cost of extending the life of a mid 70s fiberglass hull

Discussion in 'Fiberglass and Composite Boat Building' started by Wellington, Jun 30, 2018.

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  1. Wellington
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    Wellington Junior Member

    i dont claim to be an expert on the matter. i just know that they dont make em like they used to. after about 1960 everything you can buy became crap.
     
  2. fallguy
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    fallguy Senior Member

    This is simply not true.

    There have always been changes in boat building materials since using Wood type A vs type B. And there have been periods of poorer construction. Chris Craft, during WWII, for example, had problems getting mahogany. So they built some boats with douglas fir clears. The boats were good boats, but not as good as the mahogany versions.

    Some great boats are being built today. The hulls are even unsinkable in many cases.

    People are spending a ton of money on modern boat materials. Epoxies costing a dollar an ounce!

    The 70s were a period of experimentation using balsa cores and the failures areived years later.

    A heavy glass boat might not be all you think it is....slower, more inefficient to operate under power. Plenty of downside.
     
  3. ondarvr
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    ondarvr Senior Member

    There weren't nearly as many F/G boats built in the 60's as compared to the 70's and 80's, everybody with a 4" paint brush and a coffee can was a boat builder during those two decades.

    Old boats were both good and bad, the bad ones aren't around anymore, the good ones survived, so the good ones are what you see. Most were designed late at night after too much alcohol and sketched out on a napkin, the next day they started building it, no engineering was done, F/G was relatively cheap so adding more than needed was done frequently, plus the boat buyer didn't have a clue about the construction methods, so just about anything was tried, good and bad.

    While composites do fatigue over time and lose strength, they still hold up very well, even the early boats would still be usable once the rotten wood is replaced.

    The reason more people don't rebuild old F/G boats is because it's a lot of work and the cost can be high, if you want a project that's fine, if you just want to get out on the water the same money will get you a boat in working condition and you can be on the water tomorrow. This applies more in the US than in some other countries, here old hulls can be had for free, and newer used boats aren't that expensive, and they can be found easily.

    If you can't find a design you like in a newer boat, buying an older boat and modifying it may make sense.

    The main issue you run into is how much stuff needs to be replaced on the boat, if all there is is a hull with nothing else, then it's much cheaper to buy a used boat in running condition than an old bare hull that needs everything.
     
    Last edited: Jul 5, 2018
  4. pacificislander
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    pacificislander New Member

    Gonzo is only partially correct, early Wharrams...the "Classic' models and "Pahi" models from the 60s and 70s were built with strong backs, bulkheads and stringers. "Tiki" series introduced in the 80s are stitch and glue from the 21' upto 46' models - his latest series "Ethnic" designs are also built by stitch and glue. There have from time to time been some fibreglass Wharrams built by professional builders, Tiki 26, 8 metre, Tiki 28 and Tiki 36. There may be others.....I personally know of a Narai in Florida built with foam and glass and believe someone was selling glass (probably foam too) "Pahi 42" bare hulls down in Florida too.

    Classics have occasionally been built in aluminium (why?), other wood construction methods also.
     
  5. gonzo
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    gonzo Senior Member

    I guess I haven't kept up with Wharram. Thanks for the correction.
     
  6. bajansailor
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    bajansailor Marine Surveyor

    Wellington, have you see the thread about Oddity on the YBW Forum which has gone almost viral (if threads can go viral?) - he has bought an old hull (ok, from 1982, rather than the 70's) and intends to fit it out - despite everybody telling him that he could buy a sister ship, ready made, in good condition for a fraction of what he will have to spend to get his 'new' hull seaworthy.
    It is a good read.
    Bought a Never splashed Colvic Countess 33 on eBay, Looking for infos http://www.ybw.com/forums/showthread.php?497785-Bought-a-Never-splashed-Colvic-Countess-33-on-eBay-Looking-for-infos

    The Youtube link in the first post does not work - here is a new link :
     
