1970 Rondar 505 cracked hull (today)

Discussion in 'Sailboats' started by 500Lonepine, Jul 18, 2014.

  1. 500Lonepine
    Joined: Sep 2013
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    500Lonepine Junior Member

    Hello,

    Advice on the proper way of dealing with this problem would be greatly appreciated.

    Today, while rigging a 1970 505 on a gravel shoal, somehow I scraped, tore, poked about a 4 inch hole directly on the centerline of the bow. Upon completion of our two hour sail I noticed water sheeting out of this hole.

    The hole is not a clean. See the image below. I really want to go sailing again soon. What would the proper way of dealing with this be?

    Would it be possible to use West Systems fiberglass repair kit; Glass cloth, epoxy and and silica to make an external repair, but later have someone fix from the interior, sand and make the problem less visible?

    Any thoughts on how to deal with this would be greatly appreciated. Keep in mind that the 505 is an ex Olympic class racer therefore the hull is extremely thin.

    [​IMG]
     
  2. sailrob
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    sailrob Junior Member

    The west system fiberglass boat kit would be the right thing to get. Comes with instructions on how to do the repair. Just remember that if you fix with epoxy you normally can't apply a gelcoat finish. It won't adhere well to the epoxy. Painting would be your only option. Repairing the outside only might not be strong enough to withstand cracking of the repair. It would depend on how much you need to grind or sand away before applying the fiberglass cloth on the repair. In general the more you remove the more layers of cloth needed to rebuild thickness, the stronger the repair. Not easy to tell just by looking at the picture. If I were you I would consider doing inside and outside at the same time. Not that much more work. Never seen the instructions in such a kit. Could be a couple more helpful tips in books like "sailboat hull and deck repair".
    Good luck!
     
  3. 500Lonepine
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    500Lonepine Junior Member

    Hi Sailrob,

    Thanks for the help.

    So, are you saying that if I repair with the West Syatems fiberglass Repair kit (is it epoxy?) that I would then not be able to re clearcoat the boat?
     
  4. SukiSolo
    Joined: Dec 2012
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    SukiSolo Senior Member

    Thanks 500Lonepine, for posting the image and outlining the problem. Pretty straight forward to repair, so do not panic.

    1. Cut out the broken and cracked bit until you have a clean hole. Put your fingers inside and check no further cracking or loose fibres.

    2. I'd guess at this age, the hull is a polyester layup so you can use either polyester or epoxy to repair this. You can put gelcoat over epoxy, no real problem - see later. So choose your resin system, personally I don't mind either in this scenario - polyester will be quicker, but epoxy has the benefit of better gap filling and cohesive strength. The latter is better when dealing with lifting tank sides in the cockpit area for instance.

    3. Get some 200 gsm woven roving or if pushed equivalent Chopped Strand mat (CSM). Good resin and f/glass suppliers usually sell by the meter off a roll. One meter should be plenty (1 meter width).

    4. Get some stiffish polythene sheet, like a throwaway food container lid and cut it to match the shape of the hole but oversize it all round by about 10-12mm. Drill a very small hole in it and put a thin string like garden polyprop twine through it. Place this into the hole and pull on the string. I should pretty much take on the hull form from the inside.

    5. Make some arrangement ie a few timber battens or anything that can hold this tensioned string for some hours. For now remove the plastic piece.

    6. Chamfer the edges of the hole with an aluminium file or coarse (80 grit) sand paper. Ensure the inside face is also clean and sanded for 15-20mm from the sdge.

    7. Cut as many layers as needed for the thickness of the repair to the shape allowing a bit for gelcoat.

    8. Personally I try and get one layer inside at this point. So I would wet the inside face then put the plastic piece with string inside the hole. Push the end of the string through one layer of roving and feed it on. Wet out the roving whilst on the plastic, then carefully feed into the hole and pull into place. You should have one layer laminated onto the inside face and sitting tight down.

    9. You can at this point either clamp/tie it in place and let it set or feed another layer onto the string and wet out from the outside whilst keeping tension on the string. I'd probably make this initial 'sandwich' and clamp/tie off at this point.Do not over tension the string and create a bump.

    10. Let it set. After that you can grind back from the outside after cutting the string. What about the plastic piece? Well it is a dumb former and will not stick to anything. If you get really crafty you can usually feed it with a secondary removal string through a buoyancy hatch from inside the boat. Then you can retrieve the scrap piece. That is what I endeavour to do as it is neat and no rattles!.

    11. Build up the outer layers until 0.5 -1.0mm below surface. Sand these down until a nice fair shape.

    12. My preference here is to seal with a thin coat ofresin to ensure the fibres ater saturated and no water can migrate into them.

    13. Apply colour matched gelcoat - there are 'a lot of whites' but add 2% styrene monomer aka wax as this allows it to go off in air like paint. Ty and screed the gelcoat as smoothly and level as possible.

    14. Cut back the gelcoat. Lumps may be removed with coarse file but then you need a small block and to work through the grits say from 400 through to 600, 800 and 1200 grit. Remember to work the diagonals to stay fair to the hull shape and not go through the gelcoat.

    15. Polish it with a decent compound say a Farecla one or even T Cut.

    You have a repair! and can go sailing. Although it might seem a bit long winded it is pretty straight forward and does not take too long. You could do this in a day in polyester because it sets so fast. Allow maybe 2-3 days with epoxy because of setting times and also ensure all amine bloom is removed.
    One useful tip would be make sure you get a litre of Acetone for clean up.

