Seaswirl Tempo 17 sole, mounts, stringers?

Discussion in 'Fiberglass and Composite Boat Building' started by ster1, Apr 30, 2013.

  1. ster1
    Joined: Aug 2012
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    Location: colorado

    ster1 Junior Member

    Hello Folks,

    It's me again, with more rotten wood. I am looking for some help. I started off just wanting to reupholster my crappy back to back seats and this is turning into a big ol CF. My craft is a 1985 Seaswirl Tempo 17 with a 3.0 OMC 400 stringer mechanical shift outdrive. I rebuilt the drive and actually like it (believe it or not) and the engine has unknown hours but consistent compressions, good oil pressure, and gets me on plane in 6 seconds every time (unless I'm pulling a skiier or something). So no complaints about the engine or drive. What happened is probably familiar to most of us; I started out with something minor in mind and it's turning into something major. I have a few youtube vids I posted on my channel I will try to post them here so you can see what I'm up against.

    https://www.youtube.com/watch?v=o-rFxg6BquU

    This is the first vid I took that shows some of the floor removed and the problem I'm really asking about. My problem is my engine seems to be mounted to blocks that have been laminated to a piece of plywood that runs right next to the stringers and then laminated to the stingers with fiberglass. Other than the fiberglass itself there is no other physical attachment to the stringers. Here's another video that might clarify a little:

    https://www.youtube.com/watch?v=Y1qC4OtCNBs

    So the plywood next to the stringers was completely rotten, and probably has been for quite some time. I was pulling skiiers last year rolling that thing from idle to WOT all day, with no trouble. My first question would be, is my assumption correct that the only thing holding my engine in there was some fiberglass wrapped around a block, and no real connection to the stringers other than that fiberglass? Why didn't that engine come flying out of there? My boat building ignorance is shining through here. So now I've got a piece of rotten plywood that may or may not even be needed, and also the blocks the engine is mounted to are rotten so some degree. I think I'm looking at pulling the engine, and of course there is a long list of "while you have it out" stuff about the engine, but is it safe to assume this can be repaired? I plan on using the same method as the floor, cut out the old, install the new, fiberglass and all. I'm a little nervous messing around with the engine mounts just because the forces while underway are translated directly through my "repair". I haven't even decided if it's worth it at this point, also. That's a conversation for another day though. The big question is, can it be done by someone like me who obviously doesn't know enough about how boats are built? I know engines, I'm good with fiberglass and I'm OK with woodworking. It's combination of the 3 that are potentially disastrous. Sorry for the long post. I welcome your thoughts. Cheers!
     
  2. tunnels

    tunnels Previous Member

    Where are all our experts ??
    Resin and glass over wood specially, polyester resin and chopped strand is really a no no but its quick and cheap when done in a factory and you are seeing what age does !!
    If you taking the motor out then once its gone and completely cleaned up post some more pictures and then we can see what really needs to be done !!
    All and any ply you will be useing needs to be cut to shape and size and edges ground and sanded and what ever so its fits really good but with a small gap round the edges then take it out and resin coat all sides specially edges and the underside !! Usually this is never glassed and dosent even get resin coated either !! Edges where there end grain really is the place where water gets in and travels a long way so a second and third coat of resin on those so its 100% sealled before it gets placed back in the boat and eventually glassed over again .
    There is no reason for not reusing polyester resin again ! JUST make sure all surfaces where new glass will be going onto Old glass is sanded and 110% cleaned to get a good bond !! epoxy is better but its also really exspensive and once you start usng it you have to carry on till you finished !! Polyester resin will not adhere to Epoxy so you should not try to mix and match the two !!
    Pre cut glass tapes are availible if you shop around double bias with a csm on one side is a really good choice for tabing and doing edges etc ! bonding onto a old glass surface you need to use a minimum of 80 mm wide all round all edges ,More is better !:D
     
  3. ster1
    Joined: Aug 2012
    Posts: 61
    Likes: 1, Points: 0, Legacy Rep: 16
    Location: colorado

    ster1 Junior Member

    I think you missed the point. I wasn't curious about epoxy vs polyester or methods of sole replacement. My questions had to do with the engine mounts and stringers and related construction. I guess what my question really boils down to is where does the strength come from, the fiberglass or the wood, or both? Here is a vid taken today:

    http://youtu.be/BHjPDkGLPQY

    I drilled my stringers and transom, and found rot in the transom and the stringers are hollow! I'm confused and don't know how or why that would be. I didn't want to get into the transom and am thinking this boat is going away, sadly. I really don't know how to tackle this.
     
