Transom Rot

Discussion in 'Boats and Motors' started by Bluegrass Boy, Mar 22, 2008.

  1. I have a 1986 fiberglass bowrider 19.5' that has a soft floor. I am replacing the floor next week. Since the floor has rotted, I want to check the transom to make sure its o.k.

    What is the best method to check for transom rot?

    If there is minor damage, is there an easy repair, or do I have to have the transom repaired?

    Any help would be greatly appreciated.
  2. what's the make on the boat? Reason I ask is because some will use foam filled glass laminate for the hull, and some will use plywood or balsa laminated w/glass.

    easiest way to check for rot is to take a hammer, or large wrench (anything steel) and thump the areas that you suspect are rotting. you'll hear a difference where rot is, like a deep thud versus a solid smack. It's difficult to really explain the difference in sound in words, but you'll know it when you hear it.

    other option is to take a hole saw and cut out a sample of the core. that way you can see exactly what you've got in there, but also, if there's not a problem, you've got a 1" hole to patch...

    and just a suggestion, I don't know what your floor consists of, but most times its glass/ply or balsa/glass sort of sandwich. by far the best way to do this, if you're doing it yourself, is to take a 4" grinder w/ a cutting wheel on it and just cut through the top layer of glass, usually no more than a 1/4" thick. take a chisel and hammer and peel off the glass ontop, then chisel away the rotted wood inside. same goes for foam. then you can clean up the bottom layer of glass with a grinder and you have something to lay the new core up against, versus fighting with gravity later on.

    If the whole floor is shot and you're replacing the entire thing, you can cut it all out, and take the time to laminate your dry fit replacement plywood w/glass outside of the boat.

    If you have any more questions, feel free to send me a PM or an email. I'm finishing up college and do alot of this sort of work to pay the bills in the meantime. Have a shop out in Vermilion.


  3. UFM82

    UFM82 The one others want to be

    A drill bit large enough to capture some shavings is sufficient. Drill a hole in various out-of-the-way spots,(under the engine, etc.) and check the shavings. If the wood is black and damp, you have water in the transom. If it is soft and spongy you have worse probelms. If it is dry and hard like regular lumber shavings, you're good to go. By making the holes small enough, you can simply take a tube of 5200 and force it back into the hole and let it set. If you have a white hull it will barely even be noticeable. If it is a colored hull, you can try to match colors with a mix-patch or simply touch-up paint the 5200 once it's dry.

    If the transom is rotten, it may be more than the boat is worth to fix. A quality transom replacement could run $2,000 although you're doing the floor at the same time may make things easier. IMHO, the boat isn't worth it if it needs everything inside replaced. If the floor is bad, chances are stringers are bad and on and on and on. Money pits are easy to come by unfortunately.

  4. The boat is a Sunbird. The transom is plywood/fiberglass. I got the boat last August and I banged around on the outside of the transom (outside the boat) and it seemed solid. It is definately solid around the outdrive and there is very little movement when I pull up and down on the inboard (I'm 6'1" and 270 pounds so I put a lot of pressure on it).

    If I find a small area of rot can that be patched or does the whole transom need to be replaced?
  5. Check INSIDE the bilge area, below the waterline on each side of the outdrive. My brother had a '92 Thompson where the transom rotted inside the bilge area. I could stick my finger through the glass and the first layer of plywood. The outside appeared to be solid.

    We were out of Edgewater 3 miles north of the crib and we started to take on water. We opened the doghouse and I saw the water coming through a pinhole at one of the corner joints. I thought my bro was going to need a new change of underwear!