everyone for the feedback. I definitely will make sure whoever repairs it knows what they are doing. @bigdaddy - Yes, I am afraid that the wood may have gotton soaked. More than likely I won't be getting the weld done before the spring and I am "hoping" that it will dry out before then. Calling Lund to get their thoughts about the wood may be a good idea. It looks like it is a tough job to replace that transom wood but I may end up having to do that. Has anyone ever done that before?


----------



## turkeyt (Apr 13, 2006)

Go to Iboats.com and ask around on the forum site. There is always someone who has gone through transom repairs on there.


----------



## bigragu (Jan 7, 2010)

Know you are after a permanent solution to the problem, however, you might try the stop-leak spray, seen on TV, as a temporary stop.


----------



## I Fish (Sep 24, 2008)

turkeyt said:


> Go to Iboats.com and ask around on the forum site. There is always someone who has gone through transom repairs on there.


X2 on Iboats. Also, can you show us a picture or 2. IMO, if it had sealant on it from the factory, I'd replace the sealant with something like 3M 5200, or the like.


----------



## Dagojoe (Jul 16, 2013)

Thanks Bigragu and Ifish. I am going to replace the transom in early spring. When I have the splashwell off I will go ahead and have it welded. I don't think there was a sealant. I am assuming that 3M 5200 would be good for any places that require caulking when I tear everything apart.


----------



## MassillonBuckeye (May 3, 2010)

bigragu said:


> Know you are after a permanent solution to the problem, however, you might try the stop-leak spray, seen on TV, as a temporary stop.


I wouldn't spray that stuff on anything you'd want to then remove it from later.. Nasty stuff.

I just did the transom in my 16.5 Starcraft. Wasn't a huge deal. The peace of mind it provides is priceless! Iboats.coms starcraft forum was invaluable. Even though yours is a Lund, it'd be a great place to start.


----------



## MassillonBuckeye (May 3, 2010)

Dagojoe said:


> Thanks Bigragu and Ifish. I am going to replace the transom in early spring. When I have the splashwell off I will go ahead and have it welded. I don't think there was a sealant. I am assuming that 3M 5200 would be good for any places that require caulking when I tear everything apart.


Yes. 5200 is considered Permanent and for above and below the waterline applications. 4200 is a little more pliable and not considered as permanent. And Home Depot has tubes of 5200 for half as much as anywhere else. Get a quart of Acetone while you are at it because if you are anything like me, you'll get it everywhere. Its pretty messy stuff.


----------



## I Fish (Sep 24, 2008)

Dagojoe said:


> I am going to replace the transom in early spring


If you're going to do that, so far, I can't say enough about Coosa Bluewater 26. Then, if it ever leaks again, just fix the leak. Most all arguments against it are cost related, but, when you weigh in time and labor, it was the best extra couple hundred $ I spent when I did mine. The piece of mind that it brings is worth even more.


Also, I don't know if 5200 is considered permanent on aluminum. 3M only mentions wood and fiberglass. I consider it more like a high quality gasket.
http://solutions.3m.com/wps/portal/...sive-Sealant-5200?N=5510818+3294314622&rt=rud


----------



## MassillonBuckeye (May 3, 2010)

I Fish said:


> If you're going to do that, so far, I can't say enough about Coosa Bluewater 26. Then, if it ever leaks again, just fix the leak. Most all arguments against it are cost related, but, when you weigh in time and labor, it was the best extra couple hundred $ I spent when I did mine. The piece of mind that it brings is worth even more.
> 
> 
> Also, I don't know if 5200 is considered permanent on aluminum. 3M only mentions wood and fiberglass. I consider it more like a high quality gasket.
> http://solutions.3m.com/wps/portal/...sive-Sealant-5200?N=5510818+3294314622&rt=rud



3M gives *Metal the highest bonding rating(H**) saying primer recommended and 1/4" depth.
http://multimedia.3m.com/mws/media/323623O/adhesive-sealant-brochure.pdf

If you don't believe that then you've never tried to remove it. I've seen guys blow torching the stuff, wrecking their fiberglass with it etc. This is far more than a gasket material.

http://multimedia.3m.com/mws/media/323623O/adhesive-sealant-brochure.pdf


> Extremely strong
> Non Shrinking
> Permanent bond





> APPLICATIONS QUESTIONS
> &#8226; Am I making a structural, general, bedding or sealing bond?
> &#8226; Will I ever have to disassemble?
> &#8226; Have I cleaned and/or scuffed the surfaces to be bonded/sealed?
> ...


