blind rivet sizes

[prkaye]

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?

[Paul Eastham]

Hi Phil,
I do not believe any such table exists, because each solid and blind rivet type have different strengths, and spacing varies -- the number of combinations would be huge.

Have you read the riveting mil-spec and the part of the RV manual about riveting? Van's says that "smileys" on the factory head are generally ok. My reading of the mil-spec is that a cleated rivet might be ok if you can't see the underlying hole and the usual head size requirements are met.
http://rvimg.com/MIL-R-47196A_MI.pdf

You are defintely correct that replacing rivets can make things worse, especially when thin layers are involved.

Even if you do have unacceptable rivets, they may be better left alone.
Van's often allows substitution of cheezy LP4-3 blind rivets on some rib flanges -- your flawed solid rivets may be stronger. I recommend that you send a picture to Van's showing them which and how many rivets you don't like -- they may tell you to leave it alone.

[prkaye]

Thanks Paul!

cheezy LP4-3

Why are they cheezy?

I've decided to invest in a longeron yoke... I've always had waaay better success with squeezed rivets (pneum. squeezer), and I have been dreading doing the ribs to rear spar rivets (near the floor) the old fashioned way. Longeron yoke should make those a snap.