Composites

    Paint resin on the pieces of cloth and wind them around the milled styroform

  • Cut cloth
  • Just cut. I manually cut it with sewing shears.
    You also can use a lasercutter to do this when you want to cut a complex shape.
    (BUT NEVER CUT PVC(polyvinyl chloride) WITH A LASERCUTTER.)
  • Mix resin and its hardening agent

  • ▲ Polyester resin

  • ▲ Hardening agent
  • I used polyester resin and its hardening agent.
    resin : hardening agent = 100 : 1~2% (maybe by weight, not volume)
  • So I firstly poured the resin until it became 200g then poured the hardening agent until the whole weight (the resin + the hardening agent) became 202g.
  • Causion
    - Do this outside the door.
    - Use a mask which can protect VOC(Volitile Organic Compounds 揮発性有機化合物).
    - Don't use fire near polyester resin.
  • Plus, at this section, I defininetly recommend you to use disposal gloves.
    I used this.
    http://amzn.to/10KZmEY
  • Failure I painted resin on 6 pieces of cloth (aprox. 800mm * 70mm each) but 202g was not enogh.
    I used another 100g resin.
  • Wind pieces of cloth around the milled styroform
  • This part was most difficult in this week.
  • Failure
    - The milled styroform were too thin and weak, one of them was broken and the other one was curved by the weight of resin.
    - The pieces of cloth don't stick to the styroform parts well, which leads to the bad result I describe below.

    Vacuum bagging

  • For bacuum bagging, I used a futon compressing bag instead.
    I bought the cheapest one at the DIY store near my house.
    This one. http://mp.moshimo.com/article/573178
    I used an usual vacuum-cleaner with this.
    Also, a DIY store clerk told me that polyethylene and nylon of which the futon compressing bag is made do not bond to polyester so I didn't use other materials like breather sheet (Should I have used?)
  • I left it for about 24 hours.
    (If you use epoxy instead of polyester, it may be shorter, I guess.)

    Result


  • ▲ The styroform part was originally perfect curve but it was curved by the weight of resin.

  • ▲ left: 2 pieces of cloth on each side(face and back) (the styroform is curved one) / right: 1 piece of cloth on each side (the styroform is broken one)
  • As I described above, when putting them in the futon compressing bag, they were already curved/broken.
    So, of course, they cured with curved/broken.
    Actually I gave up their success halfway, so I tested how hard it become according to the numbers of pieces of cloth put on the styroform part.

    • The first one is not layered. I put one piece of cloth on the face side of the styroform part and one piece on the back side.
    The second one is layered. I put 2 pieces on the face side and 2 pieces on the back side.
    There is a big difference between each hardness. (Of course the layerd one is much harder.)

    Possible Solution

  • - use a mold and sandwich cloth between the styroform part and its mold.
  • - do not use styroform but another harder material
  • - stick the cloth to the part with double-sided tape or glue etc. before painting resin
  • - use smaller pieces of cloth then they may stick to the part better according to the shape of the part.
  • - (maybe) use more powerful vacuum-cleaner or a vacuum pump (I used an usual household vacuum-cleaner, which might be weak for vacuum bagging.)