Aluminum boat seams

I bought a 12' aluminum boat this fall and I've been tinkering with it a bit since I haven't had it out this winter. It was in great shape when I got it(I thought) but it had a bad paintjob on the inside. I bought some paint stripper(aircraft remover) and started removing the ugly paint. The seams in the front and the two corners where the transom meets the sides of the boat had some epoxy in I really wish I had left the ugly paint alone..

I'm thinking of brazing the seams with HTS-2000(or durafix, alumaweld, etc...). If your not familiar with this stuff, it melts at 730 F and is like soldering or brazing a copper pipe...aluminum melts at 1000 F.

I just thought I'd check here to see if anyone has any input on leaky seams or brazing aluminum....right now the biggest obstacle is removing the old epoxy from all the nooks and crannies. I tried easy-off oven cleaner today but it made the aluminum turn white and I worry about it weakening the already thin hull...The epoxy is grey and softish so I think it is the type sold as aluminum epoxy..

Thanks for your ideas.......
Here's HTS-2000's demo video....looks like pretty cool stuff

You could leave the epoxy alone and ad a new seam of guttersealant over the epoxy to make a new seal we it may have leaked before. Just use some masking tape and make a nice bead along the seam. then use a small spreadder to push the bead down and along the seam. pull tape and let dry. Thats my plan but also needs some new rivets along the floor.
I remember in high school a decade ago we built an aluminum boat in welding class. We used some kind of hardened foam, I dont remember much about it I was 90% of the time under the influence lol but I quit all that after high school. My job was the fabrication of the metals used before I got kicked out of school that year. But I do know there is some form of hardened foam that seals the inside seams and is waterproof :( sorry I couldnt be more helpful
I think the also used rubber in the past but you would be looking at having to take the boat apart and rivet it back together.
Thanks Guys,
I'm pretty set on the brazing idea....seems like a more permanent solution. I think I got it figured out...The two back corners(transom) are the tough ones because the seam has crumples from the curving shape...the little crumples are filled with epoxy that will be tough to clean I figured I'll just braze those two from the outside(much tighter tolerances). I bet once I heat the seams for soldering...the epoxy will just fall out. It's not designed to handle high temps like that.

If my test welds go badly, I'll probably try the cabela's has some great reviews, unfortunately it looks like green crayons......

If any one here has a propane torch, or mapp gas...with a wide tip(bernzomatic t4000 or t8000), I'd like to have one to try for a day or two....I have a glass blowing torch but it's really too big for the job...a victor or national would be better(If you've got one to let me try let me know!!!)
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Outdoor Myers,

Maybe if you took a rip, you'd remember the name of that foam stuff....:think:

If you're right about there being a rubber gasket sandwiched in the riveted seams, I'm gonna have a problem(I'd have to weld em' all). I guess I'll know when I see the black smoke.

Can anyone confirm Thuggin's point (that some riveted boats have rubber gaskets inside the seams)? Doesn't matter much anyway....I estimate this boat is 30-50 years old (or older) so the rubber must be toast by now.....
I reset some rivets and put some new ones in then gutter sealed followed by a fiberglass cloth and resin on an 60's 17' areocraft last winter fter my buddy cleanded up the seams and scrapped out the failing rubber. he called it butal rubber. My boat has some you can see along the transom seam come over sometime take a look.
I tried HTS-2000 on irrigation pipe. Overall I'd say it sucks. I used the stainless steel brush and did everything by the book but it din't stop the leaks. Of course the pressure on your boat won't be 60psi.
OK Peeps,
After a ton of research and talking to a welder I discovered that any solution using heat won't work! Thuggin was spot on about the sealant in the seams..Cabela's stuff would cause the same problem.....

I hit a boat repair forum and the general consensus was that a product called Gluvit by marinetex is the best epoxy for the is thin and will penetrate the seams....and is supposed to be flexable which is important.

The downside is that it has no UV protectant so I'll have to paint the inside of my hull..

Hey Thuggin, We should go in on some and some good paint too......I also saw a quick fix for your squirting rivet hole...just clear the hole and insert a stainless nut and bolt of the appropriate size. You could use rubber washers if you want too. That should get you going in just a few minutes......but I will be buying gluvit and paint very soon(this week) so get back to me....I can cover you if you want to get in on it. I don't know what you meant by "gutter sealant" but I think this stuff is better. Here's a link to a cool rebuild of a valco like your's(unfinished). Don't pay attention to the decking....but imagine your's with fresh paint and no leaks...and look at the shine he puts on his!!!!

