|
-
POSTING RULES

-
Donate yearly (please).
-
Advertise in here!
-
Today's Posts
|
Insert Pics
|

11-10-2017, 02:53 PM
|
|
|
|
Join Date: Dec 2009
Location: Montreal
Posts: 1,456
|
|
my -4 rivets all had an indentation around the periphery of the rivet head. I bought new sets - same @#$% thing. I tried different pressures, couldn't figure out the problem. Since the ring was symmetrical, I knew I was straight on the rivet. I tried pressing harder on the bar vs the gun and vice versa. What solved it for me finally was using a heavier bucking bar. The one I used for the -3 rivets just wasn't cutting it. So you could try that.
__________________
Scott Black
Old school simple VFR RV 4, O-320, wood prop, MGL iEfis Lite
VAF dues 2020
Instagram @sblack2154
|

11-10-2017, 06:00 PM
|
 |
|
|
Join Date: Jan 2010
Location: Delta BC
Posts: 122
|
|
For -4 rivets I run 60psi, and that bucks pretty quick. Can take a bit longer in thicker material, so sometimes Ill bump the pressure up a bit.
As for the factory heads getting marked up, put a layer or two of masking tape over the end of the set. A structures guy I worked with once went as far as putting prop tape over the end. The biggest killer for me was side force on the gun, once I got used to straight down pressure it almost does away with the need for tape.
Maybe it'll help maybe it wont!
Good luck
Alex
__________________
Alex Doughty
Canadian ATPL
Flying!!
|

11-11-2017, 10:23 AM
|
|
|
|
Join Date: Nov 2014
Location: Portland OR
Posts: 16
|
|
Aged rivets?
|

11-11-2017, 10:31 AM
|
|
|
|
Join Date: Aug 2015
Location: Leesburg, VA
Posts: 492
|
|
My guess is the brass regulator is reducing the volume of air and making the rivet gun anemic, you are getting perhaps good pressure but no volume. Remove it as someone else suggested and set air pressure in the 50-60psi range and give it a go.
|

11-11-2017, 04:41 PM
|
 |
|
|
Join Date: Aug 2014
Location: Bowie MD
Posts: 886
|
|
Restrictor? Get rid of that. I run my ATS Pro 3x wide open at 100-120 psi at the compressor on 3/8" 100' line, 80psi for -3AD rivets. Tungsten bar for 99.999% of my rivets. 2 flicks of the trigger for -3 and 2-3 for the -4s, usually 3. Sets my rivets like butter.
Yes I run my gun hotter than anyone else. But it works for me and for the people Ive taught to drive rivets on my plane. And I oil the gun regularly.
I dont lean in crazy hard on my gun. Enough to keep it in contact with the metal and slightly more than the bucking bar. For me I also found using painters tape over all rivets (426s and 470s) is da bomb. Cheap, way better than rivet tape in keeping the gun from slipping off mark and if it does, it gives some cushion to that errant hit. I also took the shine off my gun heads with some emery so they have less of a tendency to slip.
__________________
Mani
Busby MustangII (FoldingWing) Pending DAR.
Don't be a hater; I'm a cousin with thin wings! 
N251Y (res)
Last edited by maniago : 11-12-2017 at 06:21 AM.
|

11-11-2017, 07:26 PM
|
 |
|
|
Join Date: Aug 2014
Location: Bowie MD
Posts: 886
|
|
sent you a PM
__________________
Mani
Busby MustangII (FoldingWing) Pending DAR.
Don't be a hater; I'm a cousin with thin wings! 
N251Y (res)
|

11-12-2017, 06:19 AM
|
|
Super Moderator
|
|
Join Date: May 2005
Location: Locust Grove, GA
Posts: 2,626
|
|
As mentioned here before GET RID of tye flow restrictor and use a regulator, just like you would use for a paint gun. Either attach it at the base of the gun, which sometimes makes the gun a little heavier and awkward, or just use the regulator in the line from the compressor.
The problem with the flow reducuer is that on the first few stroke you have ALL of the tank/line pressure available until the flow is enough for the restrictor to actually work. It's way too much, comes out hitting hard, and then slows down, making it really hard to control the gun and the quality of the rivets.
If you want to see a demo so you can better understand it, take your blower attachment or paint gun and attach them first to the flow restrictor, activate the device, and then attach it to a regulated line and activate the device. A picture is worth a thousand words.
Vic
__________________
 Vic Syracuse
Built RV-4, RV-6, 2-RV-10's, RV-7A, RV-8, Prescott Pusher, Kitfox Model II, Kitfox Speedster, Kitfox 7 Super Sport, Just Superstol, DAR, A&P/IA, EAA Tech Counselor/Flight Advisor, CFII-ASMEL/ASES
Kitplanes "Unairworthy" monthly feature
EAA Sport Aviation "Checkpoints" column
EAA Homebuilt Council Chair/member EAA BOD
Author "Pre-Buy Guide for Amateur-Built Aircraft"
www.Baselegaviation.com
|

11-12-2017, 08:26 AM
|
|
|
|
Join Date: Dec 2005
Location: Mahomet, Illinois
Posts: 2,195
|
|
Early on I too struggled with AD4 rivets, despite no problems with 3s. I referred to these very forums waaaaaaay back then, and was told to increase the pressure off my compressor. I goosed it up to 90psi from the previous 50 and that solved the problem completely. Never had a problem after that. 
__________________
Terry Ruprecht
RV-9A Tip-up; IO-320 D2A
S. James cowl/plenum
(Dues paid thru Nov '18)
|

11-12-2017, 09:55 AM
|
 |
|
|
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 9,035
|
|
Another viewpoint......
All of the rivet guns in the shop at Van's have the brass colored flow restricter valves installed (have used them for decades). The line pressure in the shop is kept at max. except for pneumatic rivet pullers.
The brass valve is used to control the guns very precisely. IMO, If a gun won't work with one installed, it is either operator error or a problem with the gun (quality?).
The bigger the rivet, the more sensitive is the technique used.
A one pound bucking bar is too small. Bar pressure is important. The gun/rivet set has to be pushing on the rivet harder than the bar. The bar has to be free to bounce on the rivet.
__________________
Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.
Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
|

11-12-2017, 12:10 PM
|
|
|
|
Join Date: Dec 2009
Location: Montreal
Posts: 1,456
|
|
Aha! So using a bar for a -3 is not going to cut it for a -4.
__________________
Scott Black
Old school simple VFR RV 4, O-320, wood prop, MGL iEfis Lite
VAF dues 2020
Instagram @sblack2154
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -6. The time now is 11:53 PM.
|