Farnell bench PSU strangeness! - UK Vintage Radio Repair and Restoration Discussion Forum

threeseven · 17th Mar 2014, 7:25 pm

Recently I bought a Farnell C1 bench psu, 0-50V at upto 1A. It's faulty, which I knew about. Just removed the top cover and found something strange and which I've never seen the like of before. All around the flanges of the chassis which form the attachment to the top covers sides and top there is a deliberately applied coating of what looks and smells like Linseed oil!
Some of it has dripped onto one of the PCB's. It's quite nasty to deal with as it tends to be wherever i put my fingers! Also the top cover has been painted black over the original blue.
Obviously I'll be removing it but it's a total mystery why anyone would do this

Anyone care to offer an explanation?

woodchips · 17th Mar 2014, 7:28 pm

Paper capacitor exploded?

threeseven · 17th Mar 2014, 7:37 pm

No, whatever the substance is, and I'm quite certain it is linseed oil, it has been deliberately applied.

Radio Wrangler · 17th Mar 2014, 7:53 pm

Can't think of anything that would degrade into linseed oil. And if it isn't in places explicable by a spill from above, well that just leaves the strange religious rite as the only possible answer.

DAvid

G0HZU_JMR · 17th Mar 2014, 9:53 pm

I think it can be used to repel water once it sets so maybe this was someone's pet way to stop corrosion?

Just be grateful you didn't also buy a car from the same person

turretslug · 17th Mar 2014, 10:06 pm

I was once given a nice simple, 10MHz double beam (emphasis double beam, not dual trace!) Philips scope from the 24V option era that had been rescued from the skip, naturally I opened it up just to check before powering it- it was absolutely swimming with green oil that had all the look and aroma of Duckhams, the scope didn't actually have many large openings/crevices in it, so I was puzzled as to how it was so sodden internally. It actually cleaned up quite well quite quickly and worked fine, not even any noticeable switch problems- though I always bore in mind that it could represent a fire hazard and didn't leave it on unattended. I told the guy who gave it to me that it appeared to have been immersed in engine oil, he laughed and confessed that it was from the MT yard at Chobham.

Alistair D · 17th Mar 2014, 10:31 pm

You need to read this article before cleaning up the mess. No it is not a joke.

http://www.esfrs.org/blackmuseum/linseedOilRags.shtml

Al

threeseven · 17th Mar 2014, 10:59 pm

Thanks for that Al, I had forgotten about that phenomena. There isn't all that much on this supply and what I have wiped off is now in the bin outside. I'm thinking that this may have once been a spill on top of the supply and found it's way to the flange joins by capillary action. Any surplus on top would have been wiped up at the time. There is some on the bottom cover too, so it would seem to support this possibility.

17th Mar 2014, 7:25 pm	#1
threeseven Octode Join Date: May 2010 Location: Worcestershire, UK. Posts: 1,880	Farnell bench PSU strangeness! Recently I bought a Farnell C1 bench psu, 0-50V at upto 1A. It's faulty, which I knew about. Just removed the top cover and found something strange and which I've never seen the like of before. All around the flanges of the chassis which form the attachment to the top covers sides and top there is a deliberately applied coating of what looks and smells like Linseed oil! Some of it has dripped onto one of the PCB's. It's quite nasty to deal with as it tends to be wherever i put my fingers! Also the top cover has been painted black over the original blue. Obviously I'll be removing it but it's a total mystery why anyone would do this Anyone care to offer an explanation? __________________ BVWS member

17th Mar 2014, 7:28 pm	#2
woodchips Octode Join Date: May 2010 Location: Grantham, Lincolnshire, UK. Posts: 1,175	Re: Farnell bench PSU strangeness! Paper capacitor exploded?

17th Mar 2014, 7:37 pm	#3
threeseven Octode Join Date: May 2010 Location: Worcestershire, UK. Posts: 1,880	Re: Farnell bench PSU strangeness! No, whatever the substance is, and I'm quite certain it is linseed oil, it has been deliberately applied. __________________ BVWS member

17th Mar 2014, 7:53 pm	#4
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,876	Re: Farnell bench PSU strangeness! Can't think of anything that would degrade into linseed oil. And if it isn't in places explicable by a spill from above, well that just leaves the strange religious rite as the only possible answer. DAvid __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

17th Mar 2014, 9:53 pm	#5
G0HZU_JMR Dekatron Join Date: Sep 2010 Location: Cheltenham, Gloucestershire, UK. Posts: 3,077	Re: Farnell bench PSU strangeness! I think it can be used to repel water once it sets so maybe this was someone's pet way to stop corrosion? Just be grateful you didn't also buy a car from the same person __________________ Regards, Jeremy G0HZU

17th Mar 2014, 10:06 pm	#6
turretslug Dekatron Join Date: Nov 2011 Location: Surrey, UK. Posts: 4,395	Re: Farnell bench PSU strangeness! I was once given a nice simple, 10MHz double beam (emphasis double beam, not dual trace!) Philips scope from the 24V option era that had been rescued from the skip, naturally I opened it up just to check before powering it- it was absolutely swimming with green oil that had all the look and aroma of Duckhams, the scope didn't actually have many large openings/crevices in it, so I was puzzled as to how it was so sodden internally. It actually cleaned up quite well quite quickly and worked fine, not even any noticeable switch problems- though I always bore in mind that it could represent a fire hazard and didn't leave it on unattended. I told the guy who gave it to me that it appeared to have been immersed in engine oil, he laughed and confessed that it was from the MT yard at Chobham.

17th Mar 2014, 10:31 pm	#7
Alistair D Nonode Join Date: Jan 2010 Location: Edinburgh, UK. Posts: 2,008	Re: Farnell bench PSU strangeness! You need to read this article before cleaning up the mess. No it is not a joke. http://www.esfrs.org/blackmuseum/linseedOilRags.shtml Al __________________ I won't tell you how I discovered that.

17th Mar 2014, 10:59 pm	#8
threeseven Octode Join Date: May 2010 Location: Worcestershire, UK. Posts: 1,880	Re: Farnell bench PSU strangeness! Thanks for that Al, I had forgotten about that phenomena. There isn't all that much on this supply and what I have wiped off is now in the bin outside. I'm thinking that this may have once been a spill on top of the supply and found it's way to the flange joins by capillary action. Any surplus on top would have been wiped up at the time. There is some on the bottom cover too, so it would seem to support this possibility. __________________ BVWS member