What should I do to hip up my 12' aluminum boat?

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its old school rivetted seams. Someone in its history epoxied the seams, then painted it. I like the look of an old rivetted alum boat, so I stripped the paint off.A lot of the rivets are loose. Probably why it was epoxied. There are dents that penetrate the hull. And I would like to reinforce the seams with weld. Its a 22 gauge material, so I know I already need to use a TIG setup. Which I dont have. I am experienced stick, wire - gas and fluxcored, and oxy fuel welder. Ive never used TIG, but will learn it. So should I buy a machine? what recommendations would you make? Can I rent a machine?any other ideas?
Reply:It has riveted seams?  Like lap jointed and riveted? If so, you aint gonna weld that joint easily.  As in heat, brush, heat, brush, heat, brush, on and on until you boil out all the accumulated funk from between the plates. Re-buck the rivets and squirt some epoxy on the seam. By the time you weld an old boat like that you could have bought a new one.Two turn tables and a microphone.
Reply:All I can say is don't even think about that.  Even if the boat was perfectly clean, new metal (which it's not), and it didn't have any kind of seam sealer (most tinnies do from the factory, coupled with whatever has been added), just the weld distortion would curl that boat up like a tater chip. But, you have years of corrosion, which will make any TIG welding tough, as well as seam sealer, which will make any TIG welding impossible, on top of the distortion issue.  Lastly, you certainly aren't going to be TIG welding thin aluminum right off, after buying a TIG machine.  The oxy-fuel experience will help, but aluminum TIG is certainly a different animal, so renting one for a month will get you nowhere, and while buying one may not be all that bad, don't buy it with intentions of using it on this particular boat.  Certainly not the right tool for the job.Get you an air hammer from somewhere, a rivet set from Aircraft Spruce, a bag of solid rivets from Grainger, and a tube of 3M 5200 from a marine store if you want to properly fix that boat.  Rebuck some of the loose rivets, and replace the rough ones.Who is John Galt?
Reply:bassboy gave some great advice. i have professionally welded on al boats, and dealing with seam sealer is very time consuming.Dynasty 200DXPassport plus w/ spoolmate 100victor 315c oxy/(act and prop)Miller digital elitemilwaukee power tools
Reply:thanks for the replies. This is why I asked the experts. It did feel like I was missing something, and the corrosion and seam sealer would have been part of that. rebucking rivets...? I may have to contact some of you offline to get more details. Thanks!
Reply:Originally Posted by tenpinsthanks for the replies. This is why I asked the experts. It did feel like I was missing something, and the corrosion and seam sealer would have been part of that. rebucking rivets...? I may have to contact some of you offline to get more details. Thanks!
Reply:Seriously,If the boat is in that bad of shape, your best bet is to "recycle" it as a flower pot and go down to the local Bass Pro Shop and buy yourself a new john boat.Re-riveting and caulking an old, corroded  aluminum hull will prove to be an exercise in futility.  You'll be "chasing" leaks til the cows come home.  You'll never "break even" even if you only figure your labor at $8.00/hr.Don't even THINK about welding it.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:1-'tightening' up old rivets does a great job of making hairline cracks2-replace the rivets by drilling out, reaming to oversize and using oversize shank rivets3-the previous advice on bucking, how-to, etc. is critical4-any riveted, light gauge boat I've seen--always has rubber sealing strips in the lap joints5-if the lap seam integrity is compromised at any point along it--it will leak,requiring sealant along the entire lap length--easier said than done6-SundownIII's comments are applicable7-Tig welding can be done (not a beginner's job)--but it can easily melt the lap sealing rubber strip--then requiring full lengthBlackbird
Reply:Originally Posted by dave powelson1-'tightening' up old rivets does a great job of making hairline cracks
Reply:Originally Posted by bassboy1To a point, but in certain situations, it can be just the ticket.  It's all a matter of how bad the existing riveted joint is.And Sundown is probably right on the time consumed, but on the other side of the ticket, a lot can be learned from an exercise in futility.
Reply:Originally Posted by PangeaIf SundownIII tells you something about a boat, you can bet the farm on it. He is a grumpy old sour phart but he has lots experience with nautical applications.
Reply:bassboy,Know what you're talking about when it comes down to $/# for fish.  You think that's bad, try offshore sport fishing.  When I was fishing the east coast tournaments on a regular basis (late 80's-early 90's), I was running a 50' Bertram sportfisherman with T-8V92 Detroit Diesels (735 HP per side) that burned 68 GPH at cruise.  That's back when we were paying .68/gal for off road fuel.  Every time I left the dock to run to the Norfolk canyon (about 75 miles), I figured I was throwing a $1,000 bill on the dock.  I ate a lot of tuna back in those days.  We did donate a lot of tuna to a local orphanage, so we got a decent tax writeoff there.The reason I made my comment about the aluminum boat is simply based on experience.  Most riveted boats, by the time they reach the state described, have many other "issues" that may be totally unseen to the casual observer.  Most of the time we're dealing with "metal fatigue" which has no viable repair other than replacement.  The seam sealer has hardened and no longer performs as intended.  Neither of these involve "reasonable" fixes.Just seen too many cases of where one man's "labor of love" turns into an "exercise in futility".  I tell people we buy/own boats for recreation not frustration.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Originally Posted by SundownIIIIf the boat is in that bad of shape, your best bet is to "recycle" it as a flower pot and go down to the local Bass Pro Shop and buy yourself a new john boat.
