Epoxy from China

Discussion in 'Materials' started by Jim beam, Jun 1, 2022.

  1. Jim beam
    Joined: Jun 2022
    Posts: 13
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    Location: Africa

    Jim beam Junior Member

    Hello boaties,

    I was reading a thread here on the weekend......

    "Thickness of a sandwich composite panel, and a few other related questions? "

    which was quite interesting to me. In the thread the Dutch guy in Thai mentioned getting foam from a Chinese company, UTEK.

    So I went and googled UTEK and found thier website. I have been having an email conversation with them today about various supplies.

    One of the items I need to source is epoxy. I am in Africa and the only place I can get epoxy here is from South Africa and that comes at a fairly steep price. Given I need to purchase approx 1000 ltrs of epoxy and I need it trucked about 3500 Klms to where I need to laminate, I had the thought it might be better to just get the epoxy from China.

    (A little back story here : I am planning to do a fibre glass (polyester resin layup to build up some thickness then a final laminate of epoxy over that) refresh over some old fibre glass tanks I laminated 21 years ago - so I bought a ton of supplies from South Africa for this (but not the resin till I am ready). Turns out the CSM I bought came in from China anyway. So this got me thinking - Why buy through the South African retail chain only to have to ship the stuff through several countries to get to me here when it seems most of it is coming from China anyway? If the stuff I bought only came from China anyway , why not buy direct and get a better price level?)

    So it turns out that UTEK have the glass cloth and peel ply that I want so I can definitely get that there ( I Have South African quotes that are 4 times + the price of the Chinese stuff through UTEK)

    However I am not sure about the epoxy. Is the Chinese blends of epoxy OK ? I have no experience to draw on here. I was told that all of the epoxy part a (biphenol A) is the same stuff anywhere in the world as only 2 manufacturers actually make the stuff worldwide. The secret sauce for epoxy is all in the part b (hardner). I dont know if this is true or not but if it is then it would seem the real question is, how good would Chinese epoxy part "B".....be ?

    I am not laminating a plane or a boat here - these are water tanks (but I come here for lots of good info on laminating in general). So even if the Chinese stuff is not up to West standards it may well be OK for my needs. I just dont know. Hence reaching out to the community here to seek advice on this.

    The other issue is shipping epoxy. I have learnt today that it is a:

    class 9 dangerous good, UN 3082 , PG III for shipping purposes.

    Normally this would not make sense but I have a container coming to me from China with some other stuff (a Co2 laser CNC machine, bamboo plywood, solar panels and a few other things) I can fit about 6 drums of epoxy in the container along with many rolls of glass cloth and peel ply. Container is coming anyway so may as well get as much as I can into it and I was only going to buy this stuff from South Africa anyway.

    However I dont want to buy 6+ drums of epoxy if its not good stuff.

    No way to know till I try it or someone who does know could give me some advice about it.

    For the record the epoxy is nearly half price compared to South African supply and the seaport is only 1100 klms away from me if the epoxy comes via ship Vs 3500 Klms from South Africa via road.

    It all makes sense if the epoxy is any good.

    I think I will get the glass cloth and peel ply regardless since the last lot I bought came in from China to South Africa and through the retail chain marked up a number of times till I got it. But the epoxy resin...I just don't know whether to try it or not

    Thoughts ?




     
  2. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    Welcome to the Forum Jim.

    There is a huge wealth of experience on this Forum, especially re epoxy, and hopefully somebody here will have had a positive experience with the Chinese epoxy that you are considering ordering.
     
  3. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Why don't you get some air mailed to someone who can verify the quality?

    Do you have a datasheet even? Side by side compare it
     
  4. Jim beam
    Joined: Jun 2022
    Posts: 13
    Likes: 1, Points: 3
    Location: Africa

    Jim beam Junior Member


    Thanks for the welcome bajansailor. I have been reading here for years now. As you say some very knowledgeable people here. I have learnt everything I know about epoxy reading here.
     
  5. Jim beam
    Joined: Jun 2022
    Posts: 13
    Likes: 1, Points: 3
    Location: Africa

    Jim beam Junior Member

    Hi fallguy,

    Thankyou for your response.

    2 things.

    I dont know anyone I could have it sent to , and secondly given it class 9 dangerous goods rating, can it even be shipped via air ?
     
  6. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Worst case, send it to yourself. Otherwise, find a materials lab that can do coupon testing.

    You can do some simple tests of your own.

    @gonzo may know of a couple labs

    as to air mail, perhaps requires sending the parts separately; each item, on its own, is fairly inert
     
  7. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    I'm not sure of exactly your need for epoxy, but typically mixing resin types doesn't gain much of an advantage, and can be a disadvantage.
     
