VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

  #11  
Old 11-06-2020, 12:52 PM
plehrke's Avatar
plehrke plehrke is offline
 
Join Date: Sep 2006
Location: Defiance, MO
Posts: 1,740
Default

Quote:
Originally Posted by Martyrv6a View Post
Years ago when I started building my -6A, 1998, I used the Matronics Rv-List and I seem to recall there being a posting by somebody using a dental kiln to anneal rivets to make them easier to squeeze or buck. You might try a search on the Rv-List. Marty
Most likely ice box rivets that are 2024 AL not the AD rivets used in the RV. Usually used for large rivets.
__________________
Philip
RV-6A - flying 14+ years, 950+ hours
Based at 1H0 (Creve Coeur)
Paid dues yearly since 2007

Last edited by plehrke : 11-06-2020 at 12:55 PM.
Reply With Quote
  #12  
Old 11-06-2020, 01:14 PM
gasman gasman is online now
 
Join Date: Mar 2007
Location: Sonoma County
Posts: 3,902
Default

Quote:
Originally Posted by Martyrv6a View Post
Years ago when I started building my -6A, 1998, I used the Matronics Rv-List and I seem to recall there being a posting by somebody using a dental kiln to anneal rivets to make them easier to squeeze or buck. You might try a search on the Rv-List. Marty
That was Dave Anders. And he used the AD rivets supplied with the kit.
__________________
VAF #897 Warren Moretti
2020 =VAF= Dues PAID
Reply With Quote
  #13  
Old 11-08-2020, 07:45 PM
vomatic vomatic is offline
 
Join Date: Mar 2008
Location: Iowa
Posts: 20
Default Rivet Age

Years ago when I was building a -4 I spent some time on this topic. Mostly because I wasn't very good at driving rivets and was looking for a easier way. I just dug out my notes from back then.

I reached out to several people over the course of 2-3 months. The two who pointed me in the right direction were are materials professor at Iowa State University and an engineer from Alcoa. They both told me the same thing.

Rivets are made from 2117 alloy which does age harden. It is possible to "soften" them by re-heating them. To do this correctly, you must heat them to their critical temperature which is 935 degrees. I used a dental oven a buddy of mine let me borrow (I still have it). The recipe is to heat for 15 minutes and then quench in water within five seconds. Quality control consists of hitting them on an anvil with a hammer. If they crack, you did it wrong. Don't drop them when you take them out of the oven!

I did it on my -4 and it was definitely noticeable in terms of ease of driving the rivet. I'm not doing it now, but it was a fun project. Like everything in this hobby, a great way to learn new stuff.

If you know a dentist, ask to borrow his oven and try it.
__________________
David
RV-8 QB
Tail - Done
Fuselage - In Process

Last edited by vomatic : 11-08-2020 at 07:48 PM.
Reply With Quote
  #14  
Old 11-08-2020, 11:47 PM
PCHunt PCHunt is offline
 
Join Date: Feb 2007
Location: San Diego, CA
Posts: 1,714
Default

Quote:
Originally Posted by vomatic View Post
Years ago when I was building a -4 I spent some time on this topic. Mostly because I wasn't very good at driving rivets and was looking for a easier way. I just dug out my notes from back then.

I reached out to several people over the course of 2-3 months. The two who pointed me in the right direction were are materials professor at Iowa State University and an engineer from Alcoa. They both told me the same thing.

Rivets are made from 2117 alloy which does age harden. It is possible to "soften" them by re-heating them. To do this correctly, you must heat them to their critical temperature which is 935 degrees. I used a dental oven a buddy of mine let me borrow (I still have it). The recipe is to heat for 15 minutes and then quench in water within five seconds. Quality control consists of hitting them on an anvil with a hammer. If they crack, you did it wrong. Don't drop them when you take them out of the oven!

I did it on my -4 and it was definitely noticeable in terms of ease of driving the rivet. I'm not doing it now, but it was a fun project. Like everything in this hobby, a great way to learn new stuff.

If you know a dentist, ask to borrow his oven and try it.
Or, alternatively, just buy new rivets. Rivets are cheap. Too much time and effort for me, but as you say, a good education!
__________________
Pete Hunt, [San Diego] VAF #1069
RV-6, RV-6A, T-6G
ATP, CFII, A&P

2021 Donation+, Gladly Sent
Reply With Quote
  #15  
Old 11-09-2020, 10:43 AM
Marc Bourget Marc Bourget is offline
 
Join Date: Apr 2009
Location: Stockton, California
Posts: 323
Default

Buying new rivets worked well in the early 70's in SoCal with all the Aerospace activity. Thursday morning at Fullerton Air Parts (Aircraft Spruce at that time was "down the street, dealt only with wood and was by appointment only) got you rivets that would drive at 60 psi or so, raising to 80 psi by Saturday.

I had access to "professional" HT ovens, analog controlled, and following the above procedure, gave you rivets that drove at 40 psi, barely "tickling" the rivet gun trigger, "plop, plop, plop, plop" If you kept them on dry ice, the pressure requirements increased more slowly, but eventually got to 80 psi or more after a few days. Soft rivets drive with minimal, if any, distortion of the surrounding sheet metal as the clinch pressure was less or equal to the "stretch" resistance of the skins you were riveting.

935 deg F, yes, but you need a digital controller now. The old analog controllers were +/- 10 deg and you risked exceeding 938 deg, which scrapped the rivets.

Also, only anneal clear anodized rivets. Annealing colored rivets is a chemical no-no.

Onward and upward

Last edited by Marc Bourget : 11-09-2020 at 10:45 AM. Reason: added comment on sheet distortion
Reply With Quote
  #16  
Old 11-09-2020, 04:52 PM
fl-mike's Avatar
fl-mike fl-mike is offline
 
Join Date: Jul 2005
Posts: 1,461
Default

It was a fun experiment to solution heat treat some rivets back in the 90's. I did some and tested them on a material tester. The sheared right at book value. Older age hardened samples sheared higher than book.
Freshly treated rivets can be squeezed with a pair of pliers, and universal heads can easily deform or slide off to the side. Flush rivets would lose the dimple. Fun stuff, but I would only do that for special situations like riveting the hinges to fiberglass, or a tricky trailing edge rivet. Unfortunately, I burned out my oven elements annealing some stainless steel this year, so I'm probably out of luck for future treatments.
__________________
Mike W
Venice, FL
RV-6A. Mattituck TMX O-360, FP, GRT Sport EFIS, L3 Lynx NGT-9000
N164WM
N184WM reserved (RV-8)....finishing kit in progress. Titan IOX-370
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 09:28 PM.


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.