Need help identifying materials of layers in restored fiberglass boat

Discussion in 'Materials' started by Nidza, Nov 26, 2017.

  1. TANSL
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    TANSL Senior Member

    Thanks again, Gonzo. I believe that the systems of years ago had sufficient accuracy for the analysis that, in this case, would be necessary. We only need to know the grams of fiber per kilo of laminate (without counting the resin). Not much precision as you can check, 1/1000.
    What I want to say is that, for example, with the mass spectrograph it is impossible to know if it is unidirectional, biaxial fibers, etc. It is also impossible to know the manufacturing method used and some other variables or procedures that are essential to determine whether a schedule is suitable or not.
     
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  2. gonzo
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    gonzo Senior Member

    Perhaps you should read the title of this thread. He is asking to identify materials not lamination techniques or shcedules.
     
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  3. TANSL
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    TANSL Senior Member

    You're right, friend Gonzo, I've read the title of this thread again and it occurred to me to remember that the mass spectrograph can not detect the glass, which is a composite material, it could only determine that there is silica sand, sodium carbonate and limestone.
    If you agree, so as not to end up as usual, we could leave this conversation, okay?
     
  4. gonzo
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    gonzo Senior Member

    The glass does not need identifying. He asked about the resin.
     
  5. TANSL
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    TANSL Senior Member

    As one of my friends says : "Perhaps you should read the title of this thread"
    Title of this thread : Need help identifying materials of layers in restored fiberglass boat
     
  6. Nidza
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    Nidza Junior Member

    Well, you are both right that the title can be interpreted in two ways, but I was more interested in a way Gonzo interpreted it so that I can apply next layer of proper material and have adequate bonding in the future, well let's say rather layers on macro level than micro level. I can't do much on micro level. Although, it is very interesting where it has led your conversation. I am currently "playing" with spectrometers, but for EMI/EMC purposes and in optical lab with colimators, but not with mass spectrographs, I can see that we all have fun in our work domains and laboratories :).

    I did not have the time yet to play with that "plug" sample, but when I do I will cut it through horizontal macro layers, and take a photos of seen structure (sand it if needed for better view of structure) and also burning the parts of samples is an easy task. What are the smells of burning epoxy and burning polyester, how would you describe them so I can differentiate?

    Someone have asked if the plug is from the centerline (of boat I presume), it is not, in the middle is the keel, it is about 0.5 to 1 meter to the side from the centerline. It is old tech, probably hand layup, built in the second half of 60s. The external layers added in restoration process during the 80s are the ones of my main concern.

    Now, back to the laboratory, everybody to its own :).
     
  7. Nidza
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    Nidza Junior Member

    Yes, the question was from the Redreuben
    I presume that when you have said that mould was rotated from one side to the other you meant on something like this shown in the following photos (old photos from the factory in which the boat was manufactured, just shown molds are of different boat models):

    Mold_01.jpg Mold_02.jpg
     
  8. TANSL
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    TANSL Senior Member

    @Nidza, I am going to try to justify myself because I do not want anyone to think that I am an agitator who enjoys destroying this thread with useless arguments. Perhaps you can interpret the title of the thread in several ways but what really interests the repairman is to know the existing layers and the configuration of each of them. This is a very typical problem when trying to repair FRP hulls. As far as I know, it is a problem that does not have a solution, or at least a solution that can be applied in the practice of repair shops. I will try to explain why I say all this knowing that many people already know perfectly what I am going to say. I do not want to give lessons to anyone, they are things perfectly known by professionals in the sector.
    When working with composite materials, the chemical composition of the laminate does not have much value. It is necessary to know the number of layers and the composition of each layer. It is also necessary to know if the fiber that exists in each layer was in the form of mat or fabric and in the latter case if it was a unidirectional, bidirectional fabric ... All this, in my opinion, is impossible to know.
    To calculate the mechanical properties of the laminate, as better as possible, is also necessary to know the procedure used in its manufacture, laminated by hand, by infusion, ...
    Since it is not possible to know the thickness of each of the original layers, if you cut the sample by means of horizontal cuts, you can not assure that each of these rings corresponds to a specific layer, it is possible that parts of different layers have been included in the same ring.
    In addition to all this, the thickness of the sample is not definitive in terms of its suitability to withstand panel loads. There may be a very thick laminate and totally inadequate to withstand those loads.
    As I said before, this is a problem that I do not know the solution to. That's why when I read that there were several methods to solve it I felt really interested. I check, disappointed, that my hopes were vain.
    In this forum there are people very knowledgeable about these topics so they could correct me and add information so that we can all better know the existing possibilities.
     
