small leak repair with expanding urethane foam

[adam0351]

I have heard of some people using marine plywood cut to fit over the floor in an aluminum boat, then pouring in an expanding urethane foam to essentially fill in the leaks. Anyone tried this or know of someone who has? It seems that this should permanently fill in any leaks and add buyancy to the boat with the foam but I am not exactly sure the best way to attatch the plywood to the existing floor. I tried to look it up on here first in the repair sections before I posted this but didn't see much about it. Thanks in advance for any help on this.

 

[5150abf]

Re: small leak repair with expanding urethane foam

Welcome to iboats.

No, you don't want to do that because when it doesn't work you then have foam stuck to the boat and the leak will be almost impossible to repair then.

You want to use a product called Gluvit(sp) it is made to seal leaks and is permenent.

Actually the best fix is to rebuck the rivet, they work lose over time and you need to rebuck them once in a great while.

You want to put a few inches of water in the boat and mark all the rivets that leak, only use 2-3'' of water since it is heavy, then get a freind and put him outside the boat with a steel hammer and you get inside the boat wiht a steel hammer and hit the rivet 2-3 times and it should seal the leak, this is the best and proper repair.

 

[metriccrescentwrench]

Re: small leak repair with expanding urethane foam

In additon to what's been said, marine plywood is NOT waterproof - when used in the deck it always has fiberglass on it. Also, it's a misconception that adding foam will add bouancy to a boat, what's really happening is that you're replacing air with something that's heavier (foam), which is actually reducing buoyancy somewhat. What foam is used for in boats is flotation in case the boat becomes swamped (in that instance the foam is displacing water).

 

[adam0351]

Re: small leak repair with expanding urethane foam

Thanks for the info guys, I am new to boating and this is my first boat but I would rather do things right the first time and avoid headaches later on. I will probably wait till the spring time to tighten the rivets back up since I wont need the boat till then anyways. I would do it now but I don't have a garage to work in and temps are right around the freezing mark where I am.

 

[Silvertip]

Re: small leak repair with expanding urethane foam

If you have no idea what "bucking rivets" means or how to do it, just use those two words in the Google search box. It is explained in detail and is a far better way to repair leaky rivets.

 

[oops!]

Re: small leak repair with expanding urethane foam

yeah....to throw in my 2 cents worth......

you said..........."i have heard of people using ply and foam to fix an aluminum boat"

i will gaurentee you this repair will fail.....and those people will be feeling stupid about trying to put a wooden band aid on a metal boat......
this repair is more of a if i dont see it i wont know its there type.....

alum can be welded if its a real hole.....and if its just rivets.......fix as suggested above

 

[adam0351]

Re: small leak repair with expanding urethane foam

As I already stated above, I am new to this and realize after asking that the best course of action is to rebuck the rivets and that is what I plan to do. I was interested in the idea of the ply and foam tactic only due to the fact that the wood on the transom needs to be replaced and I planned to buy enough for both jobs if I went that rout. Now that I know that using ply and foam to fix the floor is not only a horrible idea, but also stupid and probably going to cost more money down the line to repair when I could have done things the right way the first time I will not do that. Being new at this is why I asked questions first from people who I figured would know more about the topic than I would, hence learning how to do it the right way before screwing anything up diving headfirst into something I knew nothing to very little about. Again, thank you to all who gave such helpful advice, and know that I will put it to good use.

 

[oops!]

Re: small leak repair with expanding urethane foam

if you want to do the transom on the boat.......the restoration section has many examples of how to do that....

post pics of your boat and we can guide you.

 

[Bob_VT]

Re: small leak repair with expanding urethane foam

Welcome to iboats.

I will move this post to the restoration section. I think there are examples of one or two aluminum boat restorations.... (or is that one or two HUNDRED!!! )

 

[jspano]

Re: small leak repair with expanding urethane foam

what size and type alum boat do u have? many people use plywood for flooring and transom restores, high grade exterior is acceptable and if you want to add foam for floation use extruded polystrene(sold in sheets 4x8 pink,yellow or blue depending on manufacture) search out boats similar to yours and read,read and re-read them. this will prepare you for you restore. good luck and have fun... plenty of good, knowledgable people here! why?, because they have done it before!!! read and learn from their hits and misses.

 

[Yacht Dr.]

Re: small leak repair with expanding urethane foam

Listen to 5150abf ..he had it right spot on....

YD.

 

[adam0351]

Re: small leak repair with expanding urethane foam

I would put up some pics but like I said I hadn't planned on doing much work till spring time, just getting some research done for now on what exactly I needed to do when I went about doing it. My boat is a 14' but not sure on the exact make as the guy I bought it from didn't know either and told me he just wrote in lund when he registered it. I did notice the info plate on the transom is still there however it is painted over so I will try to clean that up when I am ready to work on it so I can look up more info before I start. I have it all covered up right now and it is piled under snow so I can't easily look right now. As far as the transom, the wood that is on it is probably original and needs to be replaced. I shouldn't have much trouble figuring out how to do that part it seems to be pretty straightforward as it is just riveted in place. I will try to update later on when I do actually start any work but as I said, it will not be for several more months at least due to the weather and my lack of a proper place to perform the work. Again, thanks to all who replied I appreciate any knowledge you guys are willing to pass along.