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44 MY transom core question

Discussion in 'Viking Yacht' started by Viking44MY, Jan 20, 2022.

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  1. Viking44MY

    Viking44MY New Member

    Joined:
    Jan 10, 2022
    Messages:
    22
    Location:
    Chesapeake Bay
    So while poking around in my new to me 1988 44 MY I discovered something very disturbing. When I pull out the drawer on the port side next to the bed in the aft cabin I can see evidence (weeping from screw holes, hollow sound when tapping) of about a one square foot area of rotted transom core centered on the area where the trim tab pump is screwed to the transom. The odd thing is that this area is below the water line. The two trim tab hoses also appear to be installed through the core when looking at the inside of the transom, but looking at the outside shown in this photo they clearly exit the hull well below the water line. And the chine step shown in the photo is not visible from the inside, no obvious step-in on the inside of the transom. From the inside the core appears to go right over this chine step without a change in profile. From the inside looks like the core terminates exactly at the level where the lower trim tab hose goes through the transom, but this is clearly well below the water line. I had to leave the boat before I has a chance to investigate thoroughly but when I got home I looked at this photo and something doesn't add up. I'm wondering if the area that appears rotted is not the core, but is a piece of wood glassed to the back of the transom to allow mounting of various things, so not structural. From the photo I would assume that the core terminates at the chine or somewhere above the chine. It would seem difficult and pointless to continue the core below the chine during manufacturing. If it goes below the chine then it also goes below the waterline, which I didn't think was supposed to the the case with these Vikings. Does anyone know if the core in the transom terminates above the waterline. If this is the case then I think I'm okay. Transom.jpg
  2. ranger58sb

    ranger58sb Senior member

    Joined:
    Aug 20, 2013
    Messages:
    818
    Location:
    Chesapeake Bay, USA
    You have the advantage of owning a boat built by a quality manufacturer who is still in business. Your best info may come directly from them.

    -Chris
  3. Greg Page

    Greg Page Active Member

    Joined:
    Mar 4, 2017
    Messages:
    387
    Location:
    Annapolis MD
    This is a picture from when re-cored transom on my (prior) 35 Viking. You can see where it transitions to solid hull across the bottom of the picture. Transom turned out to not be as bad as expected (sounding made large area look questionable, IR scans were inconclusive). Bad spots where from platform attachments when prior owner had repaired/re-attached. When new core (synthetic) went in all areas with through holes were cored with solid fiberglass blocks.

    -Greg

    35 Viking Transom Recore.jpg
  4. BigChief

    BigChief Member

    Joined:
    Sep 3, 2018
    Messages:
    81
    Location:
    CT
    New to you Viking? How long have you had it?
    Did you have it surveyed by a knowledgeable surveyor?
    It can be fixed not to difficult but time consuming.
  5. Greg Page

    Greg Page Active Member

    Joined:
    Mar 4, 2017
    Messages:
    387
    Location:
    Annapolis MD
    That is our prior boat. We had it 5 years, it is now at my neighbors dock. Current boat is a 43 Post.

    Yes it was surveyed and didn't show up until several years after purchase. I first noticed a small black streak from water on the inside of the transom when crawling around under the cockpit floor for spring checks and maintenance. Had it inspected and since it is structural didn't want to wait to repair. Could't really be sure how extensive till it was opend up. Once open made no sense to go part way so replaced all the original core.
  6. BigChief

    BigChief Member

    Joined:
    Sep 3, 2018
    Messages:
    81
    Location:
    CT
    FYI
    My previous 85 41 Viking did not have any coring in the transom below the water line. The swim platform brackets and underwater lights when installed were drilled through solid glass about 1/2 thick.
  7. MBevins

    MBevins Senior Member

    Joined:
    May 23, 2008
    Messages:
    1,162
    Location:
    Windsor On. Canada
    Do you have a cap port side just above the swim platform? Used as a storage location for a spare shaft. If so, remove the cap and see if the core is exposed (or still there) .
    When I bought my 44 many years ago the transom had rot through that area, turned out they (meaning I don't know who) didn't seal the raw edge when the hole was cut. They relied on the sealant holding the cap .
    So if you have that cap, good news, you probably have a spare shaft. Bad news, it's probably leaking.
  8. Viking44MY

    Viking44MY New Member

    Joined:
    Jan 10, 2022
    Messages:
    22
    Location:
    Chesapeake Bay
    Thanks for the core photo. I believe the water entered my core through the penetration for the upper trim tab hose, but not quite sure yet. Still investigating. Could have possible come from the rub rail, but the glass rings like a bell above the trim tab hoses and all the way up to the rail, dull thump below the upper trim tab hose. The lower trim tab hose appears to be below the core. It’s a mystery why Viking would have installed the upper hoses through the core when they easily could have moved them down a few inches to be in the solid hull. I’ll also take a closer look at my spare shaft cap. The cap is on the side with the wet core. It appear the have good core when I looked, but I’ll check again and seal the core under the cap.