What’s a ‘dink, dink’ rig?
This is a blockend feeder set-up that you don’t see used much these days, but when river fish are active it can be brilliant especially with dace and small chub. A standard ‘dink dink’ set-up has the feeder at the end of the line and one or more short paternoster hooklengths (only around six inches long) coming off the mainline above. It’s effectively a bolt rig, the fish hooking themselves against the weight of the feeder as they dart around grabbing food.
However, there's no reason to assume that the word 'dink' is used with the same meaning in both sentences. It's a word that has dozens of possible uses . In the klink and dink method of fishing, the beaded nymph (dink) is actually attached to the hook bend of the emerger or dry fly (klink) ; so we can make sense of sentence 1. Then , dink can also be used in ways indicating light contact - as a noun, =dent, or (vb) we can dink a ball over the net, etc. ; so in sentence 2 we can give it the natural sense Garoubet suggests above.Pas facile; si on regarde la deuxième occurence de dink dans le texte, on pourrait comprendre comme: de cette façon, la pointe ne peut pas s'accrocher/frotter sur le "couvercle" et s'émousser.
Par contre, ça n'aide pas vraiment pour la première phrase.