Mercury Arc Rectifier? Where to start - Page 3 - UK Vintage Radio Repair and Restoration Discussion Forum

threeseven · 28th Nov 2016, 8:14 pm

Yes, it must be fate!

kalee20 · 28th Nov 2016, 8:52 pm

I'd honestly have thought that a small cinema rectifier set would be the best hope, capable of supplying 50A at 40V or so for the arc lamps. Still haven't any idea where to pick one from, but maybe a cinema projectionists forum might yield a result.

Couple of names spring to mind - Les Castree, and Jack Roe. Which a google search may find.

Bearing in mind that MAR's contain a sizeable amount of mercury, I can imagine a lot of decommissioned rectifier bulbs being opened to recover the metal. It's not exactly cheap stuff!

kalee20 · 28th Nov 2016, 8:57 pm

Ooh! Just seen the listing. Suggest make contact quick with the seller, in case ebay pull it. I think they have rules about mercury-containing items! If they do, you'd want to stay in touch!

The Philpott · 28th Nov 2016, 9:29 pm

Coincidences will always happen, the laws of chance dictate it, but......Hmm!

I hope this goes to the right person- ie S1997.

Lucien Nunes · 28th Nov 2016, 9:32 pm

There was a time when bulbs were routinely smashed to obtain mercury, however the world demand for it is reducing, due to such measures as the RoHS directive and the ever smaller amounts used per fluorescent tube. The percentage recovered from industrial uses has improved and is providing a greater fraction of demand, so prices have fallen. Given the tighter supervision of hazardous substances in the workplace, it is unlikely that many bulbs now get broken for mercury. An industrial site that has unwanted bulbs now has to pay to have them removed and reprocessed, in order to provide the paper-trail. Unless of course they realise that bulbs are not necessarily hazardous waste, but pieces of equipment that still have a use and can be sold as a going concern, albeit for rather modest sums.

kalee20 · 28th Nov 2016, 9:43 pm

It's a single phase jobbie too, easier to get up and running than a 3-phase! And easier to turn back upright too, so the mercury runs in the wide gaps between the electrodes and not into the arms!

Lucien Nunes · 28th Nov 2016, 9:50 pm

I think we should not discuss items that are the subject of live auctions. In the general case I would say that a Hewittic 100/2 single-phase full-wave 100A bulb with straight arms would probably have been used in a unit-type cinema rectifier (serving one projector) or battery charger.

We have the Nevelin equivalent in the dining room. Her name is Katie and if you are very nice and I get a few minutes I will make a short video showing her alight and how her control gear works etc.

Steph1997 · 28th Nov 2016, 10:06 pm

Quote:

Originally Posted by threeseven

STEPH!!! The object of your desire has just appeared on ebay, and IT IS IN DERBY!!!

http://www.ebay.co.uk/itm/RARE-Mercu...oAAOSw-0xYPBLu

Gahh! My hearts dancing!

I have messaged someone about one similar!
I think if everthing all goes well I'll be collecting one tomorrow evening!
I'll keep you all updated

Regards,
Steph

Herald1360 · 29th Nov 2016, 12:14 am

You might need a lot of desire to win it, though.

Thyristor · 29th Nov 2016, 12:23 am

Good luck, these devices have long fascinated me.

Where to start; I would say very carefully.....

high_vacuum_house · 29th Nov 2016, 9:12 am

Good morning,
Just my 2 penneth worth but as it is loose in a box I personally would make a cabinet type enclosure to fit the MAR as soon as possible to protect any accidental damage to the arms if it were to get knocked (i.e. vacuum cleaner, clumsy cat ECT.). Also to have it the correct way up so the mercury cannot slosh around too much!! Good luck

Christopher Capener

Lucien Nunes · 29th Nov 2016, 10:13 am

It's fine for the mercury to slosh around the bulb, which is strong by virtue of its shape and has no projecting surfaces for the mercury to strike. What is risky is allowing any slosh into the arms, where the near-vacuum provides no cushioning against mercury hitting the anode or closed end. A solid plug of mercury entering the arm can easily break it as it strikes the end like a slide hammer. Hence, bulbs are normally handled and shipped upside down, and only righted during final installation. This can be an intricate process on large bulbs, as the mercury has to be decanted into and out of the arms by a 'screw' motion.

