Re: ATM A 100% Sharpie Test?

[Jerry Palmer <w6cwj@earthlink.net>]

isnt it zyglo rather than magnaflux?

jerry
venice,ca

Dan Cassaro wrote:

> Nils Olof,
> Using my incredible grasp of the very obvious, I just realized this is
> already being done every day all around the world.  It's basically a
> Magnaflux test.
> I worked in a machine shop one summer many years ago, and using a
> flourescent penetrating dye (oil based!) and then UV is how they test
> parts made in the factory.
> Check out http://www.magnaflux.com for the details...
> I'll send them an email and see what advice they have to offer, and then
> report back to the group.
> This might just work....
> Dan
>
> Dan Cassaro wrote:
>
> > Nils Olof,
> > That is *brilliant*  (pun intended). I was going to use red Dykem as
> > John Upton suggested, but pits that fluoresce basically scream "Here I
> >
> > am!", instead of hiding... Wow.
> > Let's seem if anyone has a suggestion for the ink, and I'll start
> > searching on my own...
> > Dan
> >
> > Nils Olof Carlin wrote:
> >
> > > Dan,
> > >
> > > >A crazy thought:  could one spray the entire surface of a fine
> > ground
> > >
> > > >mirror, thus filling all the pits with ink, let dry, and then grind
> >
> > > >until *all* the black pits were gone?  It would certainly make
> > > finding
> > > >pits much easier...
> > > >Has anyone tried this?
> > >
> > > Not I, half an hour ago. But why wonder, if you could do a pilot
> > > study? I took two slide glasses, beveled the edges with a stone for
> > > safety. A few seconds with #150 grit produced some nice test pits,
> > to
> > > color with a layer of "sharpie" ink. After a wet or two of #400
> > grit,
> > > I could see with a magnifier some pits were indeed inked, but not
> > all.
> > >
> > > Then the thought struck me - would fluorescent ink be any good,
> > using
> > > a UV "blacklight"? First try showed my yellow underline pen was
> > > water-soluble - so I had to do my next #400 "wet" with a drop of
> > salad
> > > oil instead. With the glass near the UV light, the remaining pits
> > were
> > > very much more conspicuous this way, so if you could get a water
> > > resistant fluorescent "sharpie" (I'm sure there must be), the
> > > sensitivity of the test would likely be very much improved.
> > >
> > > And you would know for sure if the large pits are left over from the
> >
> > > old, coarse grit or are from the new, finer one.
> > >
> > > Just a pilot study, any volunteers for a full-scale one? ;-)
> > >
> > > Nils Olof
> > >
> > > In case you wondered: no UV seems to pass my glasses, at least
> > holding
> > > them between the light and a paper kills all fluorescence.