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OK 6min. 12min, 30min, epoxy, are all these minutes necessary?What is the difference? Just learning !
thanks Ron

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If you need to layup something that takes longer than 3-5 minutes... you'll want 10 or 30 minute instead.
There may also be a strength tradeoff in the faster-setting epoxies, but it would probably be negligible
for most applications, as it's always stronger than balsa. I still use nothing but 30-minute on wing joiners, however :)

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I don't even buy anything but 30-minute epoxy

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The longer the cure time of the epoxy, the stronger the joint. This is mostly due to the fact that it has more time to soak into the wood fibers before it sets up. Longer cure times also give you extra working time.

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Faster cure also can heat up tremendously if done in large batches. If you mix up a total of 1 oz 5 min epoxy and let it sit in the container where it was mixed... it will start to fume (smoke) within 1 min. It can start to harden in under 2 min.(because heat speeds the curing) It is possible for it to ignite a styro mixing cup. The fumes can be lethal.

Longer cure time epoxy tends to be thinner. making it easier to avoid applying excess, but making gap filling more difficult.

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Maybe if you inhale these toxic fumes and get sick, you can sue them!:D

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Longer cure times are stronger joints because the Molecules formed are longer and this increases the molecular entaglement.

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But if you had smaller molecules wouldn't there be smaller, but a larger amount of molecular entanglement?

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When you re-kit the plane you have the ultimate molecular entanglement. :D

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lol very true:D

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Funny replies, I got a good chuckle out of those...I've atomized a few kits myself[sm=drowning.gif] For an experiment take some spaghetti noodles and divide into two pans of boiling water. Break one half of the noodles into little pieces,boil the noodles, drain the pans and let sit till dry. See which one makes the harder cake to break apart. Plastics are like that. For instance in a polycarbonate if the molecule were the size of a spaghetti noodle, the molecules would be approximately a mile long.. The more they re-entangle the more they lend each other support ...when processing thermo plastics one must take care not too create too much alignment in the molecules. One technique used is to use a rapid injection speed to line up the molecules and lower the viscosity due to the non-newtonian behavior then slow the injection speed before final fill and pack stages. Five minute epoxy is like the small noodles you made, thirty minute epoxy is more analogous to the unbroken noodles.