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iwannarv

Well Known Member
When riveting universal head rivets, many seem to be developing a 'lip' or edge on mainly one side of the rivet. This may happen every 1 out of 4-5 rivets. I'm sure that the structural strength is just fine (heads are still round), but when I, the picky builder, look at them in person, they look horrible. I may also be trying to be too much of a perfectionist.

Here is a picture of a good rivet next to one of my troubled ones (RV3 HS Spar):

DSC00652.jpg


I don't like frequency that this is occurring, and I assume that I need to bump up my gun pressure (2x at 40-45 psi, 1/8" rivets) to drive them a bit faster. The driven ends check fine with a gauge and are uniform.

Looking for a peace of mind that I am becoming too anal-retentive and just need to shoot some primer on them so I stop looking and just build the thing... (but please, your honest opinion on the rivets)
 
A 2x gun at 45 PSI does seem light for 1/8" rivets; I use 75 PSI for my 3x gun when driving them.
 
Snap Soc

I start at about 55-60 psi and go up as the rivets get longer. Try a higher pressure, should help a bit. I don't think either of those rivets need to replaced unless its for cosmetic reasons.

Also, get some Snap Socs from Avery tool. They are great and are well worth the money if you want to maintain the appearance of the factory head.
http://www.averytools.com/p-884-snap-socrivet-set-caps.aspx

Eric
RV-7
FWF/Cowl
 
Sometimes a bad rivet set can cause that problem. Sometimes, it's the user. ;-)

I inherited a universal rivet set that didn't have a deep enough dish on the driving surface. It caused defects that looked like what you have. I eventually replaced it and the new set (probably from Avery or Cleveland) which didn't cause the same problem.

Later, just to see if it was a skill/technique thing or an equipment issue, I drove a bunch of practice rivets with the old and new sets. The old set still made smilies, whereas the new one never did.
 
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They're OK, what's happening is the rivet set is bouncing on the rivet. Try placing a piece of masking tape on the head before riveting. I was amazed how much better the heads endured the process. I have a 3x gun and for universal -4 I ran about 55 psi More air pressure makes faster hits only means you'll smile that rivet head faster:) It's all technique, looks like you doing good, the tape will help.
 
Actually, both rivets in your photo show a related problem. The one on the right has an indentation on the rivet head, as you described. The one on the left has an indentation in the spar itself, right next to the rivet. Both are likely the result of you not keeping the set lined up properly (centered and straight) on the rivet, or letting the set bounce around while riveting.

iwannarv said:
Here is a picture of a good rivet next to one of my troubled ones (RV3 HS Spar):

DSC00652.jpg
Click to expand...
 
masking tape

They're OK, what's happening is the rivet set is bouncing on the rivet. Try placing a piece of masking tape on the head before riveting. I was amazed how much better the heads endured the process. I have a 3x gun and for universal -4 I ran about 55 psi More air pressure makes faster hits only means you'll smile that rivet head faster It's all technique, looks like you doing good, the tape will help.
Click to expand...

I used masking tape as well, but on the gun rather than the rivet head. Putting a small piece of masking tape over/in the cup on the rivet set helped eliminate this for me. Had to replace it relatively often as it wears through, but it worked for me.
I generally used about 45-50 psi (at the compressor, using 50' hose) with 3x gun.
 
My thoughts.

I have seen this and done this also.

When you press the rivet set on the universal head rivet and press down, the pressure might not be fully in line with the rivet.

This may happen even if all is square. A regular rivet gun has the barrel and the handle.If you put excessive pressure on the handle farther away from the barrel it will cause a swiping action at the end of the set relative to your starting position. If its real bad you will get a series of smiley faces across your skin, if this is just barely happening it will look like the rivet your concerned with.

The trick is to not put excessive force but let the pneumatic rivet gun do the work while you keep it in the correct position.

If you think 1/8" rivets are bad at this the 3/32 universal heads can be worse. Fortunately you dont have them on the Vans models.

Best wishes!
 
So should I go ahead and drill out the affected rivets, or is this not much an issue of quality of strength, just purely cosmetic?
 
Mmmm....

iwannarv said:
So should I go ahead and drill out the affected rivets, or is this not much an issue of quality of strength, just purely cosmetic?
Click to expand...

If there is no space under the factory head, and the buck tail looks right, it should be structurally sound.

If you do drill them out, use a #30 drill and don't drill deep enough to go into the skin level. Put a 1/8" punch in the hole and crack the head off.

You can then pop the tail out with an automatic center punch, or a regualr punch and a small ballpeen hammer.

Caution, you will probably need to support the aluminum on the tail side so it does not get distorted when you drive the old rivet out.

Best wishes,
 
  1. Different rivet guns need different amounts of air pressure, so don't put pay too much attention to air pressures quoted by other folks. Also, the amount of air pressure you need will be higher when riveting stiff areas of structure. Learn what air pressure you gun needs.
  2. Up here in Canada, hockey shin pad tape works very well on the rivet set. It is a thick, flexible tape. It provides a bit of a cushion to keep the rivet set from marring the rivet head, and it helps keep the set from bouncing off the head.
  3. The rivet head in that picture looks structurally sound. There is no need to drill it out and redo it.
 
You do NOT need to drill out the rivets. They are ugly, not structurally deficient.

If you wanted you could polish the heads smooth, or prime/paint over them.
 
Thanks for the responses, I think that my main problem was putting excessive force on the gun to keep it from bouncing off the rivet, causing it to move off-center. I may try to drill out the real bad rivets (like pictured), but leave the ones that are barely noticeable the way they are. If I have too many doubts, I can move on to a different part and re-do the HS Spar. I won't be the first....
 
iwannarv said:
I may try to drill out the real bad rivets (like pictured),
Click to expand...
Those are not real bad. I know what real bad looks like :eek:
Just leave them alone, they're fine, and it's likely you will end up with a weaker rivet if you drill them out and replace them. Re-read Van's instructions about if one should replace "bad" rivets and the strength testing done with good and bad rivets.
 
I ran into this problem some time ago and believe I solved it (at least for me anyway). Holding the rivet gun by its handle and pushing down with the handle is a natural thing to do. I found that by putting the palm of ypur other hand on the back of the gun and pushing in line with its hammering action the problem disappeared. The pervious poster is correct in that by having a pushing force (using the handle) not directly in line with the rivet causes this problem. If you look at some of the more powerful rivet guns their handles are shaped in a loop so that when pushing on the handle the force is in direct algnment with the rivet.
In its extreem case you can actually smear the rivet head in the direction opposite to the misaligned force (ask me how I know).
Val K.
RV-8
Dayton, Oh
 
Waco01 said:
I ran into this problem some time ago and believe I solved it (at least for me anyway). Holding the rivet gun by its handle and pushing down with the handle is a natural thing to do. I found that by putting the palm of ypur other hand on the back of the gun and pushing in line with its hammering action the problem disappeared. The pervious poster is correct in that by having a pushing force (using the handle) not directly in line with the rivet causes this problem. If you look at some of the more powerful rivet guns their handles are shaped in a loop so that when pushing on the handle the force is in direct algnment with the rivet.
Click to expand...

I wish someone had taught me this when I first learning...it *does* work better (but requires you to hit the trigger with the middle or even third finger, so I have yet to feel comfortable with it in cases where it really matters and a ding or smiley on the part will be visible or critical). It's unnatural feeling at first, but I think with a little practice, it's probably the best way to go...

Masking tape or even duct tape on the rivet set works wonders, too...

"Smeared" rivets...yeah, ask me how I know about those :)
 
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