Reply:To clarify, there is no corrosion per se. Just normal oxidation. The advice on the difficulty trying to TIG that, combined with knowing now (and I can see it now that Im looking for it) that there is a rubber-ish gasket in between the plys of the joint are much more valuable than anyones suggestion that its not worth my time. Even for 8.00 an hour. Which I havent made since I was in Jr High. An old chochski I saw in a beach house once - "Nothing is as satisfying as simply messing about with boats".So yeah, its a hobby. And on this hobby - which I mentioned before - it has an old school cool look with the rivets and cleaned up aluminum. So I'll keep this one. I dont know how messing about in your garage can be equated to work. I appreciate the advice and links on rivetting! Very helpful. I did score an air hammer yesterday at a pawn shop for 4 bucks. Looking forward to getting in the water sooner than I had anticipated.on edit: I did a leak test this week by putting it on supports and filling with water. No visible leaks after 2 hours. Still going to redo the loose rivets and run some gunk down the keel. I know still water isnt the same as when the boat is underway, so that seems reasonable work to put in .Last edited by tenpins; 02-27-2011 at 11:09 AM.Reason: Additonal
Reply:tenpins,I built boats in welded aluminum so the boatworks would be a place folks with riveted boats would come for repair.I did weld some of them but found the hull seam results to be worse than bassboy, Sundown and the others have mentioned.  TIG worked fine for the transom corners, gusset cracks, bow stem repair of the castings and fittings, but hull seams aren't the best place to weld.Not only do the seams have a sealing strip, old or not, and not only is cleaning the inner surface of those seams "impossible" (without disassembling the boat...) but the resulting welds have an effect on the hull that is not mentioned yet; flex versus stiffness.Riveted joints are more rigid (up to failure) than welded aluminum which has more flex. These boats are not designed to flex in the way that welded boat are.   The result is cracks in places where the riveted boat does not regularly crack for many years.I looked at the first repair, decided to try, and then welded a small seal strip along the edge of the bottom to the topsides seam.  (I use a cold wire fed TIG torch using 0.025" and 1/16" tungsten and the beads can be small enough to "make the weld").  The boat went out and in a few days leaked.  I guaranteed my work so I welded some more....this happened a few times... so; I finally bought the little skiff (cheaper than welding on it for free forever) and did what SD advised.  I let a friend plant potatoes in it- "raised bed planting" they called it.The first few welds just leaked at the ends when the heat hardened rubber filler powdered away. Then I welded across a bottom frame (press formed thwart riveted into the hull seam joint from inside) and the next cracks were fore and aft that frame end along the bottom and topsides panels.  Chasing cracks, lengthening welds to 'fix' what the caused, fiddling and wasting time.... on it went for about 10 days.  Every other day or so the owner would faithfully show up with his little boat and I'd stop work and give it a go.  If you can avoid welding hull seams, it appears to me that you'll be ahead.TIG welding just cuts, holes (punctures), worn spots from dragging and non-hull seam works OK, but welding thinner material (<0.100") does take a bit of practice.cheers,Kevin Morin
Reply:Originally Posted by tenpinsTo clarify, there is no corrosion per se. Just normal oxidation. The advice on the difficulty trying to TIG that, combined with knowing now (and I can see it now that Im looking for it) that there is a rubber-ish gasket in between the plys of the joint are much more valuable than anyones suggestion that its not worth my time. Even for 8.00 an hour. Which I havent made since I was in Jr High. An old chochski I saw in a beach house once - "Nothing is as satisfying as simply messing about with boats".So yeah, its a hobby. And on this hobby - which I mentioned before - it has an old school cool look with the rivets and cleaned up aluminum. So I'll keep this one. I dont know how messing about in your garage can be equated to work. I appreciate the advice and links on rivetting! Very helpful. I did score an air hammer yesterday at a pawn shop for 4 bucks. Looking forward to getting in the water sooner than I had anticipated.on edit: I did a leak test this week by putting it on supports and filling with water. No visible leaks after 2 hours. Still going to redo the loose rivets and run some gunk down the keel. I know still water isnt the same as when the boat is underway, so that seems reasonable work to put in .
Reply:i have several friends that always carry marinetex for repairs, you can fix anything from a scrape, to a moderate hole (backer needed for large holes) and repairs are permanent and seaworthy.http://www.marinetex.com/Dynasty 200DXPassport plus w/ spoolmate 100victor 315c oxy/(act and prop)Miller digital elitemilwaukee power tools