This sting of poor rivets

Well, I have gone and done it. Totally ruined my left aileron trying to rivet the skin to the main spar. What an awful area to try and rivet. The spar flange has a slight acute angle to it which presents a bit if a challenge to get the bucking bar at an angle to help sit flush with the rivets. I used just about every method I could think of to try and rivet these properly. I used a small oak shim in an attempt to prop up, or adjust the tungsten bucking bar to the appropriate angle. I've tried different bucking bars, different angles, different shims, taking angry, talking pleasant, massaging it, giving it a break, everything!!!! and in the end, every rivet shop head wants to dump to the same side every time. Of course once a dimpled rivet hole has been dumped now the nightmare begins. Will it dump again, well chances of it going awry are growing. Too many times, now an opps rivet. ****! the oops rivet has dumped...They all dump in the same direction. After about 3 hours if consistently terrible rivets all dumped the same direction I have successfully ruined a potentially perfect aileron.

Just a sampling of how ALL of the rivets wanted to set...



Today....building my plane has not brought joy to my life!!

Shop heads

Bummer. Sorry you had a bad day.
I would suggest a method ut it sound like you tried them all including the one I used. I used a shimmed tungsten bar. I learned the perfect shim always seems to be more angle than looks right. Practice on that one till you find a method that works for the next one.

Is that a shadow (gap) between the parts?

Thanks Wirejock. The tough part is I can for the life of me figure out why they were doing this. I'm really worried I will mess it up again if I order another aileron. The right aileron gave a me bit of trouble but it worked out alright. But the left....it was just a runaway train. The angled portion of the bucking bar was perpendicular with the rivet head. Should have set straight. I even tried holding the bar in my fingers without any guide. Same result. Maybe there was some sort of side load on the rivet when setting them. Maybe the three skins/spar where slightly out of alignment.

Looking at my parts graveyard....I think I see enough parts for three planes!

Here's how I solved the problem on my RV-3B ailerons.

On mine, the spar flange to skin was difficult. This C-shaped tool and a handy box end wrench did the job nicely.

Dave

Whoa David!!! Million thanks to you!!! You have been there too and solved it. (I see you ruined an aileron too...guess I shouldn't feel too bad as this is a tough one to rivet).

I guess that answers how to avoid screwing up another aileron!

No idea if this will work for you; everybody's different. But IIRC, I had more luck in those situations by ignoring the side structure & 'calibrating' my fingertips/thumb tip to feel for the bar's surface being parallel to the flange/skin. I also 'cheat' with neoprene or rubber sheet that's roughly the same thickness (better if slightly thicker) as the unset rivet tail length. A square or disc with a #40 hole drilled in it will hold the rivet in place, help keep the bar parallel to the flange, and help clinch the skin/structure together. Once the rivet is partially set, you can go to a thinner sheet, or trust your calibrated fingertips.

To re-square the dimples, have you used the trick of putting the male die in a rivet set die-holder, and a shop-made female 'die' drilled/countersunk into a bucking bar? Line everything up, and give it a *light* tap or 3 with the gun. Obviously, everything needs to be lined up for this to work.

FWIW,

Charlie

I recall making a lot of rivets like that.

I think what helps me - basics

- make sure the rivets fit the hole well, not loose, and not sticking up on the manufactured head. Only touch up the hole if the rivet won't go into position with a good push. If a rivet feels too loose or too tight in a hole - try another - there are variances in the manufacture of these things.

-if the mfg head is not sitting nicely in the dimple or countersink, touch the dimple up with your countersink bit - very lightly to make it lay in snug.

- use rivet tape even if you don't need it to keep the rivet from falling out

- I like to use LOTS of clecos. Every other hole at least on most parts. Some parts I cleco every hole and only pull the ones where I am riveting.

- I like to start driving with a very short burst to set the rivet snug in the hole, and follow with a longer brrrrt.

- if at all possible, clamp your piece down to keep it from moving too much.


I think these set up items are probably more important than the angle of the bucking bar.

David Paule said:

Here's how I solved the problem on my RV-3B ailerons.

On mine, the spar flange to skin was difficult. This C-shaped tool and a handy box end wrench did the job nicely.

Dave

Click to expand...

Worth mentioning is that I visited my mentor's shop not long ago, considerably after I'd done this, and on a wall he had a number of different-sized C devices like this that he'd made for his project.

Dave

Wish we had a Yard Store in Canada. To get a C-Frame Rivet set up here is gonna cost me about $60

If you can weld, weld one up from thick scrap.

Dave

try and find a post by cytoxin or captain john

I did a terrible job on my rv-4 and really searched the old posts and one of these guys had a post with pictures and the bar to use and after following this post the ailerons were easy the post have to be about 8 years old by now. the jest of the post was to build a jig so the aileron was vertical and then be able to put one arm under the aileron with the bar and go through the hole with foam holding the skins apart the bar was a small tungsten bar that fit in the web of the spar but I used one that was longer then the spar web but with an angle that matched the web had a piece of leather under the bar to raise it and not mark the spar

Sorry to hear your frustration.
Another solution that worked for me was to tape a #40 drill bit along the long(fat) edge of the tungsten bucking bar. This brings the long(narrow) face to the same angle as the flange. Then just slide it along the web.
Cheers