I've started to get gaps, up to 0.0025, beneath the rivets I'm pulling with a hydraulic/pneumatic riveter (ATD-5850). I've double+triple checked that I'm holding it flush and flat. I took it apart and cleaned it, ran oil through. I tried running it up to 120 PSI, down to 80 and below, no luck.

It's not a burr issue, and my hand riveter is pulling extremely tight.

Any ideas what might be wrong, or what to look for?

Views: 473

Reply to This

Replies to This Discussion

I haven't yet tried a much lower PSI, so I'll try that next.

Not sure if this would cause what your seeing, but are you still using the correct size rivet head for the rivet?  Also, is the rivet head screwed all the way in?

Definitely make sure you have the right rivet head. If you see a little ring in the skin around the rivet you may have been pulling an A4 rivet with an A5 head. Don't ask how I know about that!

Sounds like the gun is starting to fail and is not pulling with enough force-can you switch to another gun at the same psi to confirm?

When I started getting gaps under my rivets I had to order new heads for my gun. If you have the tooling to do it you could resurface the head a bit.
Might be the three stem grabbers are worn inside the gun
Before buying new equipment, think about setting the psi to about 40-45. Aside from having the gun flush, which can easily be off a little, very slowly pull the trigger. When you pull the trigger very slow you can start to feel the rivet slack take up and also often feel the gun seat itself square. A slower pull also allows a little more time for the stem to set. I think that you will an improved result especially if you have also noticed times when the stems are proud of the surface for the same reason.

I'll post an update after I have a chance to pull a handful more rivets (hopefully in the next few days).  I'm going to try a lower PSI and slower pull.

I've also ordered a new head from Zenith since, even if it's not contributing to the problem, it's leaving a nasty ring of dots and nicks around every rivet. Hopefully it will help with this problem too.

Failing both of those, I'm going to see if I can find a way to slow down the internal pull.

Have you tried hand-riveting...?

I hand-riveted my airplane, except for the early parts in the tail section when I was just learning.  Hand riveting does a MUCH better job. 

I tried both the green "toolkit" gun and the blue Harbor Freight one, and I was never happy with the quality of the job done by either of those rivet guns. 

Patrick Hoyt

N63PZ

RSS

New from Zenith:

Zenith Planes For Sale 
 

Classified listing for buying or selling your Zenith building or flying related stuff...

                                                     

Weather Maps


Custom Instrument Panels
for your Zenith
:

Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, power distribution panel, Approach Fast Stack harnesses, Dynon and Garmin avionics, and more.


Custom Upholstery Kits for your Zenith Aircraft:

Zenith Vinyl Upholstery Kits


Zenith Apparel from EAA:


Zenair Floats


Flying On Your Own Wings:
A Complete Guide to Understanding Light Airplane Design, by Chris Heintz


Builder & Pilot Supplies:

How to videos from HomebuiltHELP.com

Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.

Aircraft Insurance:

 
 

West Coast USA:

Transition Training:

Pro Builder Assistance
 

Pro Builder Assistance

Aircraft Spruce & Specialty for all your building and pilot supplies!

© 2019   Created by Zenith.Aero.   Powered by

Badges  |  Report an Issue  |  Terms of Service