12' Valco Project w/ pictures - Page 2 - iboats Boating Forums
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Never use aircraft remover on your boat! It is designed to destroy paint and is hard to get rid of!!! I'll have to scrub out the whole thing with zylene, acetone, laquer thinner, or the like............this job he turned into a big pain....
the proper thing to use is a bead of 3M 5200 Marine adhesive sealant in gray . there is a buytal ruber gasket between the rivets and the hull... do not braze the seam you will damage the seal and possibly the hull depending on the alloy it was built with.. after the seams are addressed you can coat the hull if you like with gloveit or other epoxy but isn't necessary..
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Thanks for the tip about the 3m stuff, but that's a little old school...Gluvit is the way to seal an aluminum boat. So says the people at the boat repair forum where I have moved this rebuild thread:

Another thread about painting aluminum! - iboats Boating Forums

If links to other forums are frowned upon here, feel free to delete this....but if you want to follow my progress on the sealing and paint, I've posted some pics there......
glovit is a coating 3m is the sealer UNDER the coating..... need both... because if you hit somethingand damage the COATING you need the SEALER to keep the inside of the hull dry... glovit is a film coat and doesn't fix the initial problem,, seal the original problem THEN protect it with the coating...
Gluvit says right on the can that it "seals leaky seams and rivets". The school of thought that I am operating under is that Gluvit's long working time is intentional, so that it can flow into the seams and rivets. I plan to tip the boat several times during application so gravity will pull it deep in there! I can see nothing on the can that implies that it would be compatible with 3m epoxy but marinetex does make a filler putty to use on larger repairs, before applying understanding is that gluvit should be used on bare metal and this product only......

By the way, boat builders are using gluvit to seal brand new drift boats(koffler in eugene for example)

I think the grey epoxy that crumbled out of the boat originally may have been aged 3m......
the mfg are using Gluvit as a PROTECTANT not a sealer... the gluvit coating acts as a barrier coat that is more flexable therefore more impact resistant to sharp objects, than the base aluminum... it also peels off over time and no it does not flow into cracks it seals OVER them.. take a look at the link in my signature... loose rivets and seams should be fixed FIRST then SEALED over for protection. the long working time is to ensure smooth finish and coverage of larger areas and to get a better stronger cure. you are free to repair your hull any which way you feel is best, it just isn't how i would do it.... and as for the old grey sealant... it may have been a 3m or sekaflex product, but i doubt it was 5200 or anywhere near the new adhesive sealant's on the market quality... technology has come along ways... ive seen 5200 carry an 18" engine setback bracket with 540 lbs of engine on it and not budge loose i know this for a fact because i personally witnessed the fact the top 2 engine bolts were sheered off. and thebottom ones were loose but the engine and bracket never moved
Not trying to say that I know more than you, this is my first boat and first time sealing a boat. I am saying that what you're telling me is contradicting what others(from the boat repair forum) told me and also what's on the Gluvit can. Here's some direct quotes from the can: "seeks, fills and seals hidden leaks, cracks", "waterproof epoxy SEALER","seals leaky aluminum seams,rivets...". Actually you contradict yourself a couple times here by saying "Glove it is a coating not a sealant" then saying "repair with 5200 then SEAL with gluvit". Also you said"after the seams are fixed you can coat the hull if you like" and then said "...need both"(5200 and gluvit). I fully understood what you were trying to say regardless so no worries..

That being said, a lot of people have suggested using 5200(by itself) and if my boat still leaks I will use it on the outside of the hull. I don't think I have any leaks on rivets not associated with seams....the boat probably doesn't leak much at all, I'm just trying to repair any damage to the seals that I caused while chemically stripping paint....

I didn't see anything on your website about hull repair, judging by what I saw, I'd guess you are more a mechanic than a body work guy, but as I said you obviously have some experience with boats....I'll run your suggestions by some other people to see if anyone agrees with you....Too bad you're not in eugene, you could give me a good deal on some work and prove your point!

By the way, Thanks for sharing your thoughts and experience.....and WELCOME to the forum!!!!!
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Hooked Up
I'm going to recoat my DB for my 1st time. It has remnants of I assume Gluvit in places. How did your recoat project go? Any advice on what to or more importantly not do :) would be greatly appreciated.
Before you use Glovit you much check out a product from Wetlander. Just put that into any search engine. I had Gluvit on the bottom of my Willies and it's a pain to apply and does not last long running our shallow rivers here in the Northwest. I put this stuff on the beginning of the year and it's awesome. The first application is time consuming because I had to take all the old Gluvit off but now all I have to do is lightly sand what's on there and apply a new top coat. It will seal the cracks and small leaks. After I mixed the solution I applied it with a foam roller and there was enough solution that I have a 1/4 inch layer on the bottom and chines. No only is it durable but it's slick. I can hold in water that I could never had achored before. The first time the boat flew off the trailer. I have problems beaching for lunch because it wants to slide back into the water. You absolutely must take a look at this product, it's tougher that Gluvit or Coat it, it's flexible, it's durable and unbelievable slick. It will seal the pin-hole leaks in the seams and it comes in any color you want. If you decide to use this product you will not regret it. But if you do let me know and I can give you a few tricks I learned to make your job go easier.

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