boat stuck in mould

Discussion in 'Fiberglass and Composite Boat Building' started by whacker82, May 25, 2012.

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  1. tunnels

    tunnels Previous Member

    Congratulations and well done !!

    For a first effort you take the prize for the best stick up i seen for a long long time .
    you can see first hand at what can and does happen seemingly for no apparent reason . if you alread taken one boat out then something you did or used is differant from the first time !! stay awake totill you find what it was !!

    Two things immediatly spring to mind ! because you are brushing you gelcoat the wax is not compatable with your Gelcoat .something in the gel is softening and eating the wax its the same senario i had in Korea .
    second the Catalyst ratio needs to be higher to gel quicker and stop the gel from eating the wax .
    Definitly you need pva and spray it on !! Beg , borrow , or steal a spray unit from some one some where . Follow the instructions to the letter i posted and i am 99% sure it will solve your problems !!can still use the wax you got and the pva will act as the barrier between the two !!

    Now mould repairs !! you were lucky you did what you did and take the boat out in bits The mould looks worse than it probably really is !!.
    Its a block sand job and carefully sand the surface smooth again . just about all of the white stuck to the molds surface will vanish as you sand the mould, so take care and do it quickly but carefully .
    320 Wet and dry sand paper will get it done in short time then go up through the grades to 1200 then cut and polish the surface .

    Get the bits of boat you cut out and get some clear really close up pictures !! look for what could be brush strokes or brush marks and then its a possitive conclussion the wax is at fault !!
    Do you have a glass supplyer close by?? try to find some soft wax usually made by Johnstons waxes !! get some and try it on one of the cut outs and apply a couple of coats !! rubbed well into the surface and let it dry for an hour before polishing off the surface . then gel coat it !part at 1.5% catalyst and another place 2% catalyst ! dont need to glass it just peel the gel coat off and see what happens ! easy or hard to get off ?? good or bad ?? thats the question !!. use your old wax and do the same on anothe piece of boat off cut but wipe a coat of PVA and test that as well same way !.
    Its a process of positive elimination so you know in your own mind what you can do and should do and what dosent work together !!you can do all these things inbetween sanding the mould and have your answers by friday !!

    Just thinking about your mould you dont have a frame around it ?? thats a good thing to get the product out, simply twist the mould and it should just pop effortlessly and 100% clean just roll it over and drop the boat on the grass .

    Lessons in life always come with a heavy price tag !! so learn from what happened and new products !! test before you use them !! most supplyers just want to peddle there wares dont believe everything thay tell you and take special care !! i wish i was standing where you are right now !!!

    Whats the last picture GEL COAT FILLER ????? WHAT IS IT AND WHAT DOES IT DO ?? WHY YOU USING IT ??

    Smile :p:p you have learned something new and so hopefuly will others on this site :):) look forward to your conclussion of testing the differant things and waht works and what dosent !!;)
     
  2. whacker82
    Joined: Sep 2011
    Posts: 146
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    Location: ireland

    whacker82 Senior Member

    thanks midnitmike, needed that :)

    here are some more pictures of the damage, all the fiberglass is out of it now. take a close look please at the damage as i want to fix it up again and start making new boats.
    in some parts of the mould there must have been no mold release wax cause some of the paint stayed on the mold especially near the transom.
    this is beyond me as i was convinced that more then enough wax went into it, but obviously not.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
  3. whacker82
    Joined: Sep 2011
    Posts: 146
    Likes: 2, Points: 18, Legacy Rep: 33
    Location: ireland

    whacker82 Senior Member

    [​IMG]

    [​IMG]

    [​IMG]

    ok thats it. now im gonna ask for one more wish, i need as much advice as possible on how im gonna repair this mould and have it like new once again,
    how do i do it,
    where will i start,
    what do i use.

    big ask but im not going down without a fight on this im too far in now.
    thanks again guys every post reply is much appreciated, i think id have done my head in if it wasent for all the advice im getting here, makes me wanna succeed even more. ;)
     
  4. midnitmike
    Joined: Apr 2012
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    Location: Haines and Juneau

    midnitmike Senior Member

    Hi Whacker,
    If you notice most of the problem areas are inside raduises, and I suppose there's good reason for this. They are without a doubt the hardest places to work...so it naturally follows that's where you'll find 'em. Just like Tunnels said you're probably going to have to sand these areas out doing as little damage to the surrounding surface as you can. You might even consider masking off some stuff just so you don't make more work for yourself accidently.

    When faced with work like this I try and make sanding blocks that help me concentrate my sanding efforts to just the high spots, but they have their limits, so I always end up resorting to hand sanding toward the end. You can develop a real feel for those little high's and low's that are all but invisible to the eye.

