Phil Addison wrote:
On Mon, 15 Jun 2009 10:33:47 -0700 (PDT), in uk.d-i-y NT
wrote:

On Jun 15, 3:44 am, NT wrote:
Another one to play with:
OK, after feedback here's version 2 for comment. Taught me a thing or
2.



Head types
* lost head - the head comes away
* the other one, leaves no hole

What's this? Is it to just fill spurious holes? cant see how it holds
pars together.

I was confused with this in the original post until just after I wrote
my explanation of what it means.

Take any rivet and it will have a pre formed head. In the case of pop
rivets, it will have a mandrill that protrudes through the head and the
other end of the mandrill will have a bulb type shape. This end of the
rivet is known as the tail.
The mandills come in 2 types, break stem and break head (not to be
confused with the true head of the rivet that has the pre formed shape.
See my original post regards how the two types work.

==Solid rivets==
Solid rivets are inserted into the hole and hammered flat, with the
workpiece resting on an anvil or similar. This is a much slower
process than blind riveting, and requires access to both sides of the
hole. The method has been in use for many centuries.

Yikes... not if you want a decent joint. Hammering won't pull the two
parts together, doing this will usually result in a loose joint. You
should use a pair of clamps either side of the rivet location to firmly
clamp the parts together. The rivet expands diameterwise as you hit it,
including the bit in the small gap between unclamped parts. That
expanded disk will prevent any subsequent attempts to squeeze the parts
together.

Cleanliness is important as grit trapped between the parts will weaken
the joint.

If you are doing serious riveting where a number of rivets are used
along a joint line, you can get* neat little clamps that are inserted
through each hole (needing access from one side only) to pull the job
together. Then one is removed at a time and a replaced with a rivet.

* as used in aircraft industry. Don't know where DIYers get them, but I
have a few.

I described a way of drilling off and rivetting a job with lots of
rivets some years ago. Basically, you drill off the holes, but leave
some below size. Strip the job apart and clean up after de burring. Put
the joint back together with the interfay, if any, between the joint and
then use under sized rivets to hold the job in tight contact. Fit most
of the rivets and drill out the tack rivets, open the holes up to final
size and rivet up.

Also you don't rest on an anvil as the a head has to be formed on both
sides, you use a 'set' held in the vice for the dome head and another
set to form a dome on the tail (you hammer on the tail not the dome
end).

If you want to do this the posh way for hand rivetting :-)

Professionally, the rivets are gunned from the head side using a
pneumatic rivetter. The tails are usually left without a dome.

Rivet length: Correct length is important as the tail needs to be just
the volume needed to form the head.

As a general guide, the tail of the rivet should stick out of the back
of the job about 1.5 to 1.75 times the diam. of the rivet. Certainly no
more, this goes for pop rivets as well. This should give you a good tail.

Head types
Countersunk heads should be used for the countersinking described
earlier.

These rivets are usually copper, steel or aluminium. Steel rivets are
often worked hot....

.... because they shrink on cooling to achieve a tighter joint.

The final appearance is a flat disc, a domed head or countersunk. Its
possible to produce a flush finish in thick sheet with a countersunk
rivet.

I believe this is only possible if you use csk head rivets. It is the
norm for aircraft ally skin fabrication.

A tool is best used for forming the domed head with small rivets -
think it's called a 'set'. Also has a hole in it the size of the rivet
to assist in getting both parts of the work mating properly - if this
is not done it affects the strength of the joint, as well as looking
unsightly.

Essential to use correct set to match the rivet head if you want an
engineering joint, ie different ones for different rivet diameters.

Of course for a DIY job, just hammering on the tail may be good enough!

--
Phil