Another old Lyons Variac - UK Vintage Radio Repair and Restoration Discussion Forum

mark_in_manc · 12th Dec 2020, 8:38 pm

I was rooting through a bin the other day (looking for bearings for an enormous 1920s stationary diesel engine - it was quite an exciting bin) and this poor thing emerged. It's older I think than the other ones I have - rather than the frame pieces being cast alloy, these are brass with a crinkle-black finish, and the enclosure is nicely made of quite heavy gauge steel perf. It was *very* rusty and dirty and *very* seized (the Bakelite tube through the middle was swollen, as usual). I spent a couple of hours gently coaxing it apart.

The scale plate is upside-down in the main picture - I cleaned off some of the thick green verdigris and there was nothing there. The top side was even worse, but by gently rubbing away, eventually a genie / no sorry, eventually letters appeared and you can see what I ended up with. I don't think the other ones I have, have an embossed brass scale plate, either. Not sure what I'll do here - I suppose I could spray it and then try to rub back through to the high-spot embossed lettering. Anyone tried that kind of thing?

My girls have watched too many kids sci-fi programs. When the younger saw the coil (which has continuity

and is now clean and dry) she reckoned it ought to be issuing a massive stream of blue light, and if it was turned off the universe would end. I think she's going to find the reality of twisting the little steering wheel a bit of a let-down

Goldie99 · 13th Dec 2020, 12:35 pm

Quote:

Originally Posted by mark_in_manc

Not sure what I'll do here - I suppose I could spray it and then try to rub back through to the high-spot embossed lettering. Anyone tried that kind of thing?

I used that technique a couple of years ago for some speaker name plates. In that case, they were Aluminium with slightly raised lettering, but with a thin coat of satin black, and gently rubbing back, the results were very good - I fixed some fine wet & dry on a surface plate, and rubbed the plates on it, so the flatter the part the better. If it's 'dished', or been bent, it'll make it much more difficult.

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Alan

mark_in_manc · 13th Dec 2020, 3:04 pm

That came out really well Alan. My plate is a bit dished, and my letters are only raised a thou or two (I was conscious of not polishing them off altogether as I was cleaning). I think it might be best left alone, but we'll see. There's a spare plate off a later Variac on ebay at the moment, but where's the fun in that (and buying it will blow the budget

)

mark_in_manc · 27th Jan 2021, 2:35 pm

Here's the finished thing, nicely finished off with a brown 13A socket from Hugh. Thanks Hugh! The brushes are on their last legs, but (anisotropic graphite not withstanding) I'll have a go with some bits of angle grinder brush when they give up entirely.
cheers
Mark

Nickthedentist · 27th Jan 2021, 2:46 pm

Well done, Mark, that looks beautiful.

Just the thing to keep the wife amused in the kitchen!

Keep up the good work,

N.

The Philpott · 27th Jan 2021, 2:53 pm

Looks like the scale plate also has dezincification, separation of the copper and zinc, can make things fragile if it's advanced. Interesting that it seems to be marked up in %, and has no 'overwinding'- i'm sure some that i've seen can give around 270v from 240v input..?

Dave

ajgriff · 27th Jan 2021, 3:21 pm

Quote:

Originally Posted by mark_in_manc

The brushes are on their last legs, but (anisotropic graphite not withstanding) I'll have a go with some bits of angle grinder brush when they give up entirely.

Worth considering modifying these when the time comes:

https://uk.rs-online.com/web/p/variacs/8902897/

RS do larger sizes too. Worked well on my Lyons Variac.

Alan

mark_in_manc · 27th Jan 2021, 6:28 pm

Hey, they’re nice and cheap. If I’m ever back in work I’ll sneak a couple onto an order.
Thanks
Mark

edit - and yes, this is a 100L which apparently only went up to the supply voltage and not beyond. Hey, it’s a gift-horse

Stockden · 28th Jan 2021, 9:45 am

That looks great Mark. Like most of my ‘junk’ I’ve carried that socket round the world (well round Europe anyway) for decades. It’s good to see it put to use at last!

Hugh

The Philpott · 28th Jan 2021, 11:48 am

- and it's got the military mark so the variac gets an upgrade!

John_Dw · 28th Jan 2021, 12:24 pm

Nice job, I do like to see old technology restored.

