UV tin scope detector

Started by Chaletgirl, November 10, 2015, 06:34:43 PM

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Chaletgirl

 ??? Does anyone know where I can purchase one of these other than rather expensively from the USA?  I have been working with reclaimed float glass from old houses and although the unpredictable effects can be interesting, I want to know what side I'm working on in future!  I have tried other ways of detecting tin from air side such as the water droplet test but I think the old glass  I'm working with is too compromised for that to work.
Thanks!

ajda

Do you need a special type for this?

You can get basic hand held UV lamps pretty cheap, eg - http://www.ebay.co.uk/itm/Ultra-violet-Portable-UV-Bank-Note-Checker-With-Torch-Lamp-Black-light-/281786881678?hash=item419bce968e:g:SMIAAOSwrklVCVE3

And this video shows a similar looking one for detecting the tin side - https://www.youtube.com/watch?v=HCiCnqkufEY
Alan
www.ajdalampwork.etsy.com

Zeldazog

I was given one of those bank note checkers by someone, it was only a cheap one and I am not convinced it was still working properly, but I couldn't detect a difference when I tried it. 

Then again, at that price, might be worth a try.

Chaletgirl, how old are we talking with glass from "old houses"?  Tin floated glass is only about 60 years old, and rolled glass was still in use in many places for a long time after it's invention/development.  It may not have a tin side.






Pat from Canvey

Thanks Allan and Dawn. That was interesting.

chas

I followed-up the links and was surprised to hear that "to avoid devit fire tin side up" on the video.

We follow something of a mantra here (subject to any special effect wanted) of "tin side down"...

The ebay note-checker is so cheap I've ordered a sacrificial one, will compare results with our conventional UV detector and report back. As Dawn suggests, I expect to find it doesn't work - something to do with the UV light spectrum created.

Finally, I am astonished at prices, and so not surprised Chaletgirl is hesitating to buy: UV now £170, Digital £205.

I thought they were dear at 70 quid 5 years ago and expected they'd be cheaper by now: let's all hope the banknote checker does work!

Chas



Zeldazog

Quote from: chas on November 16, 2015, 09:44:17 AM
I followed-up the links and was surprised to hear that "to avoid devit fire tin side up" on the video.

I always though that risked 'tin bloom' (the white cloudy effect to the initiated/lucky)? 

chas

#6
Quote from: Zeldazog on November 16, 2015, 09:56:43 AM
Quote from: chas on November 16, 2015, 09:44:17 AM
I followed-up the links and was surprised to hear that "to avoid devit fire tin side up" on the video.

I always though that risked 'tin bloom' (the white cloudy effect to the initiated/lucky)?  

s' been our experience Dawn...

Anyhow, back to the banknote checker:

it arrived this morning and I used it against a piece of 6mm with tin side clearly showing using the conventional detector: nothing. You can't see any difference, side to side. It puts out a lot of 'surplus' light so I narrowed the aperture to a 4mm slit using black tape and tried that: nothing. Maddeningly, held against the edge of the glass, a wedge of cloudiness did show inside, but I couldn't tell which side that was on or nearest. I reduced the slit to a hole about 4mm x 6mm to cut out stray light further, but it had no effect. Even knowing which side was tin, I couldn't detect a difference on the surface of the glass.

So, banknote checker n/g then, at least the "Eagle Ultra Portable Bank Note Checker with Torch" isn't.
Sorry.

While I'm at it, and I think I raised this before but this thread has a relevance, we have had really disappointing devit results with St Gobain float glass - we make a point of specifying Pilkington's when ordering supplies.

Chas

Zeldazog

Quote from: chas on November 19, 2015, 10:48:11 AM
While I'm at it, and I think I raised this before but this thread has a relevance, we have had really disappointing devit results with St Gobain float glass - we make a point of specifying Pilkington's when ordering supplies.

Interesting.  I usually got off-cuts (for free of course  ;D) or went skip diving occasionally, so I never knew what I was getting.

If I am buying, I get greenhouse/horticultural glass - it has no tin side (as it's rolled), so it is not an issue.  Of course, it does only come in 3mm thickness, no other, but at £3 a sheet 2ft square, that will do me  ;D


chas

Quote from: Zeldazog on November 19, 2015, 12:43:34 PM

If I am buying, I get greenhouse/horticultural glass - it has no tin side (as it's rolled), so it is not an issue.  Of course, it does only come in 3mm thickness, no other, but at £3 a sheet 2ft square, that will do me  ;D



You've given me that tip before Dawn, 600x600 for £3 is a bargain and it's regrettable I've never remembered to order some in to try ourselves, particularly as I've been told 3mm float is dearer than 4mm float "being less commonly used" - £20.70m2 against £15.76m2

Our rationale has been that we issue 3mm to students as it's easy to cut and because we have to bang on about tin side on the 2,4 and 6mm we commonly use (and also have on the bench) we've come to  the conclusion we might confuse the issue if we reveal to them that they don't have to bother tin-siding 3mm, sometimes...

Cheers,

Chas

Chaletgirl

Firstly, thanks everyone for your information.  I was hoping for a cheap result from the note checker!  Never mind.  A tin scope detector may have to wait until my next visit to the States as I find tools are a little cheaper there.
Re your question about the age of my glass.  Some of it is from my house which was built in 1916 - very varied results.  Other stuff is from skips or people just give it to me (fortunately) rather than take it to the tip when they know I will make use of it.  So I don't always know what vintage it might be.
Since my last  post I have been using old greenhouse glass and getting much better and clear results so maybe I'll stick to that for a while as I have a large supply. :) :)