transom rebuild

Discussion in 'Boat Modification Journal' started by jasonminitruck, Nov 12, 2009.

  1. jasonminitruck

    jasonminitruck New Member

    Messages:
    334
    State:
    tennessee
    I have a 1977 duracraft aluminum boat that needs the transom redone. My question is what to use should i have it rebuilt with all aluminum as i can get it done for $250 this way, or should i just replace it wwith wood as it was from the factory, and what are the advantages and disadvantages of each. One more thing has anybody used alumalloy brazing rods and how do they work on boats. Ive used the alumalloy rods on cars and trucks with good outcomes im just affraid to try them on a boat without any reviews on them.
     
  2. DANZIG

    DANZIG New Member

    Messages:
    6,672
    State:
    West Virginia
    Hard to argue with 32 years of service out of the factory wood.

    What are you intending on using the brazing rods for? If it is a rivet problem, fix/replace the rivet.

    On my little tinboat a rivet had pulled through the hull years ago and I just recently brazed it with the hts2000 rod. Haven't had it in the river yet but it seems to hold water fine. I expect it to do better than the JB weld I had in there for years.

    Mark J is not hot on the rods, below the waterline, on account of the zinc content of the rods.
     

  3. jasonminitruck

    jasonminitruck New Member

    Messages:
    334
    State:
    tennessee
    I was going to use the rods to fill in screw holes from where the prvious owner had a transducer mounted.
     
  4. kyelkhunter3006

    kyelkhunter3006 New Member

    Messages:
    1,192
    State:
    Ky
    How thick is your transom? Aluminum is a lighter metal, but if your boat has a transom that's 1" thick for example, a piece of solid aluminum that thick WILL be MUCH heavier than a like thickness of quality plywood. Coat the ply with epoxy and it'll last forever, be lighter, and let your boat perform better too. If you're going to do the work, it'll more than likely be cheaper for the wood/epoxy too.
     
  5. DANZIG

    DANZIG New Member

    Messages:
    6,672
    State:
    West Virginia
    For small holes like that, I reckon I'd just seal 'em with a couple closed end pop rivets with a tiny dab of 3M 5200 in the hole for good luck and call it good.

    I went with the brazing rod on mine on account of the hole being much too large for a rivet, and I don't weld.
     
  6. DANZIG

    DANZIG New Member

    Messages:
    6,672
    State:
    West Virginia
    "Coat the ply with epoxy and it'll last forever"

    Many folks go with a good quality exterior ply to save cash,,, On my Cuddy I split the difference between that and Marine ply and have gone with MDO sign board ply ( bout $60 a 3/4" sheet) and some cheaper, but recommended, true epoxy. Thru hull holes oversized, filled with epoxy/filler mix and redrilled to size.

    Barring a fire or other catastrophic event, I expect more life out of it than I do out of myself.

    If you want extra insurance, and extra strength, epoxy in some fiberglass matt to cover your board.
     
  7. jasonminitruck

    jasonminitruck New Member

    Messages:
    334
    State:
    tennessee
    Thanks for the help so far the reason i was looking at the brazing rods for the hole was the i tried the 5200 sealer, and it lasted untill the last couple of trips this summer and has began to leak a little. The alluminum i was looking at for the transom was 1/8" sheet with square tubing in the center. Once agian i would like to thank you guys for the help
     
  8. DANZIG

    DANZIG New Member

    Messages:
    6,672
    State:
    West Virginia
    Only use the 5200 as extra seal for the closed end pop rivets. :big_smile:
     
  9. jasonminitruck

    jasonminitruck New Member

    Messages:
    334
    State:
    tennessee
    What type of epoxy would i need that wouldn't have an adverse reaction on the aluminum. Sorry for all the questions i've never done this to an aluminum boat before.
     
  10. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    The thing about those rods is it's not brazing.
    The temperature is too low for brazing. It's soldering.

    If you want to fill an old screw hole in the gunnel where you had a rod holder mounted or something mounted once, yea, it's ok for that.
    But for a crack or hole in the bottom, I'll pass. It's solder, nothing more.
    Once you use it and it doesn't work it will be a job trying to fix it with a weld since you've contaminated the aluminum with about 10 different kinds of metals.

    It has it's uses. Just not not on the bottom of a boat.
    I do keep some around though. They have come in handy.

    Another thing. You are sitting there heat soaking a small area on the bottom of hull and you wind up with a huge problem. Major "oil canning" or even burning through the hull. It happens REAL quick and there aint no turning the clock back a few seconds.
    It has a big learning curve associated with it in order to use as advertised.
    I've done quite a bit of brazing. It don't work like silver solder on copper tubing. That is for sure.
     
    Last edited: Nov 15, 2009
  11. fishmonster13

    fishmonster13 New Member

    Messages:
    700
    State:
    cincinnati,ohio
    get a piece of aluminum flat stock drill and tap for your new transducer and use it to cover the old holes use a little 3m 5200 to seal the back side , you can get the aluminum from speedymetals.com they will sell it by the inch
     
  12. DANZIG

    DANZIG New Member

    Messages:
    6,672
    State:
    West Virginia
    "What type of epoxy would i need that wouldn't have an adverse reaction on the aluminum."

    MarkJ you're slipping! As the resident closest thing we have to an epoxy expert, that was a good Q for you!

    As far as I know, there should be no problem with a reaction to the aluminum.

    I am guessing that you can do this work to the board before installation, correct?
    Cut it, Test fit it, drill it, pull it back off, epoxy it, install it,,,, go fishing! :big_smile:
     
  13. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Epoxy won't hurt aluminum.
    You need a 2-1 mix ratio epoxy.

    I use Marine Epoxy. I like it alot better then the expensive epoxies like System 3.
    Marine Epoxy is about as cheap cost wise as you can get into epoxy.

    Dont forget the plungers. They'll do your measuring for you.
    2 pumps resin, 1 pump hardener.

    If its a clamp on motor you'll need to add a sacrificial block of oak (preferably white oak) to your new transom.
    Otherwise your clamps dig into the transom wood which will breach the epoxy allowing a source for water intrusion.

    All you need is a piece of 3/4" oak. Just something that will take the beating but can be easily replaced.
     
    Last edited: Nov 15, 2009