12th Dec 2020, 8:38 pm	#1
mark_in_manc Octode Join Date: Nov 2011 Location: Manchester, UK. Posts: 1,875	Another old Lyons Variac I was rooting through a bin the other day (looking for bearings for an enormous 1920s stationary diesel engine - it was quite an exciting bin) and this poor thing emerged. It's older I think than the other ones I have - rather than the frame pieces being cast alloy, these are brass with a crinkle-black finish, and the enclosure is nicely made of quite heavy gauge steel perf. It was very rusty and dirty and very seized (the Bakelite tube through the middle was swollen, as usual). I spent a couple of hours gently coaxing it apart. The scale plate is upside-down in the main picture - I cleaned off some of the thick green verdigris and there was nothing there. The top side was even worse, but by gently rubbing away, eventually a genie / no sorry, eventually letters appeared and you can see what I ended up with. I don't think the other ones I have, have an embossed brass scale plate, either. Not sure what I'll do here - I suppose I could spray it and then try to rub back through to the high-spot embossed lettering. Anyone tried that kind of thing? My girls have watched too many kids sci-fi programs. When the younger saw the coil (which has continuity and is now clean and dry) she reckoned it ought to be issuing a massive stream of blue light, and if it was turned off the universe would end. I think she's going to find the reality of twisting the little steering wheel a bit of a let-down Attached Thumbnails __________________ "The best dBs, come in 3s" - Woody Brown

13th Dec 2020, 3:04 pm	#3
mark_in_manc Octode Join Date: Nov 2011 Location: Manchester, UK. Posts: 1,875	Re: Another old Lyons Variac That came out really well Alan. My plate is a bit dished, and my letters are only raised a thou or two (I was conscious of not polishing them off altogether as I was cleaning). I think it might be best left alone, but we'll see. There's a spare plate off a later Variac on ebay at the moment, but where's the fun in that (and buying it will blow the budget ) __________________ "The best dBs, come in 3s" - Woody Brown

27th Jan 2021, 2:35 pm	#4
mark_in_manc Octode Join Date: Nov 2011 Location: Manchester, UK. Posts: 1,875	Re: Another old Lyons Variac Here's the finished thing, nicely finished off with a brown 13A socket from Hugh. Thanks Hugh! The brushes are on their last legs, but (anisotropic graphite not withstanding) I'll have a go with some bits of angle grinder brush when they give up entirely. cheers Mark Attached Thumbnails __________________ "The best dBs, come in 3s" - Woody Brown

27th Jan 2021, 2:46 pm	#5
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,864	Re: Another old Lyons Variac Well done, Mark, that looks beautiful. Just the thing to keep the wife amused in the kitchen! Keep up the good work, N.

27th Jan 2021, 2:53 pm	#6
The Philpott Dekatron Join Date: Aug 2016 Location: Colchester, Essex, UK. Posts: 4,108	Re: Another old Lyons Variac Looks like the scale plate also has dezincification, separation of the copper and zinc, can make things fragile if it's advanced. Interesting that it seems to be marked up in %, and has no 'overwinding'- i'm sure some that i've seen can give around 270v from 240v input..? Dave

27th Jan 2021, 6:28 pm	#8
mark_in_manc Octode Join Date: Nov 2011 Location: Manchester, UK. Posts: 1,875	Re: Another old Lyons Variac Hey, they’re nice and cheap. If I’m ever back in work I’ll sneak a couple onto an order. Thanks Mark edit - and yes, this is a 100L which apparently only went up to the supply voltage and not beyond. Hey, it’s a gift-horse __________________ "The best dBs, come in 3s" - Woody Brown

28th Jan 2021, 9:45 am	#9
Stockden Heptode Join Date: Mar 2008 Location: Forest of Dean, Gloucestershire, UK. Posts: 648	Re: Another old Lyons Variac That looks great Mark. Like most of my ‘junk’ I’ve carried that socket round the world (well round Europe anyway) for decades. It’s good to see it put to use at last! Hugh

28th Jan 2021, 11:48 am	#10
The Philpott Dekatron Join Date: Aug 2016 Location: Colchester, Essex, UK. Posts: 4,108	Re: Another old Lyons Variac - and it's got the military mark so the variac gets an upgrade!

28th Jan 2021, 12:24 pm	#11
John_Dw Tetrode Join Date: Dec 2020 Location: Stevenage, Hertfordshire, UK. Posts: 93	Re: Another old Lyons Variac Nice job, I do like to see old technology restored.