Polyester ? Vinilester ? Epoxy ? Which resin ? what is the best solution ?

Epoxy = Strongest, best with UV stabilizer

From an engineering standpoint any high performance composite uses epoxy.

If i say wrong please correct me ; vinlyester is flexible than epoxi .
So professional kiteboard makers use which one ?

in general,
you will find that epoxy will produce stronger laminates than polyester or vinylester.
longer working time during cure is more convenient for bagging
low volatile content means less of a respiration hazard
some folks are overly sensitive to skin contact. (nasty rashes if you dont wear gloves)
poor uv resistance w/o additives or paint
more expensive.
better chemical compatibility with most cores ( wont eat styrene)

polyester is cheaper ( commonly used for surfboards and boats)
eats polystyrene
high volatile content (needs lots of ventilation and a mask)
it stinks and can give you a nasty headache
quick cure times
brittle compared to epoxy
good uv resistance (nice clear coats for graphics)
works well with urethane blanks (eats styrene)

vinlyester, as the name suggests, is a close relative to polyester for virtually all of its properties
a bit stronger and tougher than polyester; and a more expensive.
vinylester also has better moisture resistance when cured ( compared with polyester) but i've heard that it is more sensitive to atmospheric moisture during the cure phase.
its low viscosity is a plus for wet out and vacuum infusion projects
i dont believe either is known for their flexibility when compared to epoxy

-bill


If i was starting from scratch, the convenience of epoxy justifies the expense for me.
its easier to mix only what i need, and mix more later if necessary ..so less waste.

however, for a first time project:
if i had a gallon of polyester laying around i would not hesitate to use it ( outside with gloves)
its still a fast way to make a good hand layup.

zfennell ;
thanks lot.

If it was me I'd use epoxy (as I have making my surfboards) and spray it with a UV polyurethan spray can. As zf points out ester based resins case cause styrene attack on cores and that includes corecell dyvinicell herex ePS............ if that happens you can pretty much throw it out.

I also find that epoxy mixed by weight is the easiest way to mix any resin. You can also get different speed hardeners for epoxy which can give you cure times (temprature dependant) anywhere from 30 min to 5 hours.

Not sure where your located but as far as finding materials in OZ there's FGI, Summit (WA), Gurit (they might send you to a disributer) that sell core, bagging supplies, material, resin they can also give you helpfull tips on their products on what might work for what your trying to achive.