When my inspector looked at my emp, he said that it is usually perfectly acceptable to use a blind rivet in places where you have trouble with a hard rivet. He also indicated that, unless you have a whole row of them, badly set rivets are better left-alone (not drilled-out). Does anyone know of a table, or general guidelines to determine equivalencies between blind and hard rivets (i.e. what type of blind to substitute for a given hard rivet).
In my current situation I'm not looking at substituting, but rather at adding extra rivets for reinforcement. For the main wing-spar to ribs, I'm not happy with a few of the AD4-5 rivets on the outboard few ribs. They have had a tendency to cleat, and sometimes the cupped rivet set slips and damages the manufactured heads. If I drill these out, I will probably end-up with elongated holes and a bigger mess. I think a better solution is to add some blind rivets between the hard rivets, in places where I am in doubt. But what type/size?
In my current situation I'm not looking at substituting, but rather at adding extra rivets for reinforcement. For the main wing-spar to ribs, I'm not happy with a few of the AD4-5 rivets on the outboard few ribs. They have had a tendency to cleat, and sometimes the cupped rivet set slips and damages the manufactured heads. If I drill these out, I will probably end-up with elongated holes and a bigger mess. I think a better solution is to add some blind rivets between the hard rivets, in places where I am in doubt. But what type/size?