Epoxy in general does pretty well around water. I've even heard of epoxy paint that was applied underwater to pier pilings to discourage barnacles.
The trick to getting epoxy to stand up to wetting is more a matter of surface preparation than anything else. Surfaces collect invisible contamination and corrosion that must be removed before you apply your epoxy. For metal surfaces the best you can do is to wipe with clean acetone and etch with a powerful acid solution. For aluminum aircraft structures we used to use a mixture of sulfuric acid and sodium dichromate. I don't know the optimum etch for stainless and you probably don't have it handy.
Instead of etching the bonding surface you can mechanically strip the surface using abrasives. You are not "roughing the surface up" as some describe it, you are removing the old surface to expose new material. A little roughing of the surface is OK, but that is not the goal. You want freshly exposed metal molecules that are not cross-tied to each other or to some molecules they got from the air or your fingers. The most common surface contaminant is actually water from the air. A good way to mechanically clean the surface is with new, clean, wet or dry sandpaper. Then wipe off with clean cloth. Within a few hours of this cleaning you need to apply your epoxy or you should repeat the cleaning.
You can probably use the same cleaning technique for the G-10.
If you don't do this preperation your epoxy won't be as intimately bonded to the underlying surfaces. Water is a very powerful wetting agent that will find ways to bond to surfaces of your knife. It will slowly diffuse across the bonding surface and displace your adhesive connection to the surfaces. This monomolecular wetting process is a classic way for bonded surfaces to fail.
As far as what type of epoxy, I'm a little out of touch. I used to use Dexter Hysol industrial epoxy, years ago. Pick a major brand. Avoid the quick drying epoxys, they aren't as good or strong. You want something that has about a one-hour working period. Typically it has an 8 to 24 hour curing period. You should cure the epoxy at a slightly elevated temperature. You don't want it too hot or you will bond in stresses due to uneven thermal expansion of your handle and blade materials. The epoxy will be strongest, and the bond most effective, if you use somewhat elevated temperature. You will also get quicker curing. You might use a 100 watt light bulb in a desk lamp to elevate temperatures by about 10 or 20 degrees. You want it over 100 degrees fahrenheit (40 C).