  7. MurphyLaw
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    MurphyLaw Senior Member

    Yes, lots of experience, you sand the gel coat off, then you can see the glass and fibers, you look for areas where there are spider cracks, this is usually where people have stepped, you laminate with glass and a vacuum over these areas. After the spider cracking from constant flexing over many years the water gets through into the core and you will find the area is soft to touch as well, you cut these areas out and reglass. Then you spray the boat with Styrene thinners and leave for 30 minutes until it has evaporated, this reactivates the existing polyester resin, the head chemist of the gelcoat company told me to do this apparently if the surface is old it can absorb too much of the styrene that is in the gelcoat so by spraying with styrene first you ensure that there will be enough styrene in the mix when you apply the gel coat, you then respray the boat with gel coat, you then mix a cap of wax into the final coat and polish. I have had some awesome boats that are from the 70s and 80s which when I removed the gelcoat had no damage. The only way to really know and have peace of mind is to remove the old gelcoat and inspect the glass. It's very cheap in cost of materials, gelcoat is not expensive but a lot of labour is involved. If you know the boat design well you can tell whether it is a dog or not without removing the gel coat, get it for a good price, then strip and have total peace of mind. Often a boat that is only 10 years old but been abused by racing and a young family using it as a play-frame will be in far worse state than a 30 year old boat.
    Yes you can keep repairing it indefinitely, it cost about $50 to re-gelcoat a 16ft boat, if the boat is foam and glass you can always fix it up as good as new, if the boat is wood and glass you are taking your life in your hands, I have seen wooden core boats snap in two in heavy seas, the water gets in and travels to areas where there is no outer damage, foam is closed cell which means the water tends to stay local unless delamination has happened.
     
    Last edited: Jul 16, 2018
  8. ondarvr
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    ondarvr Senior Member

    You do not want to start sanding the gel coat off unless you see actual damage, removing it creates all kinds of issues and far more work.

    Styrene does not reactivate resin, I'm not sure what "head chemist" at a gel coat company told you that but it's not true. By the way, I know and have worked the head chemists of all the major gel coat suppliers and none of them would have said that. The styrene won't hurt anything, but it won't reactivate anything.
     
  9. MurphyLaw
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    MurphyLaw Senior Member

    Don't listen to expert boat people and sailors, they are like the BS Olympics. Most towns struggle to support more than a few boat builders so a lie gets its pants on and it becomes gospel. Rather experiment yourself and speak to engineers and chemists. Marine in front of anything just means they spend most of their time in the bar. You should remember that when new your boat was produced by humans, you wont see a boat with the gel coat removed without defects. A bad join in the core, a cockroach in the resin, if you want peace of mind you remove the gelcoatt and reapply. Waits for the goblins to come out and claim you cant spray gelcoat blah blah blah. The thing with gelcoat is there are so many experts around who will lecture you on what to do and what not to do, that you make so many mistakes in the early days following their BS, that by the time you figure out the truth you're loathe to share it. 90% of boats are produced with Polyester resin, they only cost $50 to re-gelcoat......do you really think anyone in the trade is going to tell you how simple and cheap it is to repair them?

    The company's chemist who helped me in the early days, belonged to one of the biggest resin manufacturers in the world. Not some gelcoat "supplier"
    http://www.ncsresins.com/

    I would have to speak to him again to remember the chemistry involved but if I remember rightly the chemical reaction relies on the styrene as the solution, like a lot of chemical reactions need water to allow the chemicals to react with each other. If the surface you are applying to absorbs any of the stryene then there will not be enough available for the chemicals in the gelocat to complete the reaction. The area where there will not be enough styrene will be at the point of contact at, the surface, the very worst place you want there to be a problem, by spraying first with styrene you ensure that the gelcoat has all the styrene it needs to complete its reaction.

    It seems like common sense to me;

    1. The styrene is the solution which carries the chemicals.
    2. If you spray onto a surface that absorbs the styrene there will be a lot less styrene on the surface with the other chemicals. This is bad, chemical bonds rely on a precise amount of molecules when they react. You will have chemicals that have not reacted on the surface when you finish.
    3. The old sanded boat with scratches and cracks will absorb styrene that a new shiny resin boat will not.
    4. By first spraying with styrene then allowing any on the surface to evaporate you ensure that at the point of contact there will sufficient styrene to allow the chemical reaction to happen.

    You could rely on Bob slapping your hull and saying "Yes Jim she's a good one" or you could remove the gelcoat and see with your own eyes.