    Last edited: Jun 1, 2022
    fallguy likes this.
  8. Jim beam
    Joined: Jun 2022
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    Location: Africa

    Jim beam Junior Member

    Hi ondarvr,

    I first laminated the tanks in 2002. Since then I have seen some blisters form here and there as the tanks are full a lot of the time. The polyester/CSM/topcoat is submersed much of the time. Over 20 years it takes its toll. The idea of an epoxy top layer this time is so I dont get blisters again in the future. The layup already has a poly/CSM layup so I have to go over that with another poly/CSM layup to get some build up on it. The final coat will be an epoxy with light cloth to give the epoxy something to hold onto. The epoxy is a REAL waterproof layer. I dont want to do this job again - getting too old for all this. The epoxy (especially from China) is not a whole lot more then the Ortho Poly. Add the transport issues I have with whatever I get and the time and effort involved...I would rather just pay a little more and finish in a last layer of epoxy.

    Then there is my next project. I am going to try building tanks from EPS and laminate with an epoxy/cloth layup and see how they go. I have read a lot of stuff about EPS/XPS here. I feel that for static water tanks that will never be moved EPS with epoxy can work. Why this approach? I want two things - weight reduction in the tank itself and insulation - even here in the tropics it can get chilly at night. I've seen the water temps drop from 26c to 23c overnight. I want to reduce that delta a bit if I can.

    Back to the Chinese epoxy. I will try to get a data sheet today. The epoxy in China is about $6USD per litre less expensive then the South African stuff. I dare not even price West Systems in South Africa for fear of the fright I will get. The South African epoxy comes from local South African manufacturers - some of whom are makers of flooring epoxy - had a long conversation with the chemist who makes the formulations - he told me they import the part A as everyone else does and they blend thier own hardener. So it sounds like the only difference is in the hardener. But that's quite the difference though.
     
  9. Jim beam
    Joined: Jun 2022
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    Location: Africa

    Jim beam Junior Member

    I will look into that and see if I can get a sample out to me somehow and just try it and at the same time try a sample from South Africa. Put them side by side to see how they wet out, the viscosity , pot life etc.

    The South African epoxy manufacturers are making epoxy for flooring mainly. So not your typical US composites or Total boat or MAS epoxy - more of an industrial epoxy. So I wonder how big a difference there is between the local South African brews and the Chinese stuff? At least the Chinese have a hand layup version for marine use that sounds like its down the same road as the American marine epoxies.... I dont know though. There may be little difference in epoxies when its all said and done.
     
  10. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    I know a fellow in West Africa who used industrial epoxy for his boat and it was a total catastrophe. He built the thing and thought it okay, but totally delaminated for him. He got lucky. He only used thr industrial crap on the inside.

    If I remember correctly; it was too thick and never wetout the glass correctly. Be very careful to get datasheets on these and compare.
     
  11. Jim beam
    Joined: Jun 2022
    Posts: 13
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    Location: Africa

    Jim beam Junior Member

    Yep
    Yep - good info and advice right there. Thank you.

    What sort of CPS should I be looking for with regards to a hand layup laminating epoxy ?
     
  12. Jim beam
    Joined: Jun 2022
    Posts: 13
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    Location: Africa

    Jim beam Junior Member

    Also, what sort of shelf life should I expect if stored in dry cool place - say 20c ?
     
  13. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Use conventional epoxies for baselines. You must do full comparisons of the datasheets. I have gotten so used to System Three Silvertip that I use nothing else, but Ampreg resins are another high quality, well tested resin.

    Another thing to consider is your environment. Epoxy shelfs well at 20-25F. It tends to separate under freezing temps. Hardeners dry up uncovered. But stuff last for years with minimal care. However, if your work area is hot, you may need to switch to tropical resins with 2 hour gel times. Epoxy does not do well in direct sun. Because the reaction is exothermic, the sun speeds the gel times and the variarion is impossible to pin down; so it is just not done.
     
  14. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    Ok, I understand your desire for epoxy.

    The polyester must not be a very good one, most marine versions don't have a problem with being submerged like that.

    Since you aren't really looking for this Chinese epoxy to be a structural component, just a barrier, it will probably be fine, even the most basic epoxies can handle this type of job.

    Working with it may be a bit different, but again, you aren't doing much with it, in a thin laminate you can work around most anything.
     

  15. Jim beam
    Joined: Jun 2022
    Posts: 13
    Likes: 1, Points: 3
    Location: Africa

    Jim beam Junior Member

    Edited this. After posting things started moving a bit.

    However the question remains - does anyone have any other Chinese epoxy manufactures that they can either recommend or at the least know of ? I would prefer to source from a company doing composites rather then just an industrial epoxy maker (which I would'nt do).

    What other Chinese composite companies are out there?
     
    Last edited: Jun 7, 2022
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