Sealing a hull

[bassin17]

This site is exactly what i was looking for. Thanks in advance! I have a 16' semi v jon boat that leaked like a sieve when I first bought it. I put it in the water and tried to find all the leaks and marked them, but it got to the point that there were to many. Instead I used NP1, which is a polyurethane based sealant, and caulked all the rivets, seams, and screws from the inside and out. Now, 4 years later I am doing a complete overhaul. New floors, decking, transom... the whole 9. I wanted to know how to make it as water tight as possible. I don't want to have to take the floor up again. Is there anything I can spray in the bottom over all the NP1 I already have in there? I bought some of the bostik 920, but I would think with all the synthetics on the market something has to exist I can coat the inside with that will seal it. I have heard the spray in bedliner doesn't work, although that was my first idea. Thanks for any advice!


As an aside... I didn't know about the treated lumber deal. Should I not use it to rebuild my transom and use it for my floor and decking?

 

[Brine]

Look up GLUVIT. Call the mfg and check if it can be applied over your sealant. Take into consideration, you would apply it to the rivets and seams, not the entire bottom of the boat. Measure it out, and you'll probably find a quart will do it.

Treated lumber shouldn't be anywhere in an aluminum boat. Get a good exterior plywood and seal it yourself. If you go through the mods, you'll see lots of this being done.

 

[bassin17]

Thanks a lot! What do you mean by a good exterior plywood? Is that not treated? How is it different from regular plywood?

 

[bassin17]

I don't think I have ever spent more time on a single web site in one night as I did last night. I have learned so much here its incredible! Now that I have a better idea of what I am going to do, I have another question. Is it better to use gluvit or steelflex to seal my leaks. I don't really need the "slickness" from the steelflex but I get the idea that it really seals everything out. Also, it would be a lot less work to do the outside in steelflex than the inside in gluvit... also cheaper from what I have read. Thanks for all the info!!!

 

[crazymanme2]

Whats even cheaper yet is to rebuck those rivets.Most rivets just need to be rebucked & no more leaks.I've helped a couple people rebuck there boats & other than a couple here & there that had to be replaced no leaks.

 

[russ010]

I like gluvit more than steelflex... especially below the waterline.. and a little easier to work with than steelflex. You do need to paint it after you put it in though

check this out - https://www.marinetex.com/gluvit.html#Anchor-Directions-14210

 

[bassin17]

When you are talking about rebucking the rivets, what do you mean by that? And how do I go about checking to see which rivets need to be done?

 

[crazymanme2]

Do a search on rivets or bucking rivets.There's been plenty of post about it.To see what ones are leaking put a SMALL of water in boat & mark leaking ones.

 

[Nussy]

Bucking rivets means access to both sides of the rivets...thus removing the floor. It's the best way to seal the leaks...thats for sure. Having used Steelflex on both my builds I'd go that route. I've not used Gluvit to have an opinion of it.

 

[russ010]

Having used Steelflex on both my builds I'd go that route. I've not used Gluvit to have an opinion of it.

main difference between the two - Gluvit is to be applied inside the boat; steelflex is made for the outside

 

[bassin17]

Thanks for the tips... I have read a lot about steel flex on this site and realize the difference between that and gluvit... but which one holds up better with the flex of aluminum. Also, what is the best way to get all the polyurethane sealant off the existing rivets and seams of the boat? I need to do that before I can figure out what rivets are bad. I was thinking a whiz wheel or wire brush on the end of a drill. I think it would significantly less work to do the steel flex on the outside but I am a little concerned about a post I saw on here where a missed rivet was bad and the steel flex cracked. However, I have not read any reviews about gluvit on here where guys have used for any period of time. I've been through just about every gluvit forum using the search function. And by the way.... this site is addicting.