Fish out of water

Hi all, my name's sean, and I'm a scientific glassblower, not a model engineer. I'm here to ask for a favour, but more about that elsewhere. Meanwhile, if anyone needs small, fiddly glass stuff, give me a shout

Sean

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Very interesting occupation Sean !!

You are very welcome, and your generous offer is noted.

MichaelG.

Welcome Sean,

Not heard of that skill before but I can guess what it entails, some skill, offer duly noted, will be glad to help where possible.

George.

Thanks George,

If you do a google image search for 'scientific glassblower' you'll see the kind of work I do - although most of those guys are a lot more experienced than me!

Sean

A real skill, watched a TV programme a bit ago on a female laboratory glass maker/blower and it was absolutely fascinating what she could do. Never seen or heard of a glass lathe before then, a lovely piece of kit.

Mick, that would have been Gayle, I think - she had a spot on the One Show, I think it was. There are not many scientific glassblowers in the UK, so we pretty much know, or at least know of, each other, via the British Society of Scientific Glassblowers. They have a website, which I administer, at bssg.co.uk

.

Thanks, Sean

**LINK**

MichaelG.

I would have thought there was a ready market hereabouts for klein bottles, handy for keeping all sorts of things in........

Hi Sean, welcome to the forum. It's nice to have another expert to quiz!

I wonder if you recognise the pictures of this mercury timer switch as being the work of a scientific glass blower?

It's about 80mm long, the pip end tube is 21.25mm diameter and the other, lower, end is about 19.75mm diameter. The lower end is flat, but the whole assembly tilts 10 degrees towards the electrodes.

Inverting the assembly causes the mercury to pass into the other chamber through a large inner tube (about 8mm i/d). When the switch is returned to the normal position, mercury drips into the lower chamber through a pinch tube, taking about 25 seconds to drain back. During that 25 seconds the mercury makes the switch by shorting two electrodes in the top chamber.

I have 3 of them and have often wondered if they were hand made and what they were used for. Something that rotates and waits for 25 seconds before repeating I guess.

The design and construction are ingenious. If this is what you do, I'm impressed!

Regards,

Dave

Welcome Sean,

Now we know who to call for props for Dr Frank N. Furter's laboratory

Neil

Hi Dave,

Yes, those will definitely be handmade - they look pretty 'historic' - certainly not something we would need to make these days. Very neat design, though! They will have been calibrated by repeatedly timing the return loop flow, and constricting a bit by warming the loop at the midpoint. Plainly part of a tip-delay circuit of some sort, but no idea whatsoever what it might be. Very interesting!

Sean

Welcome Sean,

something I watched in action about 25 tears ago

**LINK**

a mercury arc rectifier

John

Edited By john swift 1 on 12/01/2016 13:57:57

Hi all

we used to use a similar mercury arc rectifier to control the spot welding times on cars produced a Dagenhamin the 70ty s (Mk3 cortina)

When I worked at the Philips Research Labs, Redhill, in the early seventies we had a glass shop with a number of scientific glass blowers. Some of the things they turned out looked impossible to me. They always gave impressive demonstrations on open days.

Sadly all gone now.

Russell.

Edited By Russell Eberhardt on 12/01/2016 19:47:52

Thanks for satisfying my curiosity Sean.

I bought the switches for the mercury at a Radio Rally during the 90's. But I decided to keep them intact when I realised how beautifully they'd been made. If they're historic I might ask the Antiques Road Show what they're worth!

Not quite so much sparky fun as a power rectifier, but I wanted to use the mercury to make a replica of an "Italian Navy Coherer". This was an early type of wireless detector consisting of a spinning disc with a sharp edge rotating in a thin layer of oil floating on mercury. The oil insulated the disc from the mercury unless a radio signal was present. I never made one!

Cheers,

Dave

Sadly, I doubt they'd be worth anything - and you might even be charged for safe disposal! But yes, very interesting, even though not as jazzy as that rectifier thingy - that's a bit of a beast...

You'll fit in well here.

Yeah, I've often looked at that video, and weighed my chances....
One day.

Go on... you KNOW you really want to

I remember making pipettes for my Thomas Slater chemistry sets from soda glass tubing, back in the day. Perhaps you might be persuaded to write a short article for MEW on basic glasswork that could be handy in the workshop - just raw beginners stuff.

Neil