High voltage insulation / potting resins. - UK Vintage Radio Repair and Restoration Discussion Forum

Kyle__B · 28th Oct 2020, 3:29 am

I've found myself in need of potting a diode put midway along a telly anode cable. Does anyone have any suggestions as far as resins/epoxies etc?

GMB · 28th Oct 2020, 11:05 am

I once potted a tripler using silicone sealant - the non-acidic kind (I think called low modulus ?maybe). It worked very well and has the useful feature that it is not so hard to unpot it if needed.

wave solder · 28th Oct 2020, 11:13 am

I potted a tripler in my Tek scope using the non acidic silicone sealant about 10 years ago and it's still working fine.

GrimJosef · 28th Oct 2020, 11:14 am

I'd support the recommendation of a flexible potting compound. The posh stuff would be something like this https://uk.farnell.com/acc-silicones...ure/dp/8497494.

Cheers,

GJ

Lloyd 1985 · 28th Oct 2020, 2:10 pm

We have some stuff at work that should be good for this sort of thing, will be worth checking the datasheet first though, it’s Dow Corning RTV 3140, a flowable silicone sealant, it’s non acidic and suitable for electronics, but does take a long time to cure if you use a lot of it. It’s quite expensive, but a look on eBay should yield a tube that has passed its sell by date for not very much! We find that it’s still good for quite some time after it’s passed it’s use by date! There is also a non flowable version 3145 if you don’t want it to move from where you put it!

Regards
Lloyd

28th Oct 2020, 3:29 am	#1
Kyle__B Banned Join Date: Mar 2020 Location: Nijmegen, Netherlands Posts: 142	High voltage insulation / potting resins. I've found myself in need of potting a diode put midway along a telly anode cable. Does anyone have any suggestions as far as resins/epoxies etc?

28th Oct 2020, 11:05 am	#2
GMB Dekatron Join Date: Aug 2003 Location: near Reading (and sometimes Torquay) Posts: 3,098	Re: High voltage insulation / potting resins. I once potted a tripler using silicone sealant - the non-acidic kind (I think called low modulus ?maybe). It worked very well and has the useful feature that it is not so hard to unpot it if needed.

28th Oct 2020, 11:13 am	#3
wave solder Hexode Join Date: Feb 2007 Location: Chesterfield, Derbyshire, UK. Posts: 483	Re: High voltage insulation / potting resins. I potted a tripler in my Tek scope using the non acidic silicone sealant about 10 years ago and it's still working fine.

28th Oct 2020, 11:14 am	#4
GrimJosef Dekatron Join Date: Sep 2007 Location: Oxfordshire, UK. Posts: 4,311	Re: High voltage insulation / potting resins. I'd support the recommendation of a flexible potting compound. The posh stuff would be something like this https://uk.farnell.com/acc-silicones...ure/dp/8497494. Cheers, GJ __________________ http://www.ampregen.com

28th Oct 2020, 2:10 pm	#5
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,820	Re: High voltage insulation / potting resins. We have some stuff at work that should be good for this sort of thing, will be worth checking the datasheet first though, it’s Dow Corning RTV 3140, a flowable silicone sealant, it’s non acidic and suitable for electronics, but does take a long time to cure if you use a lot of it. It’s quite expensive, but a look on eBay should yield a tube that has passed its sell by date for not very much! We find that it’s still good for quite some time after it’s passed it’s use by date! There is also a non flowable version 3145 if you don’t want it to move from where you put it! Regards Lloyd