Can anyone help !!

Discussion in 'Fiberglass and Composite Boat Building' started by rich99uk, Jan 5, 2006.

  1. rich99uk
    Joined: Jan 2006
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    Location: portsmouth

    rich99uk Junior Member

    I Have taken all the gell coat off the botom of my boat im down to just fiberglass
    Eventually when done i will be antifouling the bottom of the boat.
    What I need to know is what i can put in replace of the gell coat i took of and where can i get it. what Epoxy do i use do I need a sealent of any kind to coat the fiberglass with ????
    If someone would be able to explaine to me exactly what I need to do and what resins ect i need to get i will be very gratefull !!!

    Many Thanks for your help
     
  2. zerogara
    Joined: Aug 2004
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    Location: Preveza

    zerogara build it and sail it

    Replacement of gel coat with epoxy barrier

    1 What side of which ocean are you? There is more than one Portsmouth and are all ports :) If in US West System has a solution for you and booklets of instructions on pretty much any marine supplies store. There are other companies with good stuff too, that's the easy answer.

    2 Your subject is inappropriate, a thread should be relative to your inquiry.

    3 I think your subject would be more related to materials and not boatbuilding.

    4 Use the search button above to the right and you'll get tons of answers and disputes.

    How bumpy is your surface? Why did you remove all of the gel coat? Where there alot of big blisters? Cracks? Major damage evidence? What size and type of boat is it? Flat surfaces are 1000 times easier than curved ones.
    Have you had a surveyor, or someone knowledgable of laminate integrity, check the hull?
    Is the hull dry now? If it is moist (can be checked with a hydrometer) don't put anything on it till it dries. Otherwise epoxy will trap all the moisture in the hull terminally.
    I'd be happy to do this job but I'd hate to take gel coat off. Usually the one that takes it off gets to do the fun job ;)
    2 problems you may encounter. The good stuff that will go on will be hard to sand, so it has to be put on skillfully to minimize sanding. If it is easy to sand then it is not good stuff. Waste some material on a an other surface (scrapped piece of fiberglass or old dinghy) and practice. Try to sand pure epoxy resin, and then add microballons silica or what ever filler to the maximum you can mix and sand that part too. Now try to scrape them off.
    See what I mean!
    If it is a small boat you should utilize gravity to keep the stuff on the surface. Obviously it is too expensive to turn a 30'+ boat over to work on it!

    Let us know some more!
     
  3. rich99uk
    Joined: Jan 2006
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    Location: portsmouth

    rich99uk Junior Member

    Hi I am from The UK
    Thu hull was covered in osmosis millions of tint blisters which did smell when you drilled them out and the fiber glass was very wet inside
    The hull is not yet fully dried but i am just getting my materials ready
    The boat is a 22ft fishing boat rather heavy at 2.5 ton so i will probaly leave it up the right way he he.
    So can i confirm do I just coat the bottom with epoxy resin ? Does it have to be a particular type. do i need to coat the fiberglass with anythink before hand
    Thanks
     
  4. Penfold
    Joined: Oct 2005
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    Location: GBR

    Penfold Junior Member

    Hi Rich
    Covering the bottom in epoxy is possible but at this time of year not without it's risks (it can take days to go off in less than 5deg c like we have around now and absorbs water all the time it is curing) This can prove to be a very expensive waste of time and you're right, if the epoxy isn't 'keyed' in correctly to it can be very difficult to do as well, particularly if the boat has had osmosis.
    Thankfully the major paint and epoxy suppliers have cottoned on to this problem - at least for commercial use, and you can buy a couple of epoxy primer/sealer paints, which as they say on the tin are epoxy based formulation so when they go off are seriously rock hard. Harder in fact in my experience than the original polyester gel coat - but unlike just coating with epoxy they have the solvents in them to assist the cure and they are formulated to apply by spraying, roller or brush. You can then use any top coat paint over them - or antifoul.
    Ideally we would start with a coat or 2 of SP's Eposeal which is a specially solvented epoxy base - which soaks up into the original surface and stabilises the old glass fibre, then coat with 2 good coats of a top quality epoxy primer like Awlgrip 545 or one of the International 'Interline' products (These are difficult to buy in small amounts but we can supply all of these down to a litre) A couple of coats will replace the thickness of your average gel coat and give you the perfect key for top coating and antifoul. Depending on the condition of the hull, the Eposeal may not be required though.

    OK, to actually do the job we would always start with a cheap and simple tent around the bottom of the boat (a roll of plastic from B&Q and a couple of rolls of parcel tape will do a 22foot boat easily) go round the boat a couple of times if you can to insulate the space as well as you can. We would do this even indoors at this time of year - In the tent you could do a lot worse than a small fan heater and a cheap dehumidifier running for a week or so to drive out the moisture (really doesn't even need to be run flat out, the plastic keeps the heat in well and if the dehum is in the right place it will soak up a lot of water) Once dry, abrade with 80 grit on an orbital to flatten and key the surface, repair any damage and generally make sure you are happy with the hull - this is the last time you will see it for a long time - getting an inspection done at this time isn't a bad idea - it can get your insurance down if you are running the boat commercially (I can help you out with hull surveyers in the pompey area i think)

    Get rid of all the dust (either hoover or open the ends of the tent and let the breeze through on a DRY day!) seal it up again and run the dehum and heater for a couple more days to get the surface as clean and dry as you can - carefully using a solvent like acetone to make sure the surface is ready.
    Eposeal goes off quite quickly but takes a long time to be ready for overcoating (10 days) so leave the heater on a timer to run overnight to keep this time down and to prevent against frost during cure. We would roller the 545 or Interline (there are a couple of others) and then pick your topcoat colour!