    My biggest problem in the early days was getting supplied with dodgy resins by marine companies, I now buy direct from NCS and each chemical comes with a batch number stating when it was produced and when it will expire. I met Richard the chemist when the "marine" gelcoat I was supplied with reacted badly, I found out which company manufactured it and took it to them to test, it was WAY out of it's expiry date despite the gelcoat supplier sticking his own sticker on the container with a BS expiry date. The gelcoat supplier swore blind that it was me who contaminated it blah blah blah, despite me having tried 3 separate times to get it to work, then he claimed I had removed all his gelcoat from his container and replaced it with something else. The honorable thing would be to just say that there must have been a mistake and an employee must have grabbed the wrong container when they were decanting it but no they stuck with I deliberately decided to put them out of business on a boat that was urgently needed due to race commitments I decided to deliberately screw my reputation over and theirs, just because. The company that supplied the gelcoat is still in business a "respected" member of the marine community sending people off to sea in his rubbish boats while lecturing the sailing community on what is best.

    My best advice for anyone DIY with boats is NEVER buy chemicals from marine companies, these resins are used in many other industries, the manufacturers are the ones who supply the Llyods certifications etc. They have MILLIONS to lose if they supply a bad batch. The marine companies know they will not get sued by the time a few boat owners find out 10 years from now there is a problem. I have caught ALL the best names in the marine business not following correct quality procedures. It's a scandal of epic proportions, they are buying chemicals and not storing them, transporting them, testing them etc according to quality standards and then they sell them to you for %500 markup because they have extra quality. If you want the best always buy directly from the chemical manufacturers, you will save a fortune on cost and will never have a problem with resins there after.
     
    Last edited: Jul 17, 2018
  10. MurphyLaw
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    MurphyLaw Senior Member

    I, unlike you, have supplied logic and reason behind my actions. My head chemist is better than yours is not a scientific argument. If you don't think it works then it must because of one or two reasons.
    1. You don't believe an old sanded surface absorbs any styrene.
    2. You don't believe having the correct amount of styrene is required for the gelcoat to react properly.

    Which one is it ?
     
  11. ondarvr
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    ondarvr Senior Member

    Your comments offer no support to your perceived facts.

    I know the head chemists in the industry, I've worked with them in the lab, we've discussed bond strength many times and done the testing.

    Styrene will crosslink with itself, this forms a weaker link than when it's in the correct ratio with the polyester base. Even the lowest stryrene gel coats are still in the 30% range, the typical product sold in the retail market is closer to 40%, some are even higher.

    Please name your head chemist so I can call him/her and ask about it.

    There are ways to increase the bond strength though.
     
  12. ondarvr
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    ondarvr Senior Member

    I currently supply products to NCS, great people, Just met with them at Ibex in Paris.

    The largest supplier of gel coat to the industry is currently Polynt, they dwarf NCS. Polynt had been CCP/Cray Valley globally, I worked for both CCP and Polynt for 15 years, Polynt recently purchase Reichhold, I know the people in both companies very well.

    I had my own business for many years where we specialized in refinishing all sorts of composite and metal products, bond testing was a huge part of our success. So yes, when it comes to refinishing gel coated parts with gel coat or other products, I have about a 50 year personal history of experience. This includes 25 years of doing it hands on daily, and then another 25 years of lab testing and instructing customers as a technical rep for the gel coat and resin companies.

    Gel coat to gel coat bonds typically hold up very well, but they aren't as strong as a resin to gel coat bond, styrene bonds tend to be weak, brittle and not as water resistant. Gel coat bonds tend to be weaker than resin bonds because much of the base resin in the gel coat is used up in wetting out the pigments and thixitropes in the mix, so there's not as much left to wet out and bond to the substrate. Regular resin has the thixitropes to increase viscosity, so you're still battling them a bit, but it's much better than straight gel coat. An infusion resin has a very low viscosity so it wets out the surface and can penetrate deeper (if applicable) than gel coat or resin. (all of this pertains to post coating, not in-mold use)

    If the concern is a better bond to an old bare laminate, the best option would be a using a VE infusion resin as a primer, spread it very thin right before gel coating the surface, this would give the best possible bond.

    Reichhold also makes a bond enhancer called ATPRIME, it works very well in many situations.
     
  13. MurphyLaw
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    MurphyLaw Senior Member

    As I said better to remove the gelcoat and reapply to the resin

    In other words the more penetration by the gelcoat the better the bond. The gelcoat uses the styrene as the solution that carries it, if there is a deficit of styrene then there will be less penetration. Talking about resin to resin bonds is a straw man argument, we are talking about gelcoat to resin bond and if the surface absorbs styrene there will be less styrene available to allow the gelcoat to penetrate. Anyone in doubt should take a piece of wood and spray with gelcoat and then spray first with styrene and then gelcoat, see with your own eyes which adheres better. Another good example would be contact adhesive, if you apply to a porus surface and then join you get a weaker bond, but if you first apply and then let evaporate off then reapply and join you get a much stronger bond. And in your own words the weakest bond is a gelcoat to gelcoat bond, so much for not removing the existing gelcoat.
     
