Flush Riveting Skins

Hello all,

As I wrap up (almost literally) my HS and VS I've come here to get tips and tricks for riveting the skins to the sub assemblies. I do fine with most of the other riveting but when it comes to using the bar and gun for flush riveting. Let's face the facts I suck at it. As of now anyways. Like I said I do alright with the universal rivets but for some reason a majority of my flush riveting isn't too pretty. Before I really screw up a skin id like to get everyone's best advice and plow through a pile of scrap before finishing.

Thanks,
Tim

I have found when riveting to set the gun up on a piece of wood so that it doesn't jump, just sits where you put it. I have a valve control just behind the gun on the air hose. Experiment with the pressure to have the gun doing the job but not bucking uncontrollably, this is how dings usually happen. When actually bucking the rivets don't push too hard on the gun, a gentle touch. Have the bucking bar firmly on the rivet with just enough force to set it. Practise on scrap, I bought some Al from a local hardware and used that for practice. You can use the dreaded blue plastic on the flush rivet set or masking tape, this stops some bruising on the skins.

I have another useful technique for preventing the old runaway rivet gun issue. When I use the rivet gun, I place my index finger on the trigger, then place my middle finger up high so it actually sits behind the trigger. This lets me use the middle finger to regulate how far back the trigger can go.

Using this technique, I can easily and repeatably perform individual hits with the gun if necessary.

I found that using rivet tape the outside of the rivets look better after riveting. Maybe just me.

Rivet set

Get a swivel mushroom set if you don't have one. The rubber outer ring is optional. I like it. Others remove it. I find it reduces the tendency for the set to walk.
Find a grip that works for you and allows you to control both the gun and trigger the teach your non dominant hand to use it. You have to be able to rivet with either hand. I hold all power tools with my index finger pointed down the barrel like a gun. It helps me keep the tool perpendicular. I push on the gun and use a finger or two of the bucking hand on the other side to push back.
Get a tungsten bucking bar. More mass. Less time beating up rivets.
Some sort of protection helps. Pun intended. I use heavy packing tape. I make several before each session. Fold an end over. Flip it and draw an "+" on the sticky side for a target?

+1 what wirejock said.

Also, practice on something else first.

Dave

There's only one way to get consistently good flush rivets.

Use both hands...requires someone else to buck. A flush die has to be controlled with the second hand.

I've shot hundreds of thousands of rivets, I'd never shoot skins by myself. Of course, on a large airplane, you can't reach all of them yourself, but even when I can, I don't.

When you're shooting fasteners on a very expensive skin, you can't afford damage.

You shouldn't take that chance on your skins either.

You don't suck, you just need to use both hands, one on the trigger, the other on the skin with your thumb & finger controlling the die.

My .02

stinson pilot said:

There's only one way to get consistently good flush rivets.

Use both hands...requires someone else to buck. A flush die has to be controlled with the second hand.

I've shot hundreds of thousands of rivets, I'd never shoot skins by myself. Of course, on a large airplane, you can't reach all of them yourself, but even when I can, I don't.

When you're shooting fasteners on a very expensive skin, you can't afford damage.

You shouldn't take that chance on your skins either.

You don't suck, you just need to use both hands, one on the trigger, the other on the skin with your thumb & finger controlling the die.

My .02

Click to expand...

This is good advice, and true, but......for me it was not very often that I could get help to do this, so.... 95 % of my build was solo.

Riveting Tips

I have been teaching thousands of newbees to rivet at Airventure over the past 10 yrs. Here are my tips:

1. As others have mentioned and I recommend hold the gun such that your index finger is pointing down the barrel and your middle finger is on the trigger. Try to get the web of your hand directly behind the barrel. That will really help stabilize the gun.

2. Make sure your air pressure is right. About 35 psi for the skin rivets using a 3X gun. The device mounted to the bottom of the rivet gun handle is not a pressure valve it is a flow control valve. As others have mentioned, using a flush set (swivel is preferred), shoot into a piece of wood on the bench. Adjust the flow so that the set doesn't wander.

3. I use short bursts (typically 2-3). Start out teasing the trigger and you will be able to tell immediately if the bar is out of position. If your bucking bar isn't on the rivet, there is much less damage done one short burst. Once you get very proficient, you can extend the burst time and reduce the number of bursts.

4. Rivet tape helps reduce wandering.

The thing that helped me the most was to shoot some rivets with an experienced riveter. I learned more in an hour than I could have learned in a month by my self.

I find that using two fingers on the trigger (index/middle) provides the best control, and as others have said, don't just jam the trigger in. Start slow and ramp up the intensity/speed of the hits. Riveting with a partner is definitely easier, too.

+1 for using the middle finger to on the trigger with index pointing down the gun. Much better trigger control and the third (ring) finger goes under the trigger to help control as well.

My flat set doesn't have the rubber around it to reduce walking so I put a layer of masking tape on its face and replace it every hour or so.

Thanks for all the replies and advice! I'll get to work!

Tim

If you're working on a part smaller than a whole fuselage or wing, secure it somehow (clamp, vice, etc.) before riveting. It doesn't matter how many hands you have on the rivet gun if the part walks out from under it.

To me, using two hands on a rivet gun is analogous to using a turn signal; it's always a good idea, but it isn't always necessary. The trick is knowing when it's necessary (for you). I get help if I have to (1)straighten either arm to reach either side of a rivet, (2)can't see the set on the rivet, and (3)any time I use an offset set. I'm sure there are others, but those three come immediately to mind, and all were learned the hard way.