Cracked Keel 1999 starcraft 2290

Discussion in 'Boatbuilding' started by Ra3ei Ba7er, Sep 22, 2011.

  1. tunnels

    tunnels Previous Member

    You have a major rebuild on your hands but need to see pictures when evrything is out of the inside and can see the damaged area More pictures please Inside and out side !!:eek:
     
  2. Ra3ei Ba7er
    Joined: Sep 2011
    Posts: 58
    Likes: 3, Points: 0, Legacy Rep: 26
    Location: Saudi Arabia

    Ra3ei Ba7er Junior Member

    Hi again
    Today we removed most of the foam top of the crack
    kindly advice what I should do next
     

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  3. tunnels

    tunnels Previous Member

    Looks like some one has done a repair before at some time . This is a common problem because the Strake along each side of the hull the glass has first delaminated because the hull botttom has been moving up and down !!
    The 3 corners of the strakes are a weak point so thats where it breaks every time . You will have a lot of grinding to do to get back to nice clean glass again .
    Some one has poured lots a resin there as well so has cracked and broken as well .
    All needs to be gound off to get back to bare clean glass at least 300 mm on the high side of the strake and down into the keel .
    When i get to work in the morning i will draw out on cardboard and photograph a discription for you what you have and what you need to do!! ok !!!
    Needs to be reglassed as far to the front as possible and as far to the back as possible also .
    Back in the morning !!:)
     
  4. Ra3ei Ba7er
    Joined: Sep 2011
    Posts: 58
    Likes: 3, Points: 0, Legacy Rep: 26
    Location: Saudi Arabia

    Ra3ei Ba7er Junior Member

    I very much value your input, I will follow your repair instructions, please also include the tools, material etc. specs
     
  5. tunnels

    tunnels Previous Member

    Ok am at work !
    What Glass materials do you have availible that you can get ??
    I will go now and sort what i have to draw . Back soon !:D
     
  6. tunnels

    tunnels Previous Member

    When all the totall surface has been sanded with a disc grinder and completely vac cleaned out time to start rebuilding . What i have in mind does a few things
    first the bottom is weak second the trailer beds are a part of the problem of what has happened , thirdly this is such a common problem when the manufactures dont use there heads and laminaterd dont think
    The 3 small red circles are the weak places on any strakes are the weakest places and always flex in those corners !!
    The glass hardly ever breaks just delaminates and the layers separate from each other . The pressure of the water at high speeds gradually works its way to the weakest place from the outside and then its in and forces its way from one end to the other so really its a total repair that has to be done !!what you see on the outside is just a small part of the actual problem that inside the boat . The first thing is to repair the strake with good glass to be able to build on top of . See the picture the glas needs to exstand well on each side of the strake then the whole side of the bottm of the hull so you get a double up of glass in the strake !!
    I suggest You put down a 450 chopped strand matt then a 800gram double bias or woven roving then another 450 csm over the top this need to exstend from 150mm over the keel,all the way up the bottom to the chine !! including the strake again !!!
    This run needs to go from as far back as is possible to get to as far forward as possible with no joins anywhere if possible !!.
    When one side has gone hard then you can cover it and stand on it and then do the other side . Overlap the keel again 150 mm from the other direction so in reality there should be 6 layers of glass ends up on the overlapped join in the bottom of the keel .
    You will be thinking this is overkill but the boat has had a hard life so lets fix it once and for always .
    With the strake Usually i try to use H 80 foam 18mm thick 70mm wide and cut from coner to corner ( see the picture ) and stick it in with resin ,talc and aerosil mix! then glass over the top with 1x csm, 1 x double bias and another csm . try to use continuous lengths of glass where ever possible but if you have to join it ok make sure all joins are no less the 50mm over top of each other . You will see i have formed a stringer from pvc foam !The shape is quite important with a nice radius on top and a slight angle on each side .Your floor can rest on top of the finished glassed stringer !!
    Needs to be about 120 mm wide at the base taper to 100 mm at the top The height you will have to work out for your floor levels . .
    The positioning needs to be where the strake is but you can shift a little up towards the chine or down towards the keel a little !!, look where your Trailer beds are and try to get the vertical sides of the stringer placed directly over the trailer bed .
    The foam is just a former and has no structual strength untill it is glassed . Once Glassed this is a major member to strengthen the hull side and take the weight of the whole boat sitting on the trailer . It is also going to become the stringer that was never there , so the glassing need to be strong but have just a little flexable as well . Laminate i suggest ! 1 x csm ,2 x double bias ,1x csm
    Look closely at the pictures and see all the layers have a overlap on the very top of the stringer so when it is finished it has 8 layers of differant glasses on the top . This forms a eye beam effect !!!
    Normally i would suggest put at least 3 or 4 layers of 400 gram unidirectional glass 100mm wide in amongst the top layers as well . This will form a very strong frame once your floors are reattached and glassed down again .
    With what i have written and the pictures i hope you are able to follow . Its really easy and is straight forward and simple !! Use vinylester resin if you can for everything . In the strake add a extra layer of csm under the double bias if the hull is looking lumpy and bumpy and there are places where the old glass has been cut away ond ground off.completely !! With the new stringer and all the extra glassing there will never be any excessive flexing or bending to worry about ever again !.
    Whew now i can go do my own job !!
    Have a nice day Bye !!;)
     