  4. tunnels

    tunnels Previous Member

    Mine was a general answer .
    Engine mounts !
    Initally any wood used takes the loads but as it degrades and becomes soggy and wet and eventually rots and become usless the glass takes all of the strength !! So the glass needs to be strong right from DAY ONE !!
    So tell what you intend to do !! cut out the old and replace ??:confused:
     
  5. tunnels

    tunnels Previous Member

    We are here to help with what ever you decide to do !!

    Dont you just love glassed over wood inside boats !! after seeing your video yes i am not surprised at what you found with the transom as well .
    Its is possible to dig out and replace everything but the choice is yours !!
    Taking apart is disheartening but is not the end of the world . we have guided people through totall rebuilds which included deck removal as well so you just sit and have a think what you want to do and we will await your decission !! Stern drives are netorious for getting wet because people never seal the big hole or the bolt holds properly so first time in the water is when it gets wet and everytime there after !!!
    Choice is yours!!
    :D:p

    Stringer , engine mounts and transom! You can replace all and make a better job than what it ever was even from new just up to you what you want to do and how far you want to go !! Planning carefully and modifying and using better materials will give you a boat that could last you the rest of your life !!
     
  6. missinginaction
    Joined: Aug 2007
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    Location: New York

    missinginaction Senior Member

    I haven't time to get into this tonight but wanted to let you know that I did watch your video. It looks to me as though that plywood you're concerned about was simply used as a spacer of some kind. You say the blocks are not bolted or attached to the stringer. Are they attached to the bottom of the boat, the inside of the hull underneath the block or did it look like they were glassed to that now rotted ply spacer?

    It's hard to tell from the video but your boat seems to look OK from the outside so it might be worth doing. Those seats.....forget about them. Just get a couple of new ones if and when the time comes. It won't cost much if any more than trying to get those redone.

    Lets wait and see who else might get in on this. Everybody around here is getting pretty busy so be patient and check back.

    MIA
     
  7. tunnels

    tunnels Previous Member

    The blocks the motor is sitting on really have been an after thought !! That is not a good way of mounting a motor reguardless what size it is !!
    The mounts should be attached to and part of the stringers so the loading in any direction is taken over a much much bigger area!!
    Plus build into and substantually glass over a couple of steel plates at least up to 12 mm thick so it can be drilled and a threaded into it to hold the motor mounts !!.
    In the event of a hypothetical roll over the motor then has very little chance of falling out or coming loose and ripping the stern drive loose off its mounts on the transom and causing the boat to sink !!!tail first !!
    You will get asked to use WOVEN ROVING for sure but in reality the same weight of double bias glass is a far better choice .
    Same if you do the transom think about what has to be done and use good materials !!. With glass its the oriantation of the glass strands to distribute stress and loads thats very very important !!:D
     
  8. ster1
    Joined: Aug 2012
    Posts: 61
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    Location: colorado

    ster1 Junior Member

    Yes that plywood did look like some sort of spacer. I believe it was actually used to give something to mount the blocks to before being installed and laminated to the stringers. It turns out this type of engine mount is not uncommon even on bigger boats. It was 'glassed heavily to the stringer and the bottom until I got there and started hacking it apart. I took off the out drive last night and I'm going to try to pull the engine today to get a better look at the mounts and transom. A this point I have nothing to lose.
     
  9. tunnels

    tunnels Previous Member

    Yes at this stage is best to ite the bullet and get enthusiastic and do the lot all in one swoop . try other parts iof the transom as well out to the sides and higher up . The water would have travelled over the whole thing top to bottom side to side repairs are best done from the inside if it at all possible The outside laminate id usually thinker then whats inside so holds its shape better when you reassemble and rebuild . The hull stringers try them all the way from stern to wards the bow it could be the same thing wet soggy and soft . Rebuilding is very satifying and a really good feeling to know that you will have a good boat again much stronger and better than before . Post a heap of pictures as they are easy to load and look at closely !!. Plus i cant get You tube in china !!! Im in new zealand now till tomorrow morning and thats my last shot at Youtube !! :D
     
  10. missinginaction
    Joined: Aug 2007
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    Location: New York

    missinginaction Senior Member

    Before you get too crazy pulling that engine, consider that you'll need to make up some kind of jig that you can put into the boat to show where your new engine beds will need to be located. You'll want the mounts to land where they are now so you'll need some way to locate them after everything has been removed from the boat.

