Crack in my aluminum jon boat

Discussion in 'Boat Modification Journal' started by smhmc6, May 2, 2008.

  1. smhmc6

    smhmc6 Member

    Messages:
    744
    State:
    Kansas
    I noticed today that I'm developing a crack in the circular top rail in the back corner of my boat. I have attached a rough drawing to illustrate the location. Actually I have one on both sides, but the one on the left has grown much farther than the one on the right. This is an obvious concern for me because I'm sure that it has grown in a short amount of time. It is probably due to the new rod rack that I bolted onto the two triangular flanges and just the vibrations from trailering. I put the rod rack on about a month ago and I have only taken it out about 4 or 5 times since then. So it is growing kind of quickly.

    My question is if anyone has had this happen to them and how they fixed it or if anyone knows any product that will stop the crack from growing? I cannot weld and from what I've read in other posts, its hard to find someone who can weld alluminum anyway. Besides the crack started at the edge of the weld where it is the weakest, so if I got it welded again it would probably just start a new crack just in front of the new weld. Right now I'm thinking that I'm going to have to get rid of the boat if there is no way to fix it.... what do you guys think, do I have any options?
     

    Attached Files:

  2. JERMSQUIRM

    JERMSQUIRM New Member

    Messages:
    13,145
    State:
    il-waynesv
    i just recently learned from a guy that runs a plastering buisness that to stop a crack drill a small hole at the end both sides of the crack.

    then find someone that can weld that aluminum. thats my opinion. maybe someone else can offer an alternative. JB weld aint gonna fix it. just a heads up.


    look welding shops up in the yellows and ask what they would charge for a 3-4 inch aluminum weld. cant be more than an hours labor and youll be good as new.

    this is what de does when the hoppers for his sprayers crack. drills ends and welds. the drilled hole stops cracking further.
     

  3. jason454ci

    jason454ci Active Member

    Messages:
    1,307
    State:
    Zanesville, Ohi
    I second what Cats said. In my opinion this is the only fix without getting new corner pieces and having the old ones cut out and the new ones welded back in. Most welding shops should be able to repair the cracks for you. It is very important that the crack is drilled at each end to keep it from spreading. When you call welding shops that are able to do it make sure and ask them how they do it. If they don't mention drilling it just move on to the next shop until you find one that will do the job right.
     
  4. Katmandeux

    Katmandeux New Member

    Messages:
    1,618
    State:
    Checotah, Oklahoma
    Jeremy is right on the money.

    That's called "stop drilling", because it stops the crack from propagating. It's an easy fix. The hole needn't be large...about 3/32" or so.

    Use a magnifier to locate the ends of the cracks. There are almost always hairline cracks that extend past what you can see with the naked eye.

    A skilled welder will know how best to make the repair...he may elect to beef up the damaged area.
     
  5. smhmc6

    smhmc6 Member

    Messages:
    744
    State:
    Kansas
    Thanks alot for the advice. The drilling a hole idea sounds pretty good. It may be a little difficult to drill them though. The top of the gunwales is a tube. So the top wouldn't be hard to drill but the other crack tip might be hard to drill. It has worked its way around the tube from the top down around and into the corner. Its kind of hard to explain in words, I wish I had a digital camera:smile2:. Anyway, It sounds like a pretty good fix. I'll have to call around. I've heard that its really hard to find someone who can weld aluminum... is this true?
     
  6. gilmafam

    gilmafam Well-Known Member

    Messages:
    5,466
    State:
    California
    good luck with the fix.... I'm having a prob "seeing what you are saying", but I fixed a crack on the top flange at the corner of my ole 12ft boat by placing a 3/8" thick alum plate on top and bolted that into place....

    finding someone to weld alum.... thats not to hard to find.. but someone who can weld it with all the "sfuff' in the cast alum... thats the hard part to weld....

    good luck.... bayrunner ray
     
  7. smhmc6

    smhmc6 Member

    Messages:
    744
    State:
    Kansas
    Like Ray said, its probably kind of hard to understand what I'm saying. I made another picture that may help. The crack is in the tube on the top of the gunwale. I filled it in black in the picture of the cross section. It goes from the bottom of the tube on the inside and extend about half way around the circumference.
     