----------



## I Fish (Sep 24, 2008)

MassillonBuckeye said:


> 3M gives *Metal the highest bonding rating(H**) saying primer recommended and 1/4" depth.


I've removed it from both. I don't know if it had been primed, but, in my experience, it comes off of aluminum considerably easier than it does fiberglass. On aluminum, 3M only gives it a 200lb psi rating, whereas it gives 400psi on polycarbonate, and an average of 475psi on wood. I consider it a gasket because I always use it in conjunction with screws, rivets, etc.

http://multimedia.3m.com/mws/media/158830O/adh-seal-fast-cure-5200-tech.pdf


----------



## MassillonBuckeye (May 3, 2010)

I Fish said:


> I've removed it from both. I don't know if it had been primed, but, in my experience, it comes off of aluminum considerably easier than it does fiberglass. On aluminum, 3M only gives it a 200lb psi rating, whereas it gives 400psi on polycarbonate, and an average of 475psi on wood. I consider it a gasket because I always use it in conjunction with screws, rivets, etc.
> 
> http://multimedia.3m.com/mws/media/158830O/adh-seal-fast-cure-5200-tech.pdf


We're just arguing semantics at this point! I'll put it this way, that stuff is just about as permanent as you can get for an elastic adhesive. 

This is what I'm talking about. From your link:


> Applications:
> 3MTM Adhesive Sealant 5200 Fast Cure is for permanent assembly of wood and fiberglass parts bonded
> together. If a non-permanent bond is desired, use 3MTM Marine Adhesive Sealant 4200.


Metal to metal you'd obviously want to weld. I think we've given him enough information for him to base his decisions on 3M 5200 anyhow


----------



## Dagojoe (Jul 16, 2013)

Well started working on the transom a few weeks ago. What a job this has been so far. I am lucky and grateful that my motor never came off and the boat did not sink!!!! The transom wood was like mulch. Most of it came out with a vacuum cleaner and some hacking with a crow bar. I kind of lucked out because I was able to get to all bolts except one of the tow hooks on the port side. Had to cut a 4" hole in the side to get to it. I'll just cover it with a plate. I did not have to take the splash pan off whch was great because there are a ton of rivets on it. 

Making the new boards out of 1" Cement Form Board(NOT Cement Board) and 1/2" Marine Plywood. Used 1/4 Luan to shape a new board. Got the boards cut and sealed them with CEPS. In the process of painting them to give them a nice water barrier (Keep in mind that I am 65 and looking to get only 10 more years out of the boat). Will be putting some 3m5200 around the edges of the boards then screw the boards together (and fill the screw holes with 5200). Hopefully I can start putting the boards in tomorrow. Have about 50+ hours into this so far. Cost is about $500. (also replaced my gas and oil lines and primers bulbs). Would have cost more but I got the 1" Cement Form Board from my nephew, he used it on his boat and had left over boards). Let the fun continue. PS - had the crack in the splash pan welded for $30.


----------



## brent k (Nov 10, 2013)

I just did my 16ft starcraft transom 2years ago. Yes to know the strength it gives back to the boat is serious peace of mind. I did mine in about 25 hours probably to include drieing time of coats of sealers i used on the wood. Then following year i gutted interior and rebuilt it from scratch hmmm 500 +-hours lol. The biggest thing i can suggest is pretty much what you have already posted seal. Seal everything then if you think its gonna get moisture seal it again. Oh wait and yes seal it again. And another thing i did is on my splash pan i put a bead of 3m sikaflex directly across where the pan seams to the transom. 3m sikaflex is whT i used as my sealer. Stuff is flexable but pretty much has to be torched off of metal or wood. Used it at work on shipping containers lol good stuff. Good luck on the repair and keep us posted on how its going.


----------



## crappiedude (Mar 12, 2006)

Nice follow up post. A lot of time you hear about the problem but you don't hear about the repair. Thanks for posting.


----------



## sherman51 (Apr 12, 2011)

most cracks on aluminum need to be stopped drilled before being welded. you go to the very end of the crack on both ends and use a small drill bit and drill a small hole in the end of the crack. this stops the crack from continuing to crack after its welded.
sherman


----------



## Dagojoe (Jul 16, 2013)

Thanks Everyone for your replies. I definitely went overboard on sealing the boards and anyplace water could possibly get in. Should be putting the motor back on any day. While I am doing this and have access to a pneumonic rivet gun I think I am going to partially fill my boat (up to or close to the bottom of the flooring) and check to see if I have any rivet leaks. My nephew did this and found about 8 rivets leaking. I don't think I have this but can't hurt to check.


----------

