Pitted aluminum hull

Discussion in 'Boat Modification Journal' started by Katfish Kern, Jul 28, 2009.

  1. Katfish Kern

    Katfish Kern New Member

    Messages:
    251
    State:
    Florida
    I got my hands on a 17' aluminum hull. The only problem is that the boat has been in salt water, and there are 4 corrosion marks on the starboard side. There is the begininng of a hole to start. They are about the size of a #2 pencil lead. The holes are not all the way through the hull. What is the best way to fix, and patch these areas, without making the hull look terrible?? Thanks for the help in advance.:0a22:
     
  2. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Good luck.
    I wouldn't make it a project boat or dump much into it.
     

  3. DANZIG

    DANZIG New Member

    Messages:
    6,672
    State:
    West Virginia
    "Marine-Tex" perhaps?
     
  4. Katfish Kern

    Katfish Kern New Member

    Messages:
    251
    State:
    Florida
    The spots are not that big... as a matter of fact they are hardly noticeable. Is it still to late to fix it?
     
  5. Katfish Kern

    Katfish Kern New Member

    Messages:
    251
    State:
    Florida
    Will that adhere to aluminum for a long period of time?
     
  6. stoney53

    stoney53 Well-Known Member

    Messages:
    1,380
    State:
    PA
    if you know someone that welds aluminum ,that might be the way to do it, not sure if there is any type of patching material that would hold up long term
     
  7. on_the_fly

    on_the_fly New Member

    Messages:
    606
    State:
    Kentucky
    yor going to have to clean it realy well with a stainless steel brush (preferable one on a grinder- does way better job than by hand) then tig weld it turning your cleanign up a little higher than usual. I would use a filler like 4043 its a little softer and easier to work with than the 5356. if you did take it to a welding shop you are probably looking at 60 to 80 bucks an hour but if you do the prep work and have it ready for them to preheat and weld then they might cut you some slack and do it for 40 or 50 bucks.
     
  8. Magnus777

    Magnus777 New Member

    Messages:
    30
    State:
    Arkansas
    Harbor Freight sells low-temp "Alumiweld Rods"...basically a low working temperature allow that you can use with a small propane torch. I bought some for doing the same thing, patching pits and small holes in an old aluminum boat. It works pretty well, and is plenty strong enough...just don't keep the heat on the hull too long, or too long in one spot, because once you start thinking you've got the aluminum too hot, and maybe it's time to back off...it's already too late. But that shouldn't be a problem if you're careful, and keep the flame moving, because this stuff melts at a much lower temp that the aluminum in your hull. Once you've got the patch in place, come back with a disc sander or whatever you've got and clean it up. It'll look almost as good as an aluminum weld, and work just as well for what you're doing.
    This stuff is called "Alumiweld Rods", and it's sold by Master Marketing Products, 3731 Oak Ridge Dr., Sebring, FL 33876. Their phone number is 863-655-1750, or 941-758-8555. The rods come in packages of 10 or 12, I think, and look just like a pack of brazing rods, except they're aluminum. Cost about $12 from Harbor Freight. (Not sure if I'm allowed to put their company name and info in the post, so I apologize if I screwed up...but hope this helps.)

    J
     
  9. screamnclickersc

    screamnclickersc New Member

    Messages:
    755
    State:
    S.C.
    You can fill it w/ Bondo or epoxy.
     
  10. MiseryMike

    MiseryMike New Member

    Messages:
    544
    State:
    Blue Springs
    if it was me id go to a auto store and buy some JB Weld its a epoxy of sort i used it on the old super coug on the radiator dont see why it wouldnt work for wut u want 2 do.
     
  11. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    The problem with these rods are they are primarily zinc not aluminum.
    Zinc will corrode out. Just like the replacement zincs on an outboard.
    Not only that but you further contaminate the aluminum from welding.

    These rods are solder. Nothing more. Anything that flows under 750 degrees is considered soldering.

    If you do use them. PRACTICE on something else. It's not hard to oil can the crap out of aluminum if you heat soak it.

    I bought 2 pounds of those rods and dicked around with them quite a bit.
    They may be ok to fill a hole in an aluminum railing on a pontoon boat but nothing below the waterline in my opinion. Definately not for structural repair of any kind. It's solder.
     
  12. on_the_fly

    on_the_fly New Member

    Messages:
    606
    State:
    Kentucky
    I agree fully with mark on that. and being a welder and dealing with peoples cheap fix epoxy's I am dead set against them as well yes they all do work but they are all a TEMPORARY fix and only make future welding repair more of a hassle to clean up.
     
  13. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Been shopping a Millermatic 211 with a spool gun. My next toy to add to the shop.
    I figure building boats I need to build trailers to put them on.:big_smile:
    Cut out the middle man and the middle middle man.
     
  14. Magnus777

    Magnus777 New Member

    Messages:
    30
    State:
    Arkansas
    That's a very good point, Mark. I see how the zinc in the solder would quickly corrode, and it would make a more permanent repair much harder later on. Aluminum welding is definitely the correct repair method. However, is corrosion still an issue with a non-powered boat such an aluminum canoe, or row boat with no electrical system? What about if the repaired area, the whole deck and hull for that matter, were coated over with a sealer such as epoxy paint, or truck bed coating? That would, of course, add cost, labor, and weight to what KK may have hoped would be an inexpensive fishing boat project...in my case however, I only paid $50 for the boat, and a good coating of bedliner and/or paint seems worthwhile, being as the increased durability through a few fishing seasons would be desireable.
     
  15. on_the_fly

    on_the_fly New Member

    Messages:
    606
    State:
    Kentucky
    mark their nice I cant speek for the 211 but we bought a Millermatic 250 and a spool gun and also have the millermatic syncrowave 250 stick and tig with the water cooled torch. the mig we bought about 7 years ago now and at the time it was the smallest modle that still had the LED display. the spool gun we bought 1 year later and that alone was 900.oo bucks.
    if you are looking to build trailers why the spool gun? running regular steel wire you can run the bigger wire spools and the wip will allow you to get in tighter spots. I only use the spool gun for running aluminum just for the fact of aluminum wire is to soft to run through a 6 foot or longer linner.
     
  16. Katfish Kern

    Katfish Kern New Member

    Messages:
    251
    State:
    Florida
    First of all, thanks for all the input fellas! The spots are on the starboard side, well above the water line. Do you think if I sanded the spots down, and taped them off, I could use some JB Weld?
     
  17. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    I've always got something going on.
    I want the capability to weld some aluminum and stainless even if for prototype purposes.
    Pontoons, tanks, grills, rod holders, etc.

    My latest project was an aluminum beach cart. I sure could have used a spool gun.
     
  18. Grimpuppy

    Grimpuppy New Member

    Messages:
    3,556
    State:
    Concordia, KS
    I have the MillerMatic 210 with a spool gun. The predecessor to the 211. The spool gun is 10 times as fast for welding aluminum, but the weld appearance is no where close to being as nice as TIG.

    As for the boat, I would take it somewhere an have them glass bead blast the pits before you do whatever repair you decide on. If you don't get all the corrosion out, it will keep corroding under the repair. Kind of like putting bondo over a rust hole.
     
  19. StuBone278

    StuBone278 New Member

    Messages:
    625
    State:
    south central Louisiana
    Just a quick question. I run my boat in a fair amount of salty and brackish water. I usually rinse the boat off a little after getting home, as well as flush out the outboard. My question is will my boat be safe from corroding as long as I have the zinc anodes on the outboard in good condition? I know that's what they are supposed to be there for, but should I take other precautions? Thanks.