On Thu, 24 Dec 2009 12:01:18 -0500, the infamous Joseph Gwinn
scrawled the following:
In article ,
Larry Jaques wrote:
On Wed, 23 Dec 2009 11:07:04 -0500, the infamous Joseph Gwinn
scrawled the following:
In article
,
"Denis G." wrote:
McMaster Carr has countersunk stainless steel solid rivets:
http://www.mcmaster.com/#solid-rivets/=5228i4
They might look less obvious..
I did think of this, but there is a twist. The bowl material is too
thin to countersink, but there is a standard dodge from the airplane
industry - one countersinks the piece to which the sheet will be riveted
(the foot in the present example), and dimples the (bowl) sheet to
match. But it's going to require some tooling to make those dimples in
stainless steel sheet.
Excellent! Now you have a solid reason for new tools, Joe. Getchersef
a brand-spankin' new doming die/dapping punch set!
http://fwd4.me/9LD Griz $80ish
http://fwd4.me/9LJ HF $45ish ($36 local, GO FOR IT!)
http://fwd4.me/9LL eBay dapping punches, $20ish
eBay dapping block, $67ish
http://fwd4.me/9LF Amazon $46; brass, may be too soft.
There's a thought - tools!
Dapping blocks and punches are not the same thing as a rivet head
forming punch. But I bet McMaster carries the correct tools.
Um, I thought you wanted to deform the colander foot holes, forming
them for the head of the rivet. shrug
Or, for one use, I could make the tools from soft steel.
"If you get the chance to buy tools, go for it!" I sez.
This dimple-the-sheet method is the reason for 100 degree flathead
screw/rivet heads: In WW2, it was found that the aluminum sheet used
for airplane skins could be cold dimpled to 100 degrees included angle
without cracking, but 82 degrees was too severe. (Don't know about the
90 degree heads used in metric screws, but I bet that 90 degrees is also
too severe.)
So did heat make a difference, or was it just not doable with that
particular alum. alloy?
No, the issue was that it was too slow and too hard to heat the airplane
up, and a WW2 airplane had tens of thousands of rivets holding it
together.
Yeah, that might take 3 hands.
--
REMEMBER: The sooner you fall behind,
the more time you'll have to catch up!