Platinum Pacer Wings

[mmoyle]

Spoke with Charlie Center today. I described the issue with the lack of a wing rib at the gap between the aileron and flap for mounting the fence. We talked about either placing another rib in that location or fabricating a channel formed to the rib profile and secured to the false spar, rear spar and front spar. Charlie asked if the PA20 was in the utility category. Then Charlie said the PA20 and 22 have that problem but the PA18 doesn’t. He said it was my choice, install another rib, fabricate a channel or mount to the rib closest to the flap/aileron gap. I then asked what the stall fence 3/4” X .0625 angle was made of? 6061... I’ll be ordering forty thousandth 2024T3 and the aluminum angle from ACS and make another set of stall fences. Anneal a batch of rivets for the fence and will use two round rivet dies to round the bucked end of the rivets...for sh...its and giggles and it’ll look better.


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[Steve Pierce]

So what is your process for annealing rivets? I have seen ice box rivets but never seen a process for annealing AD rivets that work hardened them back to the intended hardness. I could see annealing if you were trying to drive #5 or#5 rivets into .020" aluminum but I have not had a problem driving a 3/32" or 1/8" rivets in the same.

[Stephen]

I am confused about your annealing. Are you annealing AD rivets?

[mmoyle]

Knew the annealing or heat treating of AD rivets would be questioned. I did a quick google search...nada. I’m looking for the literature on annealing/heat treating 2117T4 rivets....I have it on an old DOS box I think. I’ll email Marc Bourget and Kent White and post up the information when I find it or receive it from either. I agree with Steve. AD rivets are designed to be driven as received. But sometimes circumstances call for softening up the AD rivets. For instance.. I did practice riveting .025” 2024T3 to the .020” 6061 false spar with 10 year old AD rivets.... had to use a bucking bar with a bucking surface at a 45 degree angle to get into that very tight space. The as received AD rivets took more force to set. Eight out of the ten practice rivets deformed the 6061. Because I dimpled the 6061, bucking the hard AD rivet enlarged the hole to nearly the diameter of the mashed end of the rivet... The bucking bar was difficult to hold in place....it dance around a bit and marred the concaved surface of the false spar which was visible from the back side of the false spar. Driving the hard rivets also caused the deformation at the edge of the concaved shape of the false spar. With softened rivets the air pressure to the rivet gun was reduced to just enough to set the rivet... no deformation.....and the softened rivets didn’t enlarge the drill hole.

On the rounding the bucked end of an AD rivet...try it. Doesn’t work well. Rounds the end of the rivet a bit. Annealing the same rivet will allow you to mash it into a rivet head shape. Isn’t necessary...but is my version of fun..why not?


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[Stephen]

The quality of your work is outstanding. I am interested in your resoning.

How does an annealed AD rivet differ from a standard A soft rivet?

[mmoyle]

AD rivets are made from 2117. D or icebox rivets are made from 2017T something and 2024T3 is the DD rivet. Both AD,D and DD rivets behave in a similar fashion when heat treated, heated to 930-960 for one hour (depending upon the publication) in still air. Immediately quenched in ice water then placed into an ice box at ten below zero until immediate use....quenching the rivets is the key to creating soft malleable rivets. During WW2 the big boys used ovens specifically designed to heat treat rivets. The bottom of the heat treat ovens were equipped with trap doors. When it was time to quench the rivets....pull the handle...dump the rivets into a bucket of ice water.....almost instantaneous quench...whereas my method isn’t exactly instantaneous...close to instantaneous by using crucibles designed for fire assaying of precious metal ore samples. The crucibles maintain the heat long enough to go from the oven to dumping into ice water...not perfect but it works. Both AD and DD rivets age harden over time to their respect tensile strength specifications. 2024T3 rivets age harden to an undriveable state within 20 minutes of removal from the freezer. 2017 rivets harden to an undriveable state in about one hour. AD rivets....since I don’t have the literature handy I can’t say how quickly they age harden...somewhere between 20 minutes and one hour after removing from the ice box.

And if....I had the correct tank bay false spar parts....My need of social interaction/sharing.....the heat treating of AD rivets wouldn’t have happened.


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[mmoyle]

Opps...didn’t answer the soft rivet question.. the non structural soft rivets are made from 1100 and maybe 3003 aluminum...don’t recall. Both are soft and malleable. Neither will work harden or age harden. Wonder why they don’t make rivets from 5052H32? That stuff is slick to work with. Is considered a marine grade aluminum. Is resistant to corrosion and is super easy to anneal at 875 degrees..maybe 750 degrees...I’d have to look it up. Work hardens as it is shaped, annealed and shaped some more....annealed and shaped...for ever


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[mmoyle]

Steve...please check your email...Sent you the documentation as I’m unable to attach a PDF from Tapatalk for some reason?


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[Jim]

Hi,

......Wonder why they don’t make rivets from 5052H32? Maybe they do.

http://acerivet.com/category/fasteners/buck-rivets/

[Steve Pierce]

And if....I had the correct tank bay false spar parts....My need of social interaction/sharing.....the heat treating of AD rivets wouldn’t have happened.

So you didn't' get the extended false spar channel?
24 gal tank hdw.jpg