Rivet advise please

On Aug 21, 2:00*pm, Michael Horowitz wrote:

Bob - thanks for your reasoned response. I'd like to hear more about
how you lined the drift along the rivet axis so that you got a
symetrical mushroom head - Mike

Mike, I just held the drift as straight as I could eyeball it and
whacked it with a claw hammer. There are a couple relevant photos in
the latest HP-24 project update:

http://www.hpaircraft.com/hp-24/update_25_aug_08.htm

Thanks, Bob K.

On Mon, 25 Aug 2008 14:44:51 -0700 (PDT), Bob Kuykendall
wrote:

On Aug 21, 2:00Â*pm, Michael Horowitz wrote:

Bob - thanks for your reasoned response. I'd like to hear more about
how you lined the drift along the rivet axis so that you got a
symetrical mushroom head - Mike

Mike, I just held the drift as straight as I could eyeball it and
whacked it with a claw hammer. There are a couple relevant photos in
the latest HP-24 project update:

http://www.hpaircraft.com/hp-24/update_25_aug_08.htm

Thanks, Bob K.


That's just as I've envisioned and tried, except I was using standard
head rivets (placed in a slight indendation in my anvil to hold the
head). I thought maybe my problem was using hard rivets, but that's
what you are using - Mike

Michael Horowitz wrote in
:

On Mon, 25 Aug 2008 14:44:51 -0700 (PDT), Bob Kuykendall
wrote:

On Aug 21, 2:00Â*pm, Michael Horowitz wrote:

Bob - thanks for your reasoned response. I'd like to hear more about
how you lined the drift along the rivet axis so that you got a
symetrical mushroom head - Mike

Mike, I just held the drift as straight as I could eyeball it and
whacked it with a claw hammer. There are a couple relevant photos in
the latest HP-24 project update:

http://www.hpaircraft.com/hp-24/update_25_aug_08.htm

Thanks, Bob K.


That's just as I've envisioned and tried, except I was using standard
head rivets (placed in a slight indendation in my anvil to hold the
head). I thought maybe my problem was using hard rivets, but that's
what you are using - Mike


That is the way almost every Sonex builder sets the 300ish solid rivets in
the wing spar.

--
-- ET :-)

"A common mistake people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools."---- Douglas Adams

On Aug 25, 4:25*pm, Michael Horowitz wrote:

That's just as I've envisioned and tried, except I was using standard
head rivets (placed in a slight indendation in my anvil to hold the
head). I thought maybe my problem was using hard rivets, but that's
what you are using - Mike

The universal head rivets are definitely harder to drive with a hammer
and anvil, they do tend to squirm around more. For them I usually
either enlist help to hold the parts in position or I just squeeze
them or use a rivet gun. When I hammer drive them I'll usually anchor
a 3/16" shank squeeze set onto the anvil to cup the head.

I'm helping a friend build an RV-8, and we just encountered an awkward
situation where we absolutely could not get a rivet gun onto the head
of a certain couple of rivets without removing the engine. What we did
instead, and this worked out pretty well, was to drill a 3/16" hole in
a bucking bar and anchor a universal-head rivet set in it. One of us
held the bucking bar and rivet set against the manufactured head of
the rivet, and the other used a back-riveting set in the rivet gun to
hammer on the shop tail end. Worked just fine.

For some tooling or test parts I just set the universal head on the
vice, hammer the shop end with a drift, and accept the fact that the
flat surface of the anvil leaves a flat spot on the universal head.
That's how I set rivets for the test coupons I break when
demonstrating the Break-O-Tron to schoolkids, and they've never failed
to do at least the specified 26 ksi.

Also, it takes virtually zero investment to practice some of the
techniques I describe. A half- or quarter-pound of rivets is only a
few dollars, and you'll probably get way more rivets than you'll
actually need. Get some bits of scrap and practice. If the first three
or five don't come out right, just keep trying different methods until
you start seeing the sort of rivets you'd expect on a Piper or Cessna.

To the degree that there's a point here, it's that there's a ton more
ways to drive hard rivets than there are pretty pictures of in the A&P
study guides and AC43.13. In addition to the techniques described
above, I've set rivets inside box beams using tiny hydraulic rams,
I've built suspended bucking bars to buck rivets inside those same
boxes, and I've milled many custom bucking bars to get to and form
awkwardly located shop tails. I guess it's sort of like what they say
in NASCAR: If it's stupid but it works, it ain't stupid.

Thanks, Bob K.

In article
,
Bob Kuykendall wrote:

On Aug 21, 2:00*pm, Michael Horowitz wrote:

Bob - thanks for your reasoned response. I'd like to hear more about
how you lined the drift along the rivet axis so that you got a
symetrical mushroom head - Mike

Mike, I just held the drift as straight as I could eyeball it and
whacked it with a claw hammer. There are a couple relevant photos in
the latest HP-24 project update:

http://www.hpaircraft.com/hp-24/update_25_aug_08.htm

Thanks, Bob K.

That is a sure way to booger up a rivet! Use the proper tools! The cheap
"air hammers" available from Harbor Freight, etc. do not work well --
they have the wrong stroke.

I have an adjustable-orifice valve on all of my rivet guns, to regulate
the frequency and intensity of the strokes. For An3-type rivets, it is
set down to go tap-tap-tap-tap and works very well.

--
Remove _'s from email address to talk to me.

On Aug 25, 5:23 pm, Orval Fairbairn
wrote:

That is a sure way to booger up a rivet! Use the proper tools! The cheap
"air hammers" available from Harbor Freight, etc. do not work well --
they have the wrong stroke.

I'm not sure I understand. I'm whacking a steel drift with a hammer of
the steel-head-on-handle variety, there are no pneumatics involved.
The hammer at hand was a claw hammer of the sort on every carpenter's
tool belt, but I've also used machinists hammers, ball-peen hammers,
dead-bow mallets, and also the back side of the odd monkey wrench. It
was all good, or at least good enough.

I imagine that if I did have my HF "heavy duty" air hammer handy, a
good whack on the drift with its barrel would have done the trick. As
you point out, its binary trigger and rough action sure enough make it
pretty worthless as a rivet-driving tool of the pneumatic variety.

And yeah, your point about using the proper tools is well taken. But
we're just exploring the boundaries of what constitutes good-enough
tools.

Thanks, Bob K.