You do not have a HUGE MESS, You have a 24 hour delay.
If you show up at your project and discover that you forgot to mix in the hardener, simply mix another
batch of resin with the proper amount of hardener and reapply over the unmixed resin as per original
instructions. Return in 24 hours and all is well.
Try it with some scrap, it works. Learned this trick years ago while working with Polyester.
That may work with polyester, but epoxy cures differently. It needs the correct amount of both parts to cure, as opposed to polyester, which only needs a catalyst to start the curing reaction. If you glaze over an improperly-mixed epoxy with properly-mixed epoxy, the exterior surface may appear to cure, but the original layer of epoxy will still lack the reagents it needs to fully cure and crosslink. Depending on how bad the original mix ratio is, the layer of resin in direct contact with the fiberglass and the surface of the wood could still remain tacky and soft, reducing or eliminating its structural benefit.