I'm doing a little advanced planning. I have an EVA fore grip I'm thinking about using on a surf rod. The I.D. of the grip is 1/2 inch, and the blank where the front of the fore grip will sit appears to be the same size or slightly larger, but probably not by much more than a few hundredths of an inch, while where the rear of the grip will sit is obviously a bit larger. I plan on using Rod Bond to secure the grips and reel seat. Is this grip an acceptable fit or do I need to drop to a grip with a 3/8" I.D. in order to have more compression between the rod and the grip?

It should work no problem. It will slide pretty easy into place and rod bond will keep it there. Just put rod bond above where grip will sit so grip doesn't wipe glue off blank.,It will get under grip before grip touches blank. Once in place strech girp to original length.ED..

In my experience I have noticed that if the grip is only slightly smaller than the blank it will be about the same firmness as it is off the blank. When I have fitted eva grips which had an i.d. quite a bit smaller than the blank, it seemed to firm up the grip once in place. What you have will work and stay there. But if you want it to be a little more firmer I would drop down in i.d size. I don't know if what I just said defies the laws of physics but it does seem to get firmer.

Steve