    Attached Files:

  8. Gringoloco

    Gringoloco Member

    Messages:
    426
    State:
    Ft. Belvoir, VA
    Name:
    Josh
    If a crack develops a stop crack fix is a bandaid only imo. I would take it to a shop that is good with aluminum welding and have them fill and seal and sand down the bead back to a smooth finish to prevent any leaks that might occur.
     
  9. JERMSQUIRM

    JERMSQUIRM New Member

    Messages:
    13,145
    State:
    il-waynesv
    YA! if your really worried and this is a good boat other than weld there is no fix worth messing with. jb wont hold nor fiberglass reisen. may hold till first wake you hit. then it will pop loose. a welding shop will have no problem doing it. now your buddies may. you need a low temp rig to weld aluminum. most welders will burn it up leaving nothing for the pro to join. thats why you need a shop. they can guarentee that it wont get melted out. if the crack ends cant be drilled tell the shop what ya want to do. thell know. if the concern is worth the ask its worth $50 -$100 to keep it from being fatal to the craft.
     
  10. JERMSQUIRM

    JERMSQUIRM New Member

    Messages:
    13,145
    State:
    il-waynesv
    if your talking about the tube on the top being cracked all the way around then drill out side that aint all the way. other side thell have to just weld to the end of the tube. really no other way that i know will be nothing but a band aid that will fall off.

    yes its hard to find a buddie with a low heat rig. its not hard for a welding shop or metal shop. just tkes a low heat rig witch most dont want because they weld steel.
     
  11. JERMSQUIRM

    JERMSQUIRM New Member

    Messages:
    13,145
    State:
    il-waynesv
    i see what ya mean. still no fix will do much but cover the problem.
     
  12. PeeDee Cat

    PeeDee Cat Member

    Messages:
    351
    State:
    SC
    If U were down here in DIXIE I would weld it for U.
    PEEDEE CAT
     
  13. smhmc6

    smhmc6 Member

    Messages:
    744
    State:
    Kansas
    Yep, thats what I meant. And you are right, nothing else will fix it. I am a little worried that even welding it would be a "band aid." There is actually a weld already right where the crack is. It is the weld that the manufacturer used to attach the triangular brace piece to the tube. The crack is not on the weld, but just in front of it where the material is the weakest due to the nature of welding. I'm worried that even if the new weld fixes the problem for a while that a new crack will form just in front of that. I may have them beef up the tube in some way... I'll just have to see what they can do for me. Thanks again, everyone for the advice.:smile2:
     
  14. smhmc6

    smhmc6 Member

    Messages:
    744
    State:
    Kansas
    Thanks Greg, I appreciate the offer and I'm sure you'd do it right, but that would be one heck of a drive from Kansas:smile2:.
     
  15. jdbuckshot

    jdbuckshot New Member

    Messages:
    16
    State:
    Missouri
    Where are you at in Kansas, i could weld it for you. Im not a great alum. welder, but we could try it.
     
  16. Grimpuppy

    Grimpuppy New Member

    Messages:
    3,556
    State:
    Concordia, KS
    I may also be able to help you out Steve. Let us know where you are located.
     
  17. smhmc6

    smhmc6 Member

    Messages:
    744
    State:
    Kansas
    I'm in Andover, pretty close to the Andover turnpike exit. I still haven't gotten around to calling anyone, I'll probably do that Wednesday and hopfully find someone to fix it before the weekend.
     
  18. kevhead56

    kevhead56 New Member

    Messages:
    62
    State:
    Greenfield, Il
    Ask a good boat dealer who in the area they would take a boat to for welding. They will know who does a good job. Any GOOD weld shop will be able to repair your boat and have you back in the water in no time.:wink:
     
  19. JERMSQUIRM

    JERMSQUIRM New Member

    Messages:
    13,145
    State:
    il-waynesv
    ya be careful. if you get someone without experience the aluminum can just melt away. then you will have a hole instead of a crack to fix,:confused2:
     
  20. Grimpuppy

    Grimpuppy New Member

    Messages:
    3,556
    State:
    Concordia, KS
    Ah, you are down by Wichita. I am sure someone in Wichita can patch & weld it up pretty good. Theres only a kazillion aircraft quality welding shops that would probably do it for you. If you don't have any luck, shoot me a PM if you are coming up here around Milford sometime. We can get something lined up to get it done.