Transom "ReBuild" from the Outside-In 17' Makee (Rajay 6011)

Discussion in 'Materials' started by bob andrews, Jan 20, 2018.

  1. bob andrews
    Joined: Dec 2017
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    Location: Jacksonville, Fl.

    bob andrews Junior Member

    Recently purchased a 30 yr old 17'Makee "offshore" with modest transom issues. Mostly in the engine drop area, water intrusion from the top and wicking down. My plan for the boat is to have a "Near shore" capability, as in trolling the beach & near shore, and having good trailing sea characteristics. That "IS" as good as a 17' can produce.
    I live in Jacksonville FL. and the inlet is relatively mild, at least on the days I plan to "Enjoy" fishing.
    The transom is currently cut for a 20" shaft, and I'm mounting a 25". The finished project will be a
    full transom being app. 28" tall, and the motor mounted on a 14"x 70" full width aluminum extension.
    Progress to date: Back transom skin removed & margined out, 3 1/2 @ sides & level across bottom.
    Rotten wood hulled out. ( Worked Well, using a technique from years carpentry) I say that because,
    for all the hours of research I spent understanding how others approached the task, I came up with
    ONE underlying result, that is, if it's not thoroughly rotten & de-laminating the entire process is laborious and time consuming. More on that down the road.

    My build plan goes something like this:
    1: fabricate a over sized panel 1/4" thick to replace removed.
    2: fit new panel & "adequately" bond & brace for the poring of the "Arjay" transom putty.
    3: lay up a New larger transom cap, app 4". original transom is 1 1/2" end to end, I'm looking for 5 -6"
    and consistent from rail to rail
    4: fab. up of aluminum motor/swim platform.
    5: Go Fishing!
     
    Last edited: Jan 24, 2018
  2. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    A few pics would be great.

    It's a little late now, but the reason most do the repair from inside is beacuse if the transom is bad, typically the stringers and floor are too, so you end up gutting the entire boat.

    If you know only the transom is bad then doing it from the outside is easier sometimes.

    I didn't quite understand the transom cutout description, mainly what you left at the lower portion.
     
  3. bob andrews
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    Location: Jacksonville, Fl.

    bob andrews Junior Member

    Pics "R" coming, just have to figure out HOW??
     
  4. Boat Design Net Moderator
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    Boat Design Net Moderator Moderator

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  5. bob andrews
    Joined: Dec 2017
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    Location: Jacksonville, Fl.

    bob andrews Junior Member

  6. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    From the pic in the gallery I could see you left enough at the lower part to get a bond. Just from looking at the transom from the outside it looks like it may have been easy to do from the inside.
     
  7. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Judging by the images, you've had some fun, but the transitions from old to new work need to be addressed. All of the old transom needs to come out and I know this sucks, as I've done lots of transoms, but to get a good bond, the new material needs to be "tabbed" to the old hull shell. You can't successfully bond to the old transom core and still trust the old tabbing to core bond, will still work in the new transom. For this reason the core has to come out, the remaining skin (inner, hull shell and outer skin) need considerable "toothing" (I use 24 to 40 grit), before any reliable new core can be tabbed and bonded back in. Now, if the old tabbing is still well bonded (usually is), you can bond to it, but (again) the old core has to be removed from it, to insure a good bond.

    Some will suggest you can scarf the old core remnants to the new core. I'll tell you, the inner skin will first show a crack, around the perimeter, followed by a similar crack on the out skin and inbetween, the core (plywood) will have "hinged" and forced the two skins apart,regardless of what others have said wouldn't happen. I've done dozens of transom core replacements and there's some good information out there, but a lot of crap by folks that haven't had to redo their own or someone else stuff again. You eventually learn and develop procedures that work, or your eat a lot of prior stuff.

    As you've learned, the still solid or mostly so core material, is a pain to get out. I've found a hand power planer the best tools to rough it in, knowing full well the staples and stuff are going to nick the blades. A multi tool is next, for getting down inside the flange areas and lastly, just plain old beat the crap out of it with a chisel and some creative cursing. Once most of it is hacked away, an angle grinder with a very rough grit, will remove the remaining wood and you can switch to a diamond blade (like used on tile) for cutting the 'glass portions.

