Help with Aluminum Pin Hole Repair

Discussion in 'Boat Repair Help' started by catter62, Feb 26, 2008.

  1. catter62

    catter62 New Member

    Messages:
    153
    State:
    texas
    Anyone know the best way to repair a couple small pin holes on a jon boat? They are back by the transom below water level. The aluminum back there seems to be a lot thinner. I have tried JB Weld and a couple other epoxy but none lasted long. Thanks for any help!
     
  2. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    Best bet is to take it to a shop that does aluminium welding. They may have to replace a large piece. It sounds as though that aluminum has just about had it, and I don't think there is really anything you can put on it that will last.
     

  3. whisker maniac

    whisker maniac New Member

    Messages:
    2,712
    State:
    arkansas
    cabelas carries some type of aluminum boat repair. You can check that out on their website.
     
  4. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Use some 3M 5200 or some 3M-4500 which is the faster cureing of the 2 but beware let it dry completely before putting back in the water.
     
  5. cantstopgrandma

    cantstopgrandma New Member

    Messages:
    955
    State:
    MD

    If i'm not mistaken, the difference between 5200 and 4200 is that 5200 is MORE permanent. Both can be had in the quick drying formula. From what I hear, 5200 is there almost for good once it cures. 4200 requires less chisel and hammer work to remove. Make sure you get the quick dry, or it will take forever to dry and cure. It costs a little more but is well worth it.

    After some research, This is what Boaters World has to say about the 4200:

    A polyurethane adhesive/sealant that is very similar to 3M Marine Adhesive/Sealant 5200, but that is about half the strength, which allows for disassembly of parts. 4200 delivers flexible bonds with good adhesion to wood, fiberglass, gelcoat, certain plastics, and metals. It is paintable and sandable, and forms watertight, weather-resistant seals on joints and boat hardware above or below the waterline.

    If you do decide to go this route, I would scuff it up a little with some sandpaper to remove any dirt and give it something to stick to, then wipe it off with paint thinner or some other kind of painting prep. Should make for a more permanent fix.
     
  6. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    You can always try the HTS2000 rods.
    They work but watch your heat.
     
  7. catter62

    catter62 New Member

    Messages:
    153
    State:
    texas
    Thanks everyone! I think I'll give the 3m 5200 a try first and see if that does the job.
     
  8. chambers bd

    chambers bd New Member

    Messages:
    1,134
    State:
    Sautee,Geo
    Top wise said add a plate to the back, welding. If you want you can try the 3m 5200 after ward try some paint on bed liner, Im sure a spray can 7.00 wally world will cover that much.
     
  9. brewfish

    brewfish New Member

    Messages:
    61
    State:
    fl
    The importance of watching your heat can not be over stated. There's not many things worse than watching part of your boat disenagrate like ashes.:crazy:

    I tried patching a couple of little screw holes with some HTS recently. The only thing I accomplished was burning a nice hole into my boat. This was on the rub rail which I believe is a thicker than the rest of the hull so i can only imagine how easy it would be to mess up in an even thinner area.

    I would defintley try the 3M first.
     
  10. DCcatfisher

    DCcatfisher New Member

    Messages:
    136
    State:
    North Carolina
    The only downside to using the 3M sealant is that if it doesn't work or it fails in the future, then if you take it somewhere to have it welded you have to remove all that junk before you can weld it. Aluminium has to be extremely clean, free of all grease, oil, paint or any other chemical or foriegn material before you can even begin to try to weld it. Trust me I have welded alot of aluminum (welding is my profession), both fabricating things from new material and repairing things that have broken, and I have seen almost every kind of patch up job people has tried to do with glues, epoxys, sheetmetal and pop rivets, and just about any other thing you can imagine and I have never saw one that was a permenant fix other than welding. All of the epoxys jobs I have saw worked fine until the application was actually put into use as it was intented to be used and then with a little time and vibration and other stresses from normal operation the sealant/epoxy/adhesive will almost always fail because there is no penetration into the base metal. It is exactly what it claims to be, an adhesive. There is always an exception to the rule and you may be it and it may work perfectly for you, but speaking from more than 10 years experience in the welding industry much of which I spent in a small hometown welding shop repairing things such as you have described here, I think you will be better off going straight to the welding shop. Good luck and let us know what you decide to do and how it works out.
     
  11. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Yea, brand new aluminum stock can be a pain to get clean sometimes.
    Even using acetylene (a gas) on aluminum will contaminate the crap out of it.
    Heating aluminum changes the molecular structure of the metal allowing the gas into the heated metal. It'll be there forever.

    Aluminum welding is the best way.
    If its an old jon boat with years of contamination in the aluminum you'll probally be better off with aluminum rod. Its not so finicky with clean.

    Strike an arc on a contaminated aluminum boat bottom and you'll be chasing a hole halfway across the hull trying to get it filled back up.

    Thats why I not big on coating aluminum with things like truck bed liner.
    You ever hole it chances are you'll be stuck with temporary patch jobs as long as you own the boat.
     
  12. riverbud55

    riverbud55 Well-Known Member

    Messages:
    2,932
    State:
    AZ Topock-/CA Riverside
    Name:
    Dale Miller
    i'll 2nd what DCcatfisher had to say, jb weld and the like are all patches and are NOT fixes or repairs, we charge $75.00 an hour, and if ya bring it to us with what ever spread all over your paying us to clean all the junk out of were the weld is going to be and if its down in holes/pits and crevices its going to be hell getting ready to weld, if it were me i would put a complete new pc alum to cover the trasum from edge to edge and from the bottom to at least 4" or 5" above the water line and weld it completly around, if the pc of alum were precut to fit and was ready to weld up (cleaned with s.s. wire brush were the weld is going to be, no paint ect.) it wouldn't take much over an hour to weld up, should be able to get a pc of alum for $30+ or -
     
  13. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Any one ever try to make a mountain out of a molehill.
     
  14. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Some would be surprised what would work for awhile.
    My jon boat had a crack in a rib. One piece of duct tape on the outside of the hull about 3 times a year fixed it.:big_smile:

    I eventually got her welded up.
     
  15. cantstopgrandma

    cantstopgrandma New Member

    Messages:
    955
    State:
    MD

    Thats funny, i've used duct tape before too!!! We got to the lake and put the boat in the water, i realized that we were taking on water, luckily still at the boat ramp. beached the transom of our 12' aluminum boat and come to find out, one of those aluminum puttys we used to patch a hole in the floor had come off (granted, it lasted about 10 years or so). We were 30 minutes from home, so a little duct tape slowed the leak long enough to fish all day. I think we ended up using more of that putty to fix it again. We figured if we gotta do it every 10 years, thats still pretty good.
    What did people do before duct tape?!?!?! :cool2:
     
  16. Stubby

    Stubby New Member

    Messages:
    208
    State:
    Kansas, Ar
    JB Weld WILL hold if you clean & Scuff the area around the holes..I've never had one leak or come off after fixing it. and I also can weld alum. it's just to much easyer to JB Weld it.