I used the "Rot Doctor" CPES epoxy to help stabilize an antique pistol stock. I drilled several 1/16" holes in hidden areas and used a large veteranary syringe to inject the stuff into every area possible. It's about the consistency of diesel fuel and really wicks into the end grain. Get the warm weather formula, mix more than you think the stock will take, and expect to spend 4-6 hours with the stock making sure it absorbs as much as it can. The cans say the epoxy will begin to kick within 8 hrs or so at room temperature... that's about right, but it will remain liquid in your mixing cup for several days or weeks. I didn't get full strength until at least 2 weeks later, but now that it's fully cured the wood is very tough.
I also injected it into a couple soft areas of plywood on the boat (that I didn't have time to replace this year). I didn't think it'd do much, but the area is surprisingly stiff now. Hope this helps!
-Eric