    There are a few other ways to create the inner former, but generally I think I have covered the basics for a repair on this type of craft. You should try them with fancy cores, Nomex etc....;)
    If it does in fact have a core layer, I would use epoxy, as some core materials dissolve with styrene.
     
  5. AndySGray
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    AndySGray Senior Member

    Take the paint off the area

    The pic is not great - but it looks more like paint than gelcoat.

    If not the general rule for fibreglass repair is repair the damage not just the hole.

    What I mean is that the visible hole is like the tip of an iceberg and damage/weakness probably goes 10 times further.

    I'm also a little concerned with the colour - very dark meaning the water has been in there a long time and was probably quite soft before the hole.

    That said, the key thing is that FG repairs can be ground out an re-done at a later date (AKA Winter).

    a 45 year old thin hull is likely to be less than perfect in places.

    Sand the paint off 4-5 inches in all directions.

    ensure bone dry - wipe with acetone

    cut 3 or 4 piece of matting before things get messy about an inch smaller than the sanded area.

    buy some dollar store paintbrushes

    Gloves!

    mix up a small quantity of resin 3-4 oz - be very precise on the quantity of hardener and brush the liquid resin over the area, then position the cut matting and paint more resin over the top. Here's the important bit you need to work the resin into the matting so it's wetted right through - the strands will spread and almost become invisible - if they still look white more stippling.

    Should set in about 1/2 hour then repeat.

    if you have loads of resin left you can apply two layers at a time but stipple / wet each one individually. 4 layers total.

    you'll be sailable in 24 hours or less - will be ugly but strong and you can fix 'pretty' when season over.

    throw the brush - you cant clean em (Acetone works but costs more than brush)
     
  6. AndySGray
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    AndySGray Senior Member

    Thanks Sukisolo

    Seem to have posted at about the same time but similar advice :)
     
  7. Petros
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    Petros Senior Member

    you can always put duck tape over the damage and go sailing...for a while anyway.

    I would not go too far off shore until you get a permanent repair done as outlined above.
     
  8. 500Lonepine
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    500Lonepine Junior Member

    Thanks guys! Great advice.

    Two more questions.

    West systems makes a Fiberglass Boat Repair kit. It's a one stop solution. Given that it's West Systems I would guess its epoxy. Is this a good kit? If not where would I get the Polyester supplies to make a similar repair?

    Also, I'm very much inclined to do a non cosmetic fix this summer, then make it look beautiful this winter. Again, this is possible and quicker? If so what do I NOT want to do? I want to try to restore the boat, eventually. It's a really beautiful boat.

    And lastly, I'm not sure if you guys a specifically familiar, but the 505 cannot be stepped in unless on the water. How do you work in the bow of a boat of this type on dry land?

    Many thanks!!
     
  9. SukiSolo
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    SukiSolo Senior Member

    The West kit epoxy usually 105 and 205 resins. You will probably need a bit more cloth though. A lot of good chandlers sell cloth too.

    You can chock the boat up even on it's trolley to get at the bow, or turn it over. My preference would be to chock it level but high, a couple of big trestles with carpet on is fine. This way the resin wants to run down with gravity not all over the inside of the bow tank. Easier to take lumps off the outside....;)
    Tbh it is not difficult to get pretty close to a finished job cosmetically, very fast. All bar maybe the final cutting and polishing. For colour match, best to run a bit of 1200 over the 'white' to ascertain the correct colour. There are literally tens of thousands of whites.
     
  10. 500Lonepine
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    500Lonepine Junior Member

    What is the general opnion of a MarineTex Putty temporary repair ust in the affected area?

    I have one month left in the season. I'd love to get the hull really fixed right but am afraid that I'll lose weeks of saling. Could I then cut out the affected area later and really address the issue properly?
     
  11. SukiSolo
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    SukiSolo Senior Member

    This repair is easy in one day if you use polyester. Even with epoxy 2 maybe 3 days max. Only proviso is that you have 15 -20 degrees C temperature. As it is around 30 here in the UK, I sus[ect you have plenty of heat unless you are at the North of Alaska...;) On this fairly old boat it will still be perfectly sound and strong. As long as surfaces are clean and chamfered it will bond fine.

    Using the putty is going to make the proper repair more awkward so don't bother. I find it is better just to tape up if needed rather than fill with 'stuff' that will make cleaning out the repair area much harder.
     
  12. 500Lonepine
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    500Lonepine Junior Member

    Hi..

    Here is a photo of what I excised from the gash. Could you look at this and tell me what you think layer three is? This is an ex-Olympic class race dinghy, so the hull is very thin. But could it really be a single layer of cloth???

    [​IMG]
     
  13. 500Lonepine
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    500Lonepine Junior Member

    Here is a photo of the cleaned up gash

    [​IMG]
     
  14. AndySGray
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    AndySGray Senior Member

    Oh Dear

    The WTF is whats known as PEAT, very usefull in a Gro-Bag, less usefull in a boat.

    You're right in your assessment that it wasn't a single layer, the wood or balsa was part of a sandwich, and now it's turned to WTF, it isnt doing its job.

    I would be inclined to say STOP and get some advice from someone with a lot more experience in these sort of repairs who can see it in person - From the questions you've asked and the pic of the cleaned up area so far you need outside help - this is beyond the scope of a first time repair.

    If you are sailing competitively you could end up adding a lot of weight or removing more hull than can be sensibly repaired - talk to your fellow sailors, someone has to have had a collision and can reccomend a boatbuilder - trailer the boat to them and you'll pick up the boat a week later like new.
     

  15. SamSam
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    SamSam Senior Member

    That's what I was going to say, duct tape or stuff I like better is the metal foil tape.
     
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