Time for a little bit of basic wood/epoxy technology. Your paddle's tip is end grain. If you expect the paddle to last and you are applying an epoxy tip, you had better hope the resin wicks up into the wood - just as far as it can go -because if it doesn't, water eventually will! I don't think I need to tell you all what that leads to.
If you are using a filler that makes the resin so thick that it doesn't wick well up into the end grain, then it's not doing a proper job of sealing out water (or bonding) and you're just asking for trouble. Wood/epoxy technology does not revolve around the principle of "sort of" sealing the wood to prevent water intrusion, it relies on doing everything possible to completely seal the wood.
Thick hunks of resin and/or resin containing tints or pigments look nice, but are quite brittle if they happen to be attached to something that occasionally gets bounced off of rocks. In order to temper that brittleness and drastically increase durability, you can mix the resin with a high amount of various types of filler particles or fibers. These will thicken the mixture and as mentioned, reduce penetration into the wood. In the process, you greatly reduce both the strength of the bond between the wood and the resin tip and the amount that the resin can seal the end of the raw wood.
The way to take advantage of the strength and durability boost offered by the filler/fiber mix and to still get maximum sealing power (and without wicking colored resin up into the wood) is to pre-coat the wood in the bonding area with several coats of unfilled, unpigmented epoxy. Mix some resin and hardener together and brush a coat on the raw tip wood. Give it a few minutes and do it again, if that seems to soak in and disappear, do it again. You should see the resin absorption stop or slow to a crawl before you ever even think twice about moving on to adding filler or pigments and forming the tip.
Whenever you are bonding epoxy resin to wood the absolute last thing you want to do is anything that will reduce the epoxy's ability to penetrate, seal and get a really good, deep grip on the wood. This is why any spot where you use heavily-thickened, filled resin on a boat should always be well coated first with unthickened resin. If it's thin, it flows in...if it's thick it won't stick.
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