Transom Repair for '73 Ranger

Discussion in 'Boat Design' started by mkimler, Aug 16, 2007.

  1. mkimler
    Joined: Aug 2007
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    Location: Texas

    mkimler New Member

    I have aquired this 1973 ranger bass boat from my dad after discovering it has a rotted transom. After removing part of the cap to expose the transom, i found that the majority of the wood was nothing but dried chips that I could basically remove with my hands. Once getting 3/4 of the way to the bottom, the wood became much more solid and even wet.

    I am now trying to work on the upper edges that you see in the picture where I didnt bother cutting into the cap. The angle of approach is quite difficult. If you look at the top of the picture, the cap actually angles upwards. Some wood still remains up inside. Im not sure as to how much I have removed nor if I can even access all of it without cutting that part of the cap off. I need some advice on how to tackle this. I also feel that this area is going to prove difficult when pouring the new transom. I plan on using the Seacast product. If I pour the Seacast into the exposed area, it wont be a high enough level to actually fill in that angled piece of the cap. There basically will be a void in the transom. I dont have any experience with repairing transoms, but I am aware that the bulk of the force from the engine is delivered into the side of the boat and thus it will be missing some load distribution. Any ideas?

    Attached Files:

  2. mkimler
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    mkimler New Member

    I think the big question I am asking here is how important are the upper two corners for support of the transom? Does anyone see any problem in just pooring the new transom in and not filling in the upper to voids? there is no way of accessing that area without removing more of the cap or removing the entire cap on the boat which would be more work that its worth. This is a 30+ year old boat. Appreciate any help.
  3. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    I'm not sure what you are talking about, but normally the transom ply you dug out would only be in the white hull part and not in the yellow cap part. If there is wood in the yellow cap it is not too important for transom strength, but just serves to reinforce the cap, which, with all the small boxy shapes in that area, is pretty strong by itself . In a boat like yours a large portion of the engine force is transfered to the hull through the splashwell in front of the transom. Of course it all depends on how much HP you plan to put on it. There are limits to everything.

    I'm not sure, but I wonder if there might be more to worry about strength by leaving the wet solid ply at the bottom of the transom and pouring the Seacast over it. Again, it depends on HP. But, you are going to trap that in there and when it rots, you won't be able to reach it easily.
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  5. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Sea Cast is a core material. It functions by curing to a dense material and bonding strongly to the inner and exterior 'glass skins. Both of these attributes need to be maintained or core sheer can result, making your transom useless.

    In short, the transom cavity needs to be free of dirt, moisture, debris, rotten wood, etc., or you'll be affecting the bond. The bond is critical for success, as it is in all cored structures.

    The deck cap appears to have some structural value, judging from the laminate. It would be wise to have the transom occupy this area as well (as was originally). I generally, I cut the cap off and fill this area too. Yep, it means sealing up the gaps and some holes in the top of the cap to pour in the transom in a can goo. The resulting holes can be patched with convention 'glassing techniques.

  6. charmc
    Joined: Jan 2007
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    charmc Senior Member

    Sam and Par have identified the crucial points. All rotted wood needs to be removed, or the problem will grow unseen. The Seacast website buttons labeled "repair techniques" and "Capping" illustrate Par's point well. You csn either drill holes through the cap to finish the pour to full height, or cut off the cap and glass over a new cap.
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