The ratios aren't that tight. Anyone that can't perform a 2:1 mix probably shouldn't be messing with the stuff in the first place. I think people mess up the mix thinking they can push the resin kick by adding hardener like polyester resin and MEK.
When I'm making or repairing something, I do multiple laminations at one time and cannot for the life of me see the value in waiting hours for the resin to kick.
Life is just too short to waste waiting on bad epoxy!
you are correct in everything here....
but for some people reading this who may be thinking its not at least a little bit important to be as close as possible, or that their untrained eye will get them thru a first time project without a glitch, I will add this....
epoxy and polyester resin and it's hardener are way different than epoxy resin and it's hardener even though the workability is almost identical.
study the properties of each to make the correct long term decision on which is best for your project.
even though the ratios arent that tight for the epoxy to cure and be workable (or polyester resin for that matter) a bit too much one way can shorten the perfect life of the finished product. I will refer to gelcoats which are NOT epoxy, but where after a while you get the crazing lines and actual cracking of it, letting water in to do more damage over time.... a perfect mix wont do this in its normal life....
and to far out of ratio the other way, the finished product will never reach its intended strength. some projects dont require such critical attention, but then some do....
and some of us can mix fairly close without a scale, but its also surprising how far off we can be sometimes even when we think its perfect. specially in a small batch. with a scale you can have it absolute every time. I also think its faster, and there is no bit of extra product left in one bottle when the other is gone....
I dont like unecessary waiting either when its the only project on the bench at the time and have notheing else to turn my attention to while waiting
so its good to have a couple different hardeners on hand so you can mix either a fast cure or a slow cure, (as well as a thickening agent) depending on your need for the project, and for the first coat on any wood I firmly believe in and recommend a thin resin with a slow cure hardner. it will be the foundation coat and its good for it to stay in its liquid state so it can penetrate as deeply into the wood as possible. a good strong foundation is worth waiting for, no matter what the project is...
when coating over an already sealed, firm surface, the fast cure may be the perfect mix if its a reasonably small project, or you are prepared to move fast...
