Rod Bond tolerates mis-matched hardner and epoxy ratio very well if not over done. Get two sets of steel measuring spoons at tha Dollar store or someplace similar. Use one set for epoxy and and the other set for the hardner. They will also work well for Flex Coat.

If you are going to error on mixing, error on the side of a little less hardner than epoxy. Your Rod Bond should set to a pretty hard glob that you can leave an impression in it with a a finger nail.

It is a very good product. I have used it for years with never a problem.

Good luck with your project,

fishbum