On Sun, 07 Jun 2015 18:25:11 +0700, John B. wrote:

On Sun, 07 Jun 2015 01:42:48 -0500, Tim Wescott
wrote:

On Fri, 05 Jun 2015 17:04:29 -0500, Tim Wescott wrote:

I'm looking for product names to look for.

I'm working on an instrument for a customer, and he's having me do the
whole-system design. This means I'm out of my comfort zone and
playing with mechanical issues.

It needs a big outer case (well, four feet long, by nine inches by
two).
I'm thinking of doing the outer case from fiberglass for a number of
reasons, not least of which because I'm familiar with its
characteristics, and the instrument is going to be used on or near
bodies of water including salt water.

I'll need to attach things to this outer case. My current thinking is
to used buried studs and/or nuts, and use thumb-nuts and thumb-screws
to actually attach the bits. I'm assuming I want to use brass or
stainless hardware for corrosion resistance, and I probably want to
take some pains to match alloys.

McMaster is failing me for appropriate hardware. I'm finding
thumbscrews and thumb-nuts, but I'm not coming up with good candidates
for nuts that I can bury in the fiberglass. I'm assuming that the
case will be a two- part assembly that's glued together; nuts that can
be buried in one side and then captured in the gluing-up process seem
to be the best notion to me, but if someone with actual experience has
alternate suggestions, I'll listen (I may not _take_ your suggestion,
but I'll certainly _listen_ and _think_ about it).

So -- suggestions? I'm probably wanting some 4-40 or 6-32-ish sized
ones, and some 10-24 (or 1/4-20). The bigger ones may work better as
studs, with thumb nuts. I'm pretty sure that I want nuts for the
little ones, unless that presents severe difficulties.

Your responses made it clear that I left out an important part: the case
will be made with two or three fiberglass bits, glued together and
finished. I'm envisioning the fasteners going into the top piece, then
getting captured by the bottom piece, or perhaps some inner third piece.

The usual scheme with molded fiberglass is to (hopefully) build a mold
that does everything in one fell swoop. Failing that, two parts that fit
together as they come out of the mold. Cutting and trimming little bitty
pieces and gluing them in and maybe coming back the next day to laminate
a little cloth over them to make them stronger is a time consuming
process and results in "things" that aren't all the same and bits that
fit "Thing #1" probably won't fit in "Thing #2".

Thank you very much for your expertise. My family has been making car
parts out of fiberglass since 1957, so we may actually have some clue of
how the stuff works.

--
www.wescottdesign.com