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  7. Ra3ei Ba7er
    Joined: Sep 2011
    Posts: 58
    Likes: 3, Points: 0, Legacy Rep: 26
    Location: Saudi Arabia

    Ra3ei Ba7er Junior Member

    Thank you very much for the details
    Yesterday night and before reading your reply my supervisor suggested Extensive grinding all over , Taper grinding along the crack. Then 6 layer ( or more ) repair plan as in the picture below, the first 4 layers each one wider than the other by 5 cm, all on top of the crack, then continuous 2 layers with no joints all the way from one side of the boat the other.
    what do you think?
     

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  8. tunnels

    tunnels Previous Member

    The glassing is better to be done each side seperatly so you get the build up of joins in the middle this will in effect form a keel of extra glass .
    The stringer done the way i have shown in my drawing will serve you better than multi layers of glass all piled in one place !
    Yes the glass could go right to the chine but not up the hull side as it could start to draw and make the hull side bend a little .
    If you dont have a stringer the bottom of the hull it will end up still flexing and bending up and down .You will be able to mount the floor back ontop and screw into the top of the stringers !!, Believe me i thought this over all night . The beds where the boat sits on the trailer need to be looked at as well as they are possible a big part of the whole problem . :)
     
  9. Ra3ei Ba7er
    Joined: Sep 2011
    Posts: 58
    Likes: 3, Points: 0, Legacy Rep: 26
    Location: Saudi Arabia

    Ra3ei Ba7er Junior Member

    I forgot to say that after his 6 layers plan, he will make new foam of same size as before and glass it with as many layers as we can.
    From your drawings and pictures, is this U beam shaped straigner have same size as I can see it ( 5-6 cm)? what about the old foam, should I put new foam of same size as it was or what?
     
  10. Ra3ei Ba7er
    Joined: Sep 2011
    Posts: 58
    Likes: 3, Points: 0, Legacy Rep: 26
    Location: Saudi Arabia

    Ra3ei Ba7er Junior Member

    Today and yesterday we did grinding all over then lifted the cracked part up to its place, the applied a mix of resin with talc powder as filler in the cracked strike area, laminated with CSM 455 and the woven roving 600, then fixed straigner made from strong foam used in boat industry ( I forgot its name) I could not find foam similar to yours, tomorrow we will laminate it as you said, then I will 2 inch plywood, laminate it and then fill it with liquid foam, I will keep on posting work progress with pictures until we finish, your opinion will be valued
    Pictures are below
     

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  11. tunnels

    tunnels Previous Member

    fill it with liquid foamDont put any liquid foam in untill you are almost completely finished . Is best not to use anyway because it gets wet and soaks up water and will make the boat heavy !!:eek:
     
  12. Ra3ei Ba7er
    Joined: Sep 2011
    Posts: 58
    Likes: 3, Points: 0, Legacy Rep: 26
    Location: Saudi Arabia

    Ra3ei Ba7er Junior Member

    the old foam did not soack no water at all, do you prefer not to use no foam?
     
  13. tunnels

    tunnels Previous Member

    Ok is your choice if you use again is not in the lowest part anyway so maybe ok to use !!
    Did you fill the strake after it was glassed with 2 layers of glass ?? Needs good glass and filled with h80 density so is strong and then make flat with hull on top and glassed over again . Then glass whole one side keel to chine !!. You have vinylester resin ? :D
     
  14. Ra3ei Ba7er
    Joined: Sep 2011
    Posts: 58
    Likes: 3, Points: 0, Legacy Rep: 26
    Location: Saudi Arabia

    Ra3ei Ba7er Junior Member

    Good morning, Yesterday no work was done, we will continue today.
    As I told you, grinding then pushed the cracked part of strake up to original place, applied mix of resin with talc powder to close any gap, glassed strake with 3 layers, the remainig strake gape wad too small to be filled with anything like foam, I applied resin+talc, placed the new staigner and will glass it today.
    The resin I found and used is called ISO resin it is used by marine shops.
    As I told you I was surprised that the old foam was very solid and no water was in it or even signs of water, which proofs that the boat was ok or at least did not have had a major leak before but somehow somewhere in the journey from Florida to Saudi Arabia It got damaged.
    With your expertise instructions I am confident that it will be repaired to a much better condition than original new one.
    More pictures of today work will be posted in the evening, hopefully.
     

  15. Ra3ei Ba7er
    Joined: Sep 2011
    Posts: 58
    Likes: 3, Points: 0, Legacy Rep: 26
    Location: Saudi Arabia

    Ra3ei Ba7er Junior Member

    Today we started too late, we laminated one straigner, by the way the straigner is made from divinycell
    see the pictures
     

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