Steph1997 · 29th Nov 2016, 10:16 am

Quote:

Originally Posted by high_vacuum_house

Just my 2 penneth worth but as it is loose in a box I personally would make a cabinet type enclosure to fit the MAR as soon as possible to protect any accidental damage to the arms if it were to get knocked (i.e. vacuum cleaner, clumsy cat ECT.).

I have a cabinet built in my wall so my plan for the mean time i's to strip everything out, make or buy a stand, then perspex the door and maybe put LED's the bottom of the cabinet in for now until I find the rest, it'l be safe and locked away for viewing and not touching until I can buy an original case.

We'll see, my hopes are up but the guys not messaged me back yet <\3

I'll keep you all updated!
Thanks
Steph

Steph1997 · 30th Nov 2016, 9:15 pm

*****UPDATE*****
Everybody Look!!!
My precious!!<3
Steph

TonyDuell · 30th Nov 2016, 9:21 pm

Well done!

Lloyd 1985 · 30th Nov 2016, 9:27 pm

Congratulations!

I always thought these things were bigger for some reason..?

Regards,
Lloyd.

Steph1997 · 30th Nov 2016, 9:35 pm

She's quite big bless her!

Regards
Steph

30th Nov 2016, 9:35 pm

What a splendid thing. Now is the time to get a mercury mop up kit (I think it is just a load a sulphur powder). Having this to hand will mean you won't break your precious.

30th Nov 2016, 9:37 pm

I can see your huge beaming smile through the bulb.

Steph1997 · 30th Nov 2016, 9:39 pm

Haha, I don't think I've stopped smiling!
I'm in love!

28th Nov 2016, 8:14 pm	#41
threeseven Octode Join Date: May 2010 Location: Worcestershire, UK. Posts: 1,880	Re: Mercury Arc Rectifier? Where to start Yes, it must be fate! __________________ BVWS member

28th Nov 2016, 8:52 pm	#42
kalee20 Dekatron Join Date: Feb 2007 Location: Lynton, N. Devon, UK. Posts: 7,077	Re: Mercury Arc Rectifier? Where to start I'd honestly have thought that a small cinema rectifier set would be the best hope, capable of supplying 50A at 40V or so for the arc lamps. Still haven't any idea where to pick one from, but maybe a cinema projectionists forum might yield a result. Couple of names spring to mind - Les Castree, and Jack Roe. Which a google search may find. Bearing in mind that MAR's contain a sizeable amount of mercury, I can imagine a lot of decommissioned rectifier bulbs being opened to recover the metal. It's not exactly cheap stuff!

28th Nov 2016, 8:57 pm	#43
kalee20 Dekatron Join Date: Feb 2007 Location: Lynton, N. Devon, UK. Posts: 7,077	Re: Mercury Arc Rectifier? Where to start Ooh! Just seen the listing. Suggest make contact quick with the seller, in case ebay pull it. I think they have rules about mercury-containing items! If they do, you'd want to stay in touch!

28th Nov 2016, 9:29 pm	#44
The Philpott Dekatron Join Date: Aug 2016 Location: Colchester, Essex, UK. Posts: 4,104	Re: Mercury Arc Rectifier? Where to start Coincidences will always happen, the laws of chance dictate it, but......Hmm! I hope this goes to the right person- ie S1997.

28th Nov 2016, 9:32 pm	#45
Lucien Nunes Rest in Peace Join Date: Apr 2008 Location: London, UK. Posts: 2,508	Re: Mercury Arc Rectifier? Where to start There was a time when bulbs were routinely smashed to obtain mercury, however the world demand for it is reducing, due to such measures as the RoHS directive and the ever smaller amounts used per fluorescent tube. The percentage recovered from industrial uses has improved and is providing a greater fraction of demand, so prices have fallen. Given the tighter supervision of hazardous substances in the workplace, it is unlikely that many bulbs now get broken for mercury. An industrial site that has unwanted bulbs now has to pay to have them removed and reprocessed, in order to provide the paper-trail. Unless of course they realise that bulbs are not necessarily hazardous waste, but pieces of equipment that still have a use and can be sold as a going concern, albeit for rather modest sums.