  9. ondarvr
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    ondarvr Senior Member

    When you burn a laminate you can identify each layer as to what is and it's weight, it's a fairly crude but accurate test.

    But in this situation it's totally worthless information, so it's not even worth discussing.
     
  10. TANSL
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    TANSL Senior Member

    Naturally you have much more knowledge, more practice, than me in this subject. I do not doubt at all what you say, although I am pleasantly surprised to know that it is possible to distinguish one layer from another. It is a subject that, as I have repeated twice, I find very interesting. My news, by conversations with other experts, was that you could know the weight of the glass but nothing else. The other parameters that, as I mentioned in my previous post, are necessary for a good engineering of the laminate, I think that you can not find out if the original laminate has been done correctly.
     
  11. gonzo
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    gonzo Senior Member

    When you burn it, you can identify the chemical composition of the materials.
     
  12. ondarvr
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    ondarvr Senior Member

    When you burn it the glass is left intact sitting there just as it was before lamination, you can easily identify CSM, roving, biax, etc.
     
  13. TANSL
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    TANSL Senior Member

    Okay, I will not discuss that and I appreciate your expert opinion.
     
  14. Nidza
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    Nidza Junior Member

    No need to justify, I would rather call all this conversation the brainstorming or the debate and everybody prosper from that i.e. by learning something new or correcting if he/she has learned something incorrect (in general, not pointing at anyone by this). I, as the end user and the one knowing the least about this field of science, will also prosper with one or more most practical techniques/ways to test what I can, in my life time, in a way that I can afford.

    Since the thread has so much interested the members in other, more scientifical direction, if anybody wishes to experiment, I can send you a piece, I have some more pieces of different boat structures while I was integrating different equipment on the boat, but in that case, it would be nice that the results of experiments are shown here and the knowledge shared.

    In my case, it is a recreational boat which I can afford and I do not plan to reconstruct or re-engineer it from the beginning, but if some part of underwater hull is being scratched or it develops some crack, I would like to know what resin to use that will bond "properly" to the structure of the hull and be watertight so that boat is usable in following years or hopefully decades. I had one crack, since it was shortly transported on the trailer without shock absorbers (trailer for use only inside the ports) and it was fixed by a repairman with a couple of layers using acid resistant polyester and I am not sure now mat or roving, with sending between each layer of course, then closed it with two layers of polyurethane primer paint and then 3 layers of anti-fouling. And after one year, that is OK, but I want to know if it is correct way. Since in the 80s hull was "painted" with epoxy, and according to information available on the internet epoxy protects the hull better then the choice of a repairman. Mind that the fiberglass repairman in my country is currently not a science guided man, rather one in underpaid trade. Personally, I am more interested in all other aspects of boating than fiberglass and painting, but I am learning those aspects, too because that actually is the most often needed on fiberglass boat according to my humble experience and protecting the boat hull long term.
     
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  15. PAR
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    PAR Yacht Designer/Builder

    You seem to be over thinking this problem. By appearance she looks resin rich, which simply means you can improve on this with the next layup. Make the next layup as thick as what was previous, but with a better fiber/resin ratio and you'll have a stronger laminate, assuming you've used techniques that will insure a better ratio.
     
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