    MIA
     
  11. ster1
    Joined: Aug 2012
    Posts: 61
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    Location: colorado

    ster1 Junior Member

    I pulled the engine and drive today. I took measurements where the engine was. I should have made a template though, that would have been easier :). Here's a video from today; it's kinda crappy because I had my music playing and the noise outside makes it hard to hear me, sorry about that. I'll take some pics and put em up in Picasa tomorrow.

    https://www.youtube.com/watch?v=67jv1E5xu0s

    Anyway, the stringers are hollow and will never rot, which is good. The transom is trash, BUT the wood doesn't go all the way around left to right and top to bottom. It just extends to past the stringers and not even all the way up. The transom is weird. I'm thinking there can never be a Merc in there because of the way the transom is built. If I can't put a Alpha 1 in there, I don't think I'm going to go through with it. There's nothing wrong with my OMC but I'm having a hard time justifying the work this will need if I can't get a new drive. Do you think I can install some gussets maybe on either side of either stringer, glass em in and create enough support for a Merc?
     
  12. tunnels

    tunnels Previous Member

    You are getting there !! well done !!

    One handed videos take a little to watch !! two hands are better and a little more light !!
    Ok so the side panels are solid and possibly 100% ok !! That not a bad thing
    !! Transom can be built in many differant ways . Just to clear up a point when you saying installing a merc you mean a merc stern drive ?? or a merc outboard ??
    Either way the centre piece is all you really have to worry about !! where theres a space between the sides to the centre is in reality that has saved you having to replace the lot !! i would say the sides were fitted and glassed in totally then the middle was fitted and glassed so the glass has stopped the water going side ways .
    This very pinciple of dividing the tramsom into 3 sections i still do to this very day !! but the sides i use high density foam core bagged into place on wet layers of glass and then completely glassed over and sealled up ,Then the 50 mm thick plywood centre is fitted in to place and it to is on layers of wet csm glass and vac bagged so the resin really penetrates Into all small wee gaps and holes there could be when the packer is made . Then it in turn is glassed over and that glass goes out over the foam side panels a good 250mm all round !! sides ,top ,and out onto the hull bottom !!so like you have there is only the centre that can get wet and possibly rot !
    The stern drive cut out we make a little over size and glass over that as well with really wet csm glass and then hand sand and gell coat so the stern drive slides into its hole and dosent foul on anything . Takes time is a little more work but really worth doing because in 15 years never had one transom ever get wet and they certonly never rotted !!.
    By the look in the video there is a shelf running along the transom??
    would be a good idea to remove it and allow better access to the back area when you have to grind and sand the old glass !!!! Keep at it thats the thing !!Never give up !!:p
     
  13. missinginaction
    Joined: Aug 2007
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    Location: New York

    missinginaction Senior Member

    Slow down a bit before you start messing with the transom. There are ways to build/rebuild transoms, of course. If the outer gel coat and glass are OK you can leave that alone and work inside the boat. Sounds like you want to make your transom stronger? People have taken a couple of sheets of 3/8 ply and laminated them to the outer skin one sheet at a time using epoxy. You drill small holes in the transom and draw the assembly together using screws and fender washers or some other mechanism to pull the work together. You can search here and find examples of what others have done. I do not know how much you need to add or how heavy your transom should be. You might be able to use 1/4 inch marine ply and build up to 1/2 inch thick. This would be pretty easy to work with as it's easily bendable in single sheets.
     
  14. tunnels

    tunnels Previous Member

    The thinest transom we make is 45 mm thick for stern drives in all and any production boats we make !! Over build never under build !!
    Use thick ply to build your transom not multi layers of thin ply !! 3 layers of 15 mm is the usual , Its a reall hassle to build thickness with thin ply !!. The later stern drives have the rear motor mounts as a part of the inner brackets so there is only the front Mounts to build preferably as part of the stringer system :D:p
     

  15. missinginaction
    Joined: Aug 2007
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    Location: New York

    missinginaction Senior Member

    Wow, 45mm is equivalent to a bit over 1 3/4 inches. That's pretty thick, and heavy. I believe that you will find that a much less substantial transom will serve the purpose. A Glastron that I ran for 30 years was made with 1/2" of ply sandwiched between about 3/32 or so of fiberglass cloth. Held up just fine with a 140 HP Mercruiser sterndrive. I'd do some research on this before starting your project.

    MIA
     
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