    I used to try and deal with just one area at a time, but I found my progress was way to slow, so now I use a slightly different approach. Sand out every nook and cranny with each progressively finer paper. At the same time mark all your low spots and begin building them up as you go (I use bondo or spot filler most of the time). Some of those deeper nicks and gouges could use some of that gelcoat filler you have, and it's a better use for these purposes then your original idea. Once they're up to the mold surface you'll block sand them smooth just like everything else.

    Once I start getting close I tend to use some sandable high build primer because it's so much easier to fair then a harder material. Eventually (after a lot of sanding) you'll have it to the point where you're ready for wax, and this is where you need to take your time. One coat of wax per day...no more. Look at this way you spent almost a week to get these apart...save yourself the frustration and spend that week doing something else.

    If you can get your hands on some PVA then apply that after you're done waxing. If you don't have a compressor and spray gun then beg, borrow, or steal one for an hour...they'll hardly notice they're missing...lol. For your first go round you can wipe it on by hand, but don't be surprised if the finish isn't what you expected. It may not give you the perfect finish, but the satisfaction of having your first boat out of the mold should more then make up for it.

    You're doing good!

    MM
     
  5. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    18 to 20 mils would be the correct gel coat thickness.


    If your gel coat isn't hard after two hours then this can be another part of the problem. Gel coat should be hard in hour or so and ready to laminate on, if it's not you need to change the shop conditions or your process.

    The longer the gel coat sits on the mold before it cures, the higher the chance of it sticking. The styrene in the gel coat will start attacking the mold release as soon as it's applied and it can only hold up for so long.
     
  6. whacker82
    Joined: Sep 2011
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    Location: ireland

    whacker82 Senior Member

    i was asking on you tube about the gel coat, they were saying 8 to ten hours before applying the next coat. i also read that gel coat on big boats is fine to be 20mil thick, as there is less flex. but on small boats 1 to 2 mil is fine due to the boat flexing so much it should not crack.
    im very confused
     
  7. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    The other thing is, when you gel coat the mold do you leave it upright, or do you tip it on its side?

    Styrene fumes are heavier than air, so they settle in low areas, they will also inhibit the cure of the gel coat, so they need to be removed. Tipping the mold on its side or pointing a fan in it will remove the fumes and allow it to cure properly.
     
  8. whacker82
    Joined: Sep 2011
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    Location: ireland

    whacker82 Senior Member

    always up right with me. and in a small shed fumes can get very strong. ive seen on youtube them putting on the gel coat by tipping the mold, just didnt know why
     
  9. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    Gel coat needs to be in the 18 to 20 mil range to cure properly, on some types of boats they try to use as little as possible to save weight (canoes and kayaks), so they go a little thinner, but they can run into problems. Depending on the exact gel coat and the exact methods being used, some builders can get down to 12 mils or so, below that problems are very common.
     
  10. whacker82
    Joined: Sep 2011
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    Location: ireland

    whacker82 Senior Member

    thats alot of gel coat, i was using 3liters for the two coats on my mould was coming out about a mil thick,
     
  11. wet feet
    Joined: Nov 2004
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    Location: East Anglia,England

    wet feet Senior Member

    The gel coat filler that was used to repair the mould is a reasonable product for minor repairs to existing mouldings.It is a bit different to tooling gel and looking at the mould I would have doubts about whether it was laid up with tooling gel.The repair to the mould will be fairly time consuming,but at least you have a mould to work with and it could have been worse.
    Ignore the comment about 18 to 20 mil,its an oddball American measurement and not related to metric dimensions.One European mill would be a fairly heavy coating and your quantities are not so far out.
    One final thought on this thread and indeed this entire forum-we constantly have amateurs coming along and asking questions and they get answers.Is it any wonder that so few of us in the business get rich when we give away our knowledge so freely?
     
  12. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    True, a US measurement.

    One gallon (3.78 liters) will cover 80 square feet, what are the dimensions of your mold.
     
  13. wet feet
    Joined: Nov 2004
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    wet feet Senior Member

    You evidently didn't read my comment about oddball American measurements!In Europe-and the poster is from Ireland-one mil is one millimetre of which there are 25.4 to the inch.There are very few countries still using imperial dimensions and not many of them are in Europe.One millimetre would be a very heavy gel thickness,at least here.
     
  14. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    I was typing at the same time you were, didn't see yours until after I hit send, changed it after that.
     

  15. whacker82
    Joined: Sep 2011
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    Location: ireland

    whacker82 Senior Member

    Wet feet that's very true but its the love of boats thats in us and anything boat related will trigger us into talking about our love of them. Even if it means telling some secrets. PLus as you said I'm from Ireland so I can't be taking any business away from ye:p

    But seriously I'm very greatful and I don't think I've said thanks enough here to all that's helped, I never expected this much help and advice. So thanks again all. :)
     
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