Rivet Direction/Shop head vs. Factory head ?

[Jeff Moreau]

Does it make a difference which side you put the factory head of the rivet on when riveting.
I am begining to rivet the rear spar of my vertical stab and wasn't certain if it matters. Obviously I know the proper direction for a hole that is countersunk, but I am wondering about the universal head rivets. I believe I read somewhere that the factory head of the rivet shoud be against the thinner of the two surfaces being riveted. Is this the case?
Any comments or suggestions are welcome.
Thanks in advance for the help.

[Steve]

I though tlike you, factory head on thin mat'l. I asked the same question of Vans engineer. He said it really doesn't matter because the material thicknesses are almost identical so it's purely a matter of aesthetics. For example, I've seen the rivets on the HS attach brackets riveted to the front spar both ways.
Steve

[728GD]

When I built mine, I generally based the direction of the rivet on access for my rivet squeezer, or in the case of having to drive the rivet, access for the bucking block and rivet gun. I chose to insure a good clean rivet over which side the shop head or the factory head was on.

[Guest]

[quote="Jeff Moreau"]Does it make a difference which side you put the factory head of the rivet on when riveting.
Obviously I know the proper direction for a hole that is countersunk, but I am wondering about the universal head rivets. I believe I read somewhere that the factory head of the rivet shoud be against the thinner of the two surfaces being riveted....

Generally speaking, the manufactured head is located atop the thinner material in a stackup. There is wiggle room here. For instance, you may reorient the head to facilitate access with a squeezer or a bucking bar or simply for cosmetic reasons. I pounded rivets professionally for McDonnell-Douglas for many years and only in very rare circumstances was the solid rivet head orientation specifically called out. In most cases, it had to do with the manufactured head interfering with an adjacent component so the orientation was reversed and the shop head flushed by countersinking. We don't have to worry about such things with our RV's.

[jim_geo]

Here's one I just had to throw my $.02 in on. Today while riveting my seat backs I was trying to put all my factory heads toward the front mostly for looks. After drilling out three rivets I gave up on that idea. The construct along the vertical outside edges of the seat back is corrugated sheet aluminum and .125 AA. Upon squeezing the shop head on the sheet side I had a definite gap between materials. As it turned out it was impossible for me not to get a gap and some amount of deformation in the sheet around the rivet hole. Once I made the decision to put those shop heads forward the joins were tight and solid. I was relieved tonight to find this thread as I have always kind of wondered if there was an absolutely correct direction to place rivets.

[johnk]

I have generally followed the guidance of putting the factory head on the thinner material, but when I've done it the other way I don't think I've noticed any visible difference. As others have noted, it's probably better to do it the other way if it provides better access for your tools, since you'll probably get a better rivet that way. One other factor is that rivets are easier to remove when you have clear access to the factory head for a drill.
John

[johnk]

jim_geo,

Thanks for the photo, two questions:
(1) I can't tell for sure, but is the bottom connection of the seat back somehow adjustable?, it almost looks like a piano hinge with three fore/aft positions.
(2) What is the nice-looking shiny gray paint?

Thanks
John

[N537TM]

I had the same problem on my seat backs ..jim. The alum skin would not stay flush to the angle... drilled out 4 or 5 before I tried it the right way.

I have a talked to many Old rivetbangers about this subject and the best story that I got...was from an engineer that worked at Douglas when they were building the C-47... DC-3 mil version...
His story was that on the drawings for the plane ... a note is posted stating that Shop head is alwys on thick side....

We were instructed at Alex tech to do it his way when ever possible, seems to make most affect when the thicness are extreamly different, like here on the seat backs.

You project looks sweet jim...

Mike B.