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14th Sep 2006, 3:23 pm | #1 |
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EHT Electrical Insulating Resin or similar
Does anyone know of any kind of electrical insulating resin that could be used to repair broken terminals on EHT transformers and the like which could be used to repair breaks/damage in the original insulation?
The nearest reference I have been able to find is this: http://www.pitchcare.com/shop/product.php?id=3709 But this doesn't look quite right. I've tried Araldite but it does not seem to insulate EHT voltages, so any suggestions greatly appreciated. Any substance which sets hard and will insulate would do the job. Many thanks. Peter. |
14th Sep 2006