    With the transom opened, cleaned and toothed up, you're ready to insert a new core. For strength, stiffness and particularly if using "exterior" grades of big box store plywood (not pressure treated) you're much better off using multiple layers of thinner stock then a few thicker. For example a 1.5" thick transom, can be done with 2 layers of 3/4", but the big box store material has a low veneer count, lots of internal defects and other concerns, so a better way is 3 layers of 1/2" plywood instead, better yet 4 layers of 3/8". Additionally, if the grain orientation of the plywood pieces are canted about 22 degrees, between each layer, in each direction, you'll gain a significant strength and stiffness improvement, just by this plywood orientation.

    Lastly, taper the transition areas of the old exterior skin. Typically this is 12:1 ratio, but more is better. This means if the skin is 1/4" thick, the tapered area on either side of the seam line is 3" to make a 12:1 transition. This permits the old 'glass to have sufficient material removed, so the new 'glass has a place to live, still being relatively flush, but most importantly enough contact area, to prevent the old to new work from busting out under load, which a bracket is going to increase over the previous arrangement.

    One last tip, steal your other half's can of hairspray. Yeah, you'll smell funny, but it works. Spray all the usual locations that itch from 'glass grinding, such as the elbow joints, around the neck and waist, etc. It'll wash off, but the micro fibers can't (mostly) get into your pores to cause itching.
     
  8. bob andrews
    Joined: Dec 2017
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    Location: Jacksonville, Fl.

    bob andrews Junior Member

    Up date, Thank You ALL for the encouragement & advice.
    The serration method used to help with "Bulk" core materials removal worked Great, well worth the prep. time. Secondly, to be done with the perimeter. Short of the very center of the hull area the "wood" core material was Dry and on perimeters. I used a 3 fluted auger, cutting to near full depth (like - 1/2"of inner glass) shoulder to shoulder, followed with same size flat spade cutter with the centering point removed. This allowed for final wood removal right up to the inner glass, allowing for "Near" ease of the removal of remaining cor material. Now fully sanded and ready for rebuild.

    Question, Please! I had planed on creating a New panel for the back prior to poring the new "composite" core. But are now leaning toward clamping "Melamine" to the back, Poring flush to existing, and then grinding back & glassing over.
    I have a Good 3" to work width allowing for the 12 : 1 ratio and will be easier. What say YOU?? PAR, I'm specifically interested in your opinion.

    Some new pics. (I hope)
    P1050126.JPG P1050130.JPG P1050127.JPG P1050134.JPG P1050133.JPG P1050137.JPG
     
  9. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Your pictures don't show the tapered flanges (12:1 thingee) around the perimeter, so you still have some grinding to do. What type of core are your "pouring"?
     
  10. bob andrews
    Joined: Dec 2017
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    Location: Jacksonville, Fl.

    bob andrews Junior Member

    Correct, Holding at this point , weighting 2 options.

    1: lay up a "new" 1/4" skin (with biaxial) fit & brace it as it sits, pour, then grind back margins and fair to finish.
    2: Wax up melamine cover, pour, and then grind back & lay same 1/4 skin.

    I'm leaning towards #2, allowing for a thicker core & easier one step lay up, even though it will be on the vertical.
    I'll be using Aajay 6011 http://www.arjaytech.com/images/ProductSpotlight_CeramicPourablev3.pdf

    This will be a (Full Transom) with outboard bracket, swim type platform across in aluminum.
    & Thank You for the reply!!
     
  11. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    This is a polyester, pour in product, which has good and bad things to consider. The good is it's seems relatively easy, given good prep, but this is the butt kicker on these types of products, the bond surface needs to be exceptionally clean and well "toothed" for a good polyester to polyester bond. Chasing down and removing voids is a common problem and containing the pour when a large portion of the transom or pour area needs to be made/temporarily supported/bonded back in, etc.

    With you transom, you'll have to support the exterior skin (if you reuse it), so it's square and plumb to the origional position. This means it'll need to be (well) braced in position and the seams at the least bonded or taped so you don't have a leak. I've seen this go easy and I've also see huge messes, once they've realized the skin has sprung a leak and goo is oozing out on the ground. Consider how you'll support the skin, as it'll be under a great deal of pressure, particularly along the lower edges.

    I'm not sure how your bracket is arranged, but with some thought, you could incorporate the pour with modifications to the stern, to include mounting bosses, maybe a ridge to offer the swim platform a uniform or custom landing point, maybe a door, possibly a boarding ladder, etc. Of course it means a more complex mold, but the end result could be rather beneficial.
     

  12. bob andrews
    Joined: Dec 2017
    Posts: 6
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    Location: Jacksonville, Fl.

    bob andrews Junior Member

    Waiting on a few Yards & Gallons, and the temperature to hold 70*/75*for a day.
     

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