Date: Sun, 13 Oct 2002 12:35:39 +0100
Reply-To: Clive Smith <clive.harman-smith@NTLWORLD.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Clive Smith <clive.harman-smith@NTLWORLD.COM>
Subject: Re: Removing Luggage Rack Pop Rivets
Content-Type: text/plain; charset="iso-8859-1"
Might I suggest that you try a drill somewhat LARGER than the nominal pop
rivet size and ease off and stop when the rivet head runs up the drill bit?
When the holes for pop-rivets (or any clamping style fastener) are first
drilled, they should always be 'clearance' which for 1/8" is a No. 30 drill
(0.12875", giving 3% clearance against the nominal shank size).
When drilling them out, this is the drill size I would always grab, as all
you want to do is take the head off and stop as soon as you start chamfering
the plate being fastened and then punch the rivet out from front to back
rather go right through the job. This means you'll less likely to enlarge
the hole making subsequent re-rivetting a bodge job.
Note that pop rivets come in many styles, steel, ally, copper but most
importantly some are designed to 'seal' and leave the steel shank in the job
whilst others are meant to break off so as to leave a hollow rivet. 'Tucker'
pop rivets are the originals and have been copied extensively, in a narrower
product range then Tuckers and to much less rigorous quality standards so
that they very break off inconsistently, sometimes leaving a tail, a steel
ball in the tail, or the shank sticking out the front even. Very often this
is also because the fitter has not measured the combined job thickness and
failed to use a rivet of the correct length, giving a long tail with
insufficient compression (and the shaft fails to break altogether) or a
short tail which means the shaft breaks prematurely or the rivetting pliers
are not powerful enough to swage the tail at all.
Sorry for the discourse, the point being that if the steel shank is still in
the rivet you'll have fun, and if the rivet is loose, as Frank says, it'll
likely spin, at which point angling the drill around and pushing a lot
harder usually works, though jamming it from the back somehow is
occasionally necessary. If the rivet is ally or copper you'll have no
trouble. Having done several thousand over the years, its a bit of an art,
but most people aren't after a clean undamaged job afterwards, wehreas I
usually was (hang gliders, vehicle, aircraft and other structurally
important parts).
So when re-riveting ensure the surfaces are flat (the holes are deburred
properly), well clamped up first (else the rivet will expand between them
and force a gap - v. bad) and that the rivet has the correct length (do a
quick trial first, if its a strength job). A smearing of chromate jointing
compound between the parts would also ensure corrosion doesn't get a hold
(usually different metals are involved, ally/steel being typical).
Many think that pop rivets are just a quick cheap solution to hold
unstressed parts together, but designed, specified and fitted correctly,
they can be used on highly stressed components, and often were in the
aircraft industry where their origins no doubt lie.
PS. Clearance for 3/32" is I seem to remember a No 41 drill. The Imperial
drill sizes, bolts, threads and number and letter drills were a very
sophisticated tried and tested system - the metric system seems a lot harder
to work with, despite the fact that its supposed to be simple (= crude,
arbitrary sizes), the equivalents often don't exist - lets hear it for
Imperial measurements - a foot's a foot after all!
Clive
'88 Syncro Transporter
----- Original Message -----
From: "Frank Condelli" <RAlanen@AOL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, October 13, 2002 10:31 AM
Subject: Re: Removing Luggage Rack Pop Rivets
In a message dated 10/12/2002 3:08:21 PM Eastern Daylight Time,
LISTSERV@GERRY.VANAGON.COM writes:
> I want to replace my luggage rack tie downs, I have figgured
> out how to get the rack off, but now that its off I can't
> figure out how to get the pop vivets out. Any ideas?
>
Chris, the pop rivets can be drilled with a drill bit of a somewhat
smaller size than the pop rivet so you end up cutting off the head of the
pop
rivet. If the pop rivet spins then you will need to find a way to hold it
from spinning from the opposite side while drilling and not using a lot of
pressure on the drill.
Cheers
Frank Condelli
Almonte, Ontario, Canada
<A HREF="http://members.aol.com/BusFusion/bfhome.htm">BusFusion</A> a VW
Camper camping event, Almonte, ON, June 12 ~ 15, 2003
'87 Westy & Lionel Trains
Member: <A HREF="http://www.vanagon.com/">Vanagon List</A>, <A
HREF="http://www.bcn.net/~limbo/">LiMBO</A>, <A
HREF="http://www.westfalia.qc.ca/">IWCCC</A> & Capital City VW Club
Vanagon/Vanagon Westfalia Service in the Ottawa Valley
<A HREF="http://members.aol.com/Fkc43/stebro.htm">STEBRO/Vanagon Stainless
Steel Mufflers</A>
<A HREF="http://members.aol.com/Fkc43/busindex.html">Frank Condelli &
Associates</A> or http://frankcondelli.com
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