Wet electrolytics....what's in them? - UK Vintage Radio Repair and Restoration Discussion Forum

Sideband · 3rd Oct 2005, 4:34 pm

I've been following the interesting thread on Visconol Capacitors and it has prompted me to ask a question about wet electrolytics. Does anybody know for sure what the liquid is that is in them? I have opened several of these in the past and carefully drained out the liquid into a plastic bag and simply rinsed the empty can out with meths. I seal the bag with the liquid in and put it out with the rubbish. Now is this liquid a PCB?

If so I will have to think again on the disposal of this stuff....it is only small amounts though.

Rich.

ppppenguin · 3rd Oct 2005, 4:42 pm

Definitely not a PCB. Quite possibly acid and corrosive but not really harmful to put out with your rubbish.

mickjjo · 3rd Oct 2005, 4:59 pm

Hi Rich, Re the liquid in wet electrolytics,

"The electrolyte is generally boric acid, or ammonium or sodium borate with a small amount of water in ethylene glycol, glycerin, dimethyl formamide or gamma-butryolactone."

.

Or so it says on this useful site:-

http://www.smecc.org/haz-mat_in_military_comm_.htm

Probably not too harmful, but difficult to spell....

.

Regards, Mick.

Sideband · 3rd Oct 2005, 10:16 pm

Thanks for that info guys.

As I recall, the liquid looked and acted like water so it's probably a mixture of things......didn't touch it to find out though!

I gather from that website that the PCB stuff is quite thick...like a thin treacle. Probably the same as the stuff used in those old Murphy line transformers. When I think of the number of those that were probably just thrown out with normal rubbish....!

Rich.

Station X · 3rd Oct 2005, 10:57 pm

The oil used in the bathtub capacitors in AR88 receivers smells like cooking oil to me, but I haven't tried using it for that purpose. I think these are paper capacitors immersed in oil. They are definitely not electrolytics. I just fit new polypropylene caps in the case.

Graham.

PWH · 4th Oct 2005, 5:21 pm

I have seen the corrosive effect on the aluminium cans the electrolyte has, once in contact with air. (Several exploded ones

)

I would not recommend getting it on your skin. I am sure it would be very irritating.

Roy Nichols · 2nd Nov 2005, 5:11 am

I don't want to speak out of turn but here in the US many old (pre-1979) oil filled capacitors all have PCB based oils in them as the dialectric. Since most of the old radios over here don't have any oil based caps the PCB disposal issue isn't much of a problem for radio collectors. It does pose a problem for those of us who collect vintage jukeboxes though. Most all Seeburgs from 1960 on up have a large PCB oil filled cap in them. In the earlier models it's in the Auto Speed Unit. In the later boxes it's right on the mechanism. When these caps leak they have a funny smell about them and an oily residue around the mountings. When handling these I always wear gloves and take the bad ones to the local household hazardous waste facility for proper disposal.

3rd Oct 2005, 4:34 pm	#1
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,572	Wet electrolytics....what's in them? I've been following the interesting thread on Visconol Capacitors and it has prompted me to ask a question about wet electrolytics. Does anybody know for sure what the liquid is that is in them? I have opened several of these in the past and carefully drained out the liquid into a plastic bag and simply rinsed the empty can out with meths. I seal the bag with the liquid in and put it out with the rubbish. Now is this liquid a PCB? If so I will have to think again on the disposal of this stuff....it is only small amounts though. Rich. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

3rd Oct 2005, 4:42 pm	#2
ppppenguin Retired Dormant Member Join Date: Dec 2003 Location: North London, UK. Posts: 6,168	Re: Wet electrolytics....what's in them? Definitely not a PCB. Quite possibly acid and corrosive but not really harmful to put out with your rubbish.

3rd Oct 2005, 4:59 pm	#3
mickjjo Rest in Peace Join Date: Jul 2004 Location: Dartford, Kent, UK. Posts: 1,661	Re: Wet electrolytics....what's in them? Hi Rich, Re the liquid in wet electrolytics, "The electrolyte is generally boric acid, or ammonium or sodium borate with a small amount of water in ethylene glycol, glycerin, dimethyl formamide or gamma-butryolactone." . Or so it says on this useful site:- http://www.smecc.org/haz-mat_in_military_comm_.htm Probably not too harmful, but difficult to spell.... . Regards, Mick.

3rd Oct 2005, 10:16 pm	#4
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,572	Re: Wet electrolytics....what's in them? Thanks for that info guys. As I recall, the liquid looked and acted like water so it's probably a mixture of things......didn't touch it to find out though! I gather from that website that the PCB stuff is quite thick...like a thin treacle. Probably the same as the stuff used in those old Murphy line transformers. When I think of the number of those that were probably just thrown out with normal rubbish....! Rich. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

3rd Oct 2005, 10:57 pm	#5
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Wet electrolytics....what's in them? The oil used in the bathtub capacitors in AR88 receivers smells like cooking oil to me, but I haven't tried using it for that purpose. I think these are paper capacitors immersed in oil. They are definitely not electrolytics. I just fit new polypropylene caps in the case. Graham.

4th Oct 2005, 5:21 pm	#6
PWH Heptode Join Date: Mar 2003 Location: Waiheke Island, New Zealand Posts: 503	Re: Wet electrolytics....what's in them? I have seen the corrosive effect on the aluminium cans the electrolyte has, once in contact with air. (Several exploded ones ) I would not recommend getting it on your skin. I am sure it would be very irritating.

2nd Nov 2005, 5:11 am	#7
Roy Nichols Triode Join Date: Oct 2005 Location: Grand Junction, Colorado, USA. Posts: 33	Re: Wet electrolytics....what's in them? I don't want to speak out of turn but here in the US many old (pre-1979) oil filled capacitors all have PCB based oils in them as the dialectric. Since most of the old radios over here don't have any oil based caps the PCB disposal issue isn't much of a problem for radio collectors. It does pose a problem for those of us who collect vintage jukeboxes though. Most all Seeburgs from 1960 on up have a large PCB oil filled cap in them. In the earlier models it's in the Auto Speed Unit. In the later boxes it's right on the mechanism. When these caps leak they have a funny smell about them and an oily residue around the mountings. When handling these I always wear gloves and take the bad ones to the local household hazardous waste facility for proper disposal. __________________ Regards, Roy