RE: FROM NuArc was PPG Starphire Glass ( ?? Questioning My Data)

DEAR SANDY,
        Given that anything imported to Barbados costs between 3 and 6 times what
it costs in the first world (due to shipping, duty, and VAT) I don't think I
will be replacing anything too soon. I may consider it if I make a trip to
the US where I can buy them and sneak them in! I was more worried about
what to do if one of them gets broken when I move the unit into my new
darkroom.
        Thanks for the good point about having to replace both the main glass over
the vacuum frame and the heat shield glass. I am rather tall so unless I
bend down and look up into the head of the unit I forget that it is there!
                                        CHEERS!
                                                BOB

 Please check my website: http://www.bobkiss.com/

-----Original Message-----
From: Sandy King [mailto:sanking@clemson.edu]
Sent: Saturday, November 19, 2005 2:38 PM
To: alt-photo-process-l@sask.usask.ca
Subject: Re: FROM NuArc was PPG Starphire Glass ( ?? Questioning My Data)

Bob,

I don't want to offend you by stating the obvious, but if you were to
replace the plain float glass on a NuArc 261k or 26-1ks with any kind
of speciality glass that would allow better transmission of UV light
you would also need to replace the piece of tempered glass that
serves as a heat shield, and in some cases, diffuser. It also is
plain float glass, and though tempered, would become the weak link in
the UV transmission chain.

Sandy

>DEAR LIST,
> I don't know if this is useful to anyone but I received a reply to a
>question I sent to NuArc Tech services. They stated that they use
>"standard" glass but make sure it is perfect, i.e. no bubbles or ripples in
>it.
> CHEERS!
> BOB
>
> Please check my website: http://www.bobkiss.com/
>
>-----Original Message-----
>From: Eric Neilsen [mailto:e.neilsen@worldnet.att.net]
>Sent: Thursday, November 17, 2005 11:37 PM
>To: alt-photo-process-l@sask.usask.ca
>Subject: PPG Starphire Glass ( ?? Questioning My Data)
>
>After last nights back and forth, I was indeed going to call PPG.
>
>This required all of 3 minutes and a short wait for a return call. I
>received a call back from Penny Bridges. She has since faxed to me data for
>both the Starphire glass and SOLARPHIRE glass. The thinnest that the
>Starphire is listed as being manufactured is 1/8" or 3.3mm and all the way
>up to 3/4. The data sheets do differ somewhat from those I received in
1992
>as one would expect; most businesses update their literature. I received
>separate sheets for 4mm and 8mm and this one combines the information and
>transmission data in 10nm increments and only shows transmission data for a
>glass with a thickness of 5.66mm. It does not show up on the available
sizes
>but that is what is referred to in the chart.
>
>While it does not match my data, as one would expect from different
>thickness of glass, it does come darn close to the 4mm data that I have. It
>is not what I believe to be true as Sandy indicated in his email, but what
I
>know to be true based on the manufactures data. Penny said that they have
>not changed it since they first starting making it but do offer a coating.
>
>It took very me little effort and would certainly have been something that
I
>would have done if I were to include test information about a type glass in
>a book : ) But wait, that is what I DID back in 1992. It appears in my
book
>on platinum printing. I don't site all the data. But do talk about why and
>when one might benefit from using it.
>
>
>This data also talks about the infrared quality of the glass. I have not
>studied gum like I have studied platinum/palladium printing. It may be that
>Judy's experience with Starphire has something to do with other
>characteristics of the glass that are not beneficial to the chemistry she
>used.
>
>
>At this moment, I can't lay my hands on them which does bother me. I took
>them out of my notes to make copies for some students and can't locate
them.
>I do however, have the data for the 4mm which is what Sandy googled.
>
>I will however, be glad to post PDF's of the documents after I receive them
>in the mail. The faxes are OK, but I'd rather wait at least until I have a
>chance to print them with my higher quality printer. I am sure she'll fax
>them to you too Sandy.
>
>The PPG web site that I posted last night has their phone number. I suggest
>calling them.
>
>
>
>
>Eric Neilsen Photography
>4101 Commerce Street, Suite 9
>Dallas, TX 75226
>214-827-8301
>http://ericneilsenphotography.com
Received on Sat Nov 19 20:33:21 2005