Author: rick07x@... Time: Sat Aug 25, 2001 4:24 am PDT Link
After fitting and drilling skins to ribs and bulkheads, the only sure
way to prevent pucker around rivet heads is to remove all gap.
Usually, this involves making up a shim that can be quite tedious
work, especially those fabricated for eliminating a tapering gap.
And trying to fit this shim between a dimpled skin and bulkhead can
be frustrating. So I took a page out of my McDonnell-Douglas
experience. Under certain circumstances, and if the gap did not
exceed a certain tolerance, we used a fancy space age material
informally called "liquid shim". As homebuilders, most of us do not
have access to this rather exotic material, but I have used what is
available to all of us. I just mix up a small dixie cup of
fiberglass epoxy with lots of cotton flox to make it structural, tape
off the area to be shimmed, with disposable latex gloves on, shove
this material into the gap, filling all the local voids, let dry 24
hours, redrill the holes because if you did it right, the fiberglass
will ooze out the rivet holes, clean the dimples up, shoot the
rivets. Voila! Gap free, and a relatively light fix compared to a
metal shim in a fraction of the time.
Author: "Eric Newton" <enewton57@...> Time: Sat Aug 25, 2001 5:55 am PDT Link
That is probably one of the best ideas that I've read since starting
my projetc. Thanks for sharing it with us. I wish I would have
heard about this soooner as I'm almost finished. Well maybe the next
one. Too bad Dr. "un-impressed" took off so soon or he might have
benefited from your idea. ;>)
Eric Newton - Long Beach, MS
RV-6A N57ME (final stuff)
www.ericsrv6a.com
--- In vansairforce@y..., rick07x@e... wrote:
> After fitting and drilling skins to ribs and bulkheads, the only
sure
> way to prevent pucker around rivet heads is to remove all gap.
> Usually, this involves making up a shim that can be quite tedious
> work, especially those fabricated for eliminating a tapering gap.
> And trying to fit this shim between a dimpled skin and bulkhead
can
> be frustrating. So I took a page out of my McDonnell-Douglas
> experience. Under certain circumstances, and if the gap did not
> exceed a certain tolerance, we used a fancy space age material
> informally called "liquid shim". As homebuilders, most of us do
not
> have access to this rather exotic material, but I have used what is
> available to all of us. I just mix up a small dixie cup of
> fiberglass epoxy with lots of cotton flox to make it structural,
tape
> off the area to be shimmed, with disposable latex gloves on, shove
> this material into the gap, filling all the local voids, let dry 24
> hours, redrill the holes because if you did it right, the
fiberglass
> will ooze out the rivet holes, clean the dimples up, shoot the
> rivets. Voila! Gap free, and a relatively light fix compared to a
> metal shim in a fraction of the time.