Dear All
Since older people need 8 times the light input to see as well as a younger
person I had another material which lets in more light but blocks UV (b & a)
almost entirely. It is VE003.
The Brown 504 which is the normal Europa dark brown windscreen material
starts transmitting UV (b) (300 or so nm) and transmits about 35% at 380 nm.
It transmits UV (ba) to 400 nm about 40%. Light and heat over 600 nm is
transmitted from the source used in the test about 65 to 70% up to 1600
nm.according to the graph supplied me.
JR (Bob) Gowing in Oz Kit 327
----- Original Message -----
From: "Rob Housman" <ROB-HOUSMAN@worldnet.att.net>
Subject: Re: Use of White Pigment with Ampreg 20
> It is a common mis-conception that glass blocks 100% of the UV light.
Check
> this link http://www.jersey.net/~edsci/techsup/GlassCurve.pdf for a graph
> showing transmission at various wavelengths for 5mm thick glasses.
>
> The UV portion of the spectrum is generally taken to be 400nm or less
> (1000nm = 1 micrometer, or 1 micron if you prefer). In this list I am
> familiar only with the first three types listed: Borofloat would be
similar
> to window glass, Pyrex is Corning's name for tempered glass, and BK7 is
> commonly used for mirrors or lenses.
>
> Optical plastics, e. g., CR-39 and polycarbonate that are used in plastic
> eyeglass lenses, have UV absorbers in the mix but I doubt that the windows
> in the Europa have an absorber, and your experience confirms this
suspicion.
>
>
> Best regards,
>
> Rob Housman
> A070
>
>
> ----- Original Message -----
> From: "LTS" <lts@avnet.co.uk>
> Subject: Re: Use of White Pigment with Ampreg 20
>
>
> > I am not on a topic that I know much about here but:
> >
> > 1 I thought Rayban used glass in their sunglasses for 100% UV
block????
> > 2 I get a great sun tan whilst flying and I have a plastic canopy????
> >
> > Jerry
> > LTS@avnet.co.uk
> > www.avnet.co.uk/touchdown
> > ----- Original Message -----
> > From: "J R (Bob) Gowing" <gowingjr@acr.net.au>
> > <roger.mills@btinternet.com>; <europa@avnet.co.uk>
> > Subject: Re: Use of White Pigment with Ampreg 20
> >
> >
> > > Thank you fellas for your comments.
> > >
> > > Dave S, I take your point that the UV is a serious matter and that is
> the
> > > reason for my reply to Roger as follows:-
> > >
> > > Roger, I put a lot of laminated glass in the front extension of our
> > house -
> > > to get the plastic layer in between the 2 layers of glass. That is the
> > part
> > > that keeps out the UV.
> > >
> > > Fred F, I intend taking your advice and forget about using any White
> > pigment
> > > in the epoxy itself.
> > >
> > > Thank you all for your inputs.
> > > Sincerely
> > > JR (Bob) Gowing in Oz Kit 327
> > >
> > > ----- Original Message -----
> > > From: "Dave Simpson" <davesimpson@londonweb.net>
> > > Subject: Re: Use of White Pigment with Ampreg 20
> > >
> > >
> > > > Bob,
> > > >
> > > > At work, a sub-contractor used white pigment in the epoxy/glass lay
up
> > for
> > > a
> > > > very large radome mounting ring (3m dia.) for a microwave test site.
> > The
> > > > rig has been completely outdoors for almost 4 years now and shows no
> > sign
> > > of
> > > > UV degradation. It also has a blue foam base. The laminate was
much
> > > > thicker that our Europas but the environmental exposure was more
> severe
> > > too.
> > > >
> > > > Dave Simpson
> > > >
> > > > ----- Original Message -----
> > > > From: J R (Bob) Gowing <gowingjr@acr.net.au>
> > > > Subject: Use of White Pigment with Ampreg 20
> > > >
> > > >
> > > > > I have just read the pamphlet that came with my latest supply of
> Slow
> > > > > Hardening Ampreg 20 and 2 year shelf life. It states that up to
10%
> by
> > > > > volume of SP epoxy pignents can be added to the resin component
and
> > then
> > > > > this mix can be combined in the same old weight ratio of 100:25.
> > > > >
> > > > > It may be that using the available white pigment in the finishing
> > phase
> > > > > might reduce the amount of paint needed for satisfactory cover and
> UV
> > > > > protection.
> > > > >
> > > > > Has anyone something useful to report about using SP white pigment
> in
> > > the
> > > > > mix to finish their wings?
> > > > >
> > > > > JR (Bob) gowing, Kit 327 in Oz.
> > > > >
> > > > >
> > > > > The Europa List is supported by Aviators Network UK -
> info@avnet.co.uk
> > > > >
> > > >
> > >
> >
> >
>
>
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