VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #11  
Old 11-25-2009, 07:05 PM
Walt's Avatar
Walt Walt is online now
 
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 5,687
Default

A clenched rivet is offset or bent over, if you can fit a .002 feeler gauge between the pieces and touch the shank than you have a "shanked" rivet. Some good ways to prevent these have already been given. Here's a link to the spec sheet:
http://www.vansaircraft.com/public/Specs.htm
__________________
Walt Aronow, DFW, TX (52F)

EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 1700+ hrs, New Titan IO-370, Bendix Mags
Website: ExpAircraft.com, Email: walt@expaircraft.com, Cell: 972-746-5154
Reply With Quote
  #12  
Old 11-25-2009, 10:40 PM
rv72004 rv72004 is offline
 
Join Date: Nov 2005
Posts: 452
Default

Quote:
Originally Posted by Denase View Post
We used to use a thick piece of rubber with a hole punched in it to go over the rivet. We would start to "shoot" the rivet then remove the rubber and complete the shooting. This would draw the two pieces of aluminum very tightly together before the rivet swells as a result of shooting.
Out of interest, what kind of thickness did you find works best. I suppose this will be also a function of how compressible the rubber is ?
__________________
EJ
RV7 flying
xp360, CS, All Glass cockpit
Reply With Quote
  #13  
Old 11-26-2009, 06:03 AM
apkp777's Avatar
apkp777 apkp777 is offline
 
Join Date: Oct 2008
Location: Schaumburg, IL
Posts: 2,053
Default

Welcome to the world of sheetmetal.

Lot's of good suggestions on how to help this. To be honest, when working with thin sheet (<.032) you are gonna get gaps and shanked rivets. (rivet set so that you can reach it with a feeler gauge between sheets). Back riveting helps, driving the head on the "thinnest side" also you can use a "draw" technique.

To "draw" takes some real finesse and you use low air pressure.

1. Drive the rivet just a little bit (till it is just barely swollen)
2. Place your bar next to the rivet shank and tap until the gap closes up.
3. Drive it the rest of the way.
__________________
Tony Phillips
N524AP, RV 9 (tail wheel)
Reply With Quote
  #14  
Old 11-26-2009, 06:13 AM
Denase Denase is offline
 
Join Date: Oct 2009
Location: Colorado
Posts: 40
Default

What thickness I am not sure, I do remember the neoprene being just thick enough to be even with the top of the rivet before shooting. So you would use slightly thinner material for a number three than a number four or five rivet. The donut also worked when we used a phnuematic squeezer. Looking on a website this am I found a company that sells samples of neoprene cheap. Comes in .063, .092, .125, and heavier. There are alot of guides to tell you how high and wide the finished rivet side should be, but not how much rivet shank should be exposed before shooting.
Reply With Quote
  #15  
Old 11-26-2009, 09:16 AM
Denase Denase is offline
 
Join Date: Oct 2009
Location: Colorado
Posts: 40
Default

Just curious. In the early 80's I worked at the old FRONTIER airlines where I was involved with the replacement of entire belly skins, on a 737 due to corrosion. We used the donut technique to drive all the rivets. Has no one else on this forum heard of this?
Reply With Quote
  #16  
Old 11-26-2009, 10:29 AM
minute2 minute2 is offline
 
Join Date: Mar 2007
Location: Beaverton, OR
Posts: 49
Default Use RC airplane fuel line

I use RC airplane fuel line for my "donuts" I think I got this idea from someones build page. I slice off a bunch of these "cushions" from a length of fuel line at a time, as the riveting with destroy a cushion after a dozen rivets or so. I cut the cushion slightly longer than the rivet tail so that the bucking bar will compress the cushion enough to touch the tail of the rivet without requiring excessive force on the bucking bar. If I am having a problem getting the flange to lay flat on its mating surface I will cut a longer cushion. I usually just drive the rivet in one shot and then remove the cushion. I have used this cushion technique on every one of my rivet gun driven rivets except for the fuel tanks. This works pretty good, but after reading others posts on this subject I am going to try the sheet of neoprene technique and see if that works better for drawing flanges tight.
__________________
RV-8A: Flipped fuselage, working on wiring.
Reply With Quote
  #17  
Old 11-26-2009, 10:46 AM
dhammer's Avatar
dhammer dhammer is offline
 
Join Date: Nov 2007
Location: Keller, TX
Posts: 151
Default Old trick

Hit the rivet a couple of taps to start it to swell. Then lay the bar next to the swollen tail and against the sheet and tap it a couple of more times lightly (very). This will bring the two sheets together. Because the rivet is swelled, everything will stay together when you go back finish driving the rivet. I was tought this in A&P school in 1970 and have used it ever since. Much faster that messing with donuts etc.
Reply With Quote
  #18  
Old 11-26-2009, 10:50 AM
Denase Denase is offline
 
Join Date: Oct 2009
Location: Colorado
Posts: 40
Default

Yea I earned my A&P in 1979. The neoprene works much better and faster.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 08:14 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.