    As I mentioned it can be difficult to buy some of these products in small amounts (some interline products come in 25kg tins minimum!) and you won't need a large amount for this job. Here's a quick plug: We supply kits to people doing this sort of job. The kit contains full instructions, protective gloves, dust masks mixing pots and sticks, USEABLE quantities of the products like 5kg instead of 25kg! and even the plastic to make the tent! So instead of getting this from here and that from there and forgetting the solvent and having to rush around, we supply the whole lot in a box ready to go!

    If you need any advice or want some prices on materials, give me a call on 01394 385838
     
  5. wdnboatbuilder
    Joined: Nov 2005
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    Location: Cape Coral Fl

    wdnboatbuilder Senior Member

    Don't use WEST SYSTEM
     
  6. zerogara
    Joined: Aug 2004
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    Location: Preveza

    zerogara build it and sail it

    Why? Not that I have any interest to sell W.S. but I'd like to hear the reasons. I know that thousands of boats have used it. I've heard horror stories from wooden boats but not FRP boats.
     
  7. Penfold
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    Penfold Junior Member

    I think West Systems work very well provided you are careful when mixing the resin and hardener in the right ratio. We use them all the time for work on wooden boats and find them just as good as any other product - better in fact than most at this kind of work. Get the ratio wrong and you can expect problems, but that's the same with any system.
     
  8. rich99uk
    Joined: Jan 2006
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    Location: portsmouth

    rich99uk Junior Member

    I have this huge tin off Epigrip L524 Modified Epoxy can I use this in the process at all that penfold described if so what would be the process ?
     
  9. wdnboatbuilder
    Joined: Nov 2005
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    Location: Cape Coral Fl

    wdnboatbuilder Senior Member

    I just find that WEST cures too fast and it also heats up too hot and I feel it becomes brittle, just my opinion but as you all know opinion are like *******s, everybody has one and they all stink.........
     
  10. zerogara
    Joined: Aug 2004
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    zerogara build it and sail it

    I know they have different hardeners, slow/medium/fast, are they all brittle and fast, compared to what epoxy?
    I think one place where they excel is that to people with limited knowledge who want to make a small repair they provide the material (at a high cost) and knowledge to do just what they need. Also by their method of their material and plywood the average Joe can built a little dinghy in their backyard not knowing much of naval architecture or composite science.
    In boat repair, and by marketing to the boat owners, if one repair outfit uses West System to repair rot, FRP cracks and holes, they use the good stuff. The rest who might use a less known to the public epoxy they are cheap skates! And the majority of boat owners are firm believers to the "you get what you pay for" philosophy. And it definetely costs to have a firm name out there associated with epoxy.
    Outside North America though this fame doesn't exist and SP is moving in their turf!
    I've used epoxies which were obviously less brittle than WSys and were nowhere close affected by sunlight as WS is. The stuff turns yellow overnight if exposed to the sun.
     
  11. wdnboatbuilder
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    wdnboatbuilder Senior Member

    At the time I did my test,I was comparing it to System 3 epoxies. I took a 6 oz. Cloth and coated with WS and S3 came back the next day and folded the 2 pieces in half WS broke and S3 flexed and flexed and flexed. Gougan Bros wrote a great book. I now use Raka Epoxies and yes they are less expensive but not cheap. Another quailty I look for is how much blosh is it going to put out, Raka None WS some but not as bad a some epoxies I have used.
     
  12. rich99uk
    Joined: Jan 2006
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    Location: portsmouth

    rich99uk Junior Member

    Ok guys so bearing all the above in mind what materials would you all sugest I use to replace the gellcoat on my boat. I am new to this but when i do it i want the job to be good and last. If you guys could give me a breakdown of what materials to use and in what part of the process I would be really thanksfull. I have Epigrip L524 Modified Epoxy Can i use this if so were about in the process and what do i need to use in conjunction with it.
    Thanks Rich
     
  13. zerogara
    Joined: Aug 2004
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    zerogara build it and sail it

    http://www.leighspaints.co.uk/Products.asp?ProductCode=L524 http://www.the-iron-dutchess.com/TL524.pdf

    I found those two links with info on your epoxy as I'm not familiar with it. The coverage seems to be 5 sq.m /lit that's about 180 sq.f / gal
    What I read though is that it may be meant for metal underwater coating and I'd check with the manufacturer on whether it is apprpriate for GRP (most likely it is). It is definetely a barrier coat and can be applied in several layers.

    Focus more on your surface preparation and how dry the hull and environment is before you apply. Winter time in the UK is very prohibitive for outdoor work with epoxy or any resin. You can mix chopped fibers, or other additives to fill irregularities and then coat the finished surface.
     
  14. rich99uk
    Joined: Jan 2006
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    rich99uk Junior Member

    Ok great cheers what would u recommend to be the first coat to the fiberglass be the sealent ? or do i not need one ?
     

  15. safewalrus
    Joined: Feb 2005
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    safewalrus Ancient Marriner

    Rich please remember that all this epoxy **** can do extreme nasty things to your body - ALWAYS READ THE SAFTY INSTRUCTIONS AND ABIDE BY THEM! Especially if doing any of the work inside! (remember any plastic tent is classed as inside!) If you don't there's a good chance you'll end up like a Good 'Scummer' (Dead!) This will spoil your entire day!
     
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