28th Nov 2016, 9:43 pm	#46
kalee20 Dekatron Join Date: Feb 2007 Location: Lynton, N. Devon, UK. Posts: 7,077	Re: Mercury Arc Rectifier? Where to start It's a single phase jobbie too, easier to get up and running than a 3-phase! And easier to turn back upright too, so the mercury runs in the wide gaps between the electrodes and not into the arms!

28th Nov 2016, 9:50 pm	#47
Lucien Nunes Rest in Peace Join Date: Apr 2008 Location: London, UK. Posts: 2,508	Re: Mercury Arc Rectifier? Where to start I think we should not discuss items that are the subject of live auctions. In the general case I would say that a Hewittic 100/2 single-phase full-wave 100A bulb with straight arms would probably have been used in a unit-type cinema rectifier (serving one projector) or battery charger. We have the Nevelin equivalent in the dining room. Her name is Katie and if you are very nice and I get a few minutes I will make a short video showing her alight and how her control gear works etc.

29th Nov 2016, 12:14 am	#49
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Mercury Arc Rectifier? Where to start You might need a lot of desire to win it, though. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

29th Nov 2016, 12:23 am	#50
Thyristor Pentode Join Date: May 2015 Location: Hove, East Sussex. Posts: 147	Re: Mercury Arc Rectifier? Where to start Good luck, these devices have long fascinated me. Where to start; I would say very carefully.....

29th Nov 2016, 9:12 am	#51
high_vacuum_house Octode Join Date: May 2003 Location: Belper Derbyshire Posts: 1,934	Re: Mercury Arc Rectifier? Where to start Good morning, Just my 2 penneth worth but as it is loose in a box I personally would make a cabinet type enclosure to fit the MAR as soon as possible to protect any accidental damage to the arms if it were to get knocked (i.e. vacuum cleaner, clumsy cat ECT.). Also to have it the correct way up so the mercury cannot slosh around too much!! Good luck Christopher Capener __________________ Interests in the collection and restoration of Tefifon players and 405 line television

29th Nov 2016, 10:13 am	#52
Lucien Nunes Rest in Peace Join Date: Apr 2008 Location: London, UK. Posts: 2,508	Re: Mercury Arc Rectifier? Where to start It's fine for the mercury to slosh around the bulb, which is strong by virtue of its shape and has no projecting surfaces for the mercury to strike. What is risky is allowing any slosh into the arms, where the near-vacuum provides no cushioning against mercury hitting the anode or closed end. A solid plug of mercury entering the arm can easily break it as it strikes the end like a slide hammer. Hence, bulbs are normally handled and shipped upside down, and only righted during final installation. This can be an intricate process on large bulbs, as the mercury has to be decanted into and out of the arms by a 'screw' motion.

30th Nov 2016, 9:15 pm	#54
Steph1997 Triode Join Date: Nov 2016 Location: Derby, Derbyshire, UK. Posts: 32	Re: Mercury Arc Rectifier? Where to start ***UPDATE*** Everybody Look!!! My precious!!<3 Steph Attached Thumbnails

30th Nov 2016, 9:21 pm	#55
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: Mercury Arc Rectifier? Where to start Well done!

30th Nov 2016, 9:27 pm	#56
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,817	Re: Mercury Arc Rectifier? Where to start Congratulations! I always thought these things were bigger for some reason..? Regards, Lloyd.

30th Nov 2016, 9:35 pm	#57
Steph1997 Triode Join Date: Nov 2016 Location: Derby, Derbyshire, UK. Posts: 32	Re: Mercury Arc Rectifier? Where to start She's quite big bless her! Regards Steph Attached Thumbnails

30th Nov 2016, 9:35 pm	#58
Guest Guest Posts: n/a	Re: Mercury Arc Rectifier? Where to start What a splendid thing. Now is the time to get a mercury mop up kit (I think it is just a load a sulphur powder). Having this to hand will mean you won't break your precious.

30th Nov 2016, 9:37 pm	#59
Guest Guest Posts: n/a	Re: Mercury Arc Rectifier? Where to start I can see your huge beaming smile through the bulb.

30th Nov 2016, 9:39 pm	#60
Steph1997 Triode Join Date: Nov 2016 Location: Derby, Derbyshire, UK. Posts: 32	Re: Mercury Arc Rectifier? Where to start Haha, I don't think I've stopped smiling! I'm in love!