  14. ondarvr
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    ondarvr Senior Member

    I may have not explained it clearly.

    The gelcoat won't bond much better to the laminate than to plain gel coat, gel coat in general just doesn't bond as well as resin no mater what the substrate is.

    Styrene is a component of the gel coat/resin, it's the weakest component, and adding more doesn't benefit either product, just degrades it. Coating the surface with styrene and letting it evaporate doesn't reactivate it, it may clean the surface like most solvents would, but if you let it evaporate there isn't anything left to lower the viscosity of the gel coat even if it did help it penetrate deeper. Thinking the styrene itself may crosslink and increase the bond is wishful thinking.

    Removing the gel coat opens up the laminate and all the small defects in it from the original build, plus the disturbed fibers, spraying over this surface can be difficult and create extra work, plus when you remove the gel coat the surface can become very uneven, so now there's extra work in fairing the surface.

    If there's actual damage to the gel coat and or laminate, then yes, you should remove the gel coat and repair the laminate, no damage, don't remove it.

    What it comes down to is that if removing the gel coat is what you like to do, then by all means do it, but don't expect the results to be any different, it just creates more work.

    This is sort of like thinning epoxy, it sounds like a good idea, but the chemistry doesn't play out that way.
     
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  15. MurphyLaw
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    MurphyLaw Senior Member

    I'm well aware that you want as little as styrene as possible, I always spray with the largest nozzle I can get and the same chemist told me that was the aim.

    Meanwhile back on planet earth, the whole art to doing a good job is knowing how much styrene to add to do a good job, if its 33 degrees outside a lot of the styrene will flash off before it even hits the surface, I mean this is sailing not space rockets, you do the best job possible in the conditions available. You can talk all day about the right mix but if you cant get that mix onto the surface then it's pie in the sky. Then when anything evaporates it also cools, so as the styrene travels from the nozzle to the work surface any that evaporates also cools the stream, so by adding more styrene on hot days gives you the same mix on the surface but cooler which is a good thing because anything over 27 degrees is difficult. When you are spraying you can tell whether there is too little or too much styrene but depending on how hot the work piece is and how hot the air around it will govern the correct amount of styrene to add.When you spray the styrene first and let it evaporate from the surface, it only evaporates from the surface, it doesn't evaporate any absorbed styrene immediately. It means when you spray with the gelcoat, no styrene will be absorbed by the work piece.

    I've been around the block too, the people who sell these chemicals and the directors of companies that use them are not the ones applying them. I bet if I visited a boat shop and asked the guys spraying the stuff whether they ever used boatdesign.net that 99% would be negative. The fact is if you want to be the best and innovate then the worst people to associate with are the experts in the field, they are no longer invested in the science but in their reputations. I get as much science as I can on the subject then take it out into the real world and experiment. I have pieces all over my yard that I have sprayed and I check every year how they are holding up, I am just as keen to see what doesn't work as what does. I volunteered to do all the repairs at my sailing club at cost, I told them I was just looking for the experience and could only guarantee I would do my best but a lot of people figured I would do a better job than they themselves could afford to, haven't had a single comeback and I repaired boats that delaminated into 2 pieces, my toughest best job went under the pier about 4 months after I finished it and it held together, shame because that boat was at least twice as strong and stiff as one new from the manufacturer and was repaired to be an off-shore racer and I was hoping to hear about a long life on the ocean.

    I once had a boat that was only 5 years old and it looked perfect, removed the gelcoat and they obviously had a real bad day at the boat yard when it was produced, the resin was full of air-pockets, it looked like champagne, it must have been only a 3rd of the strength of a properly produced boat. The owner got rid of it. I don't know about where you are but here any rescue you call for could take a day before they found you, if they ever found you, nobody in their right minds goes racing in a boat that is not structurally sound. Probably half the boats or more in any boatyard would break if you took them out and raced them offshore, if you want to race boats offshore you have to be sure they are structurally sound which is why you should remove the gelcoat, you just never know for sure until you do. How much extra time is too much when it comes to your life?

    I'm looking at your resume that you posted but I cant find "sails overpowered boats in offshore races" so I wont be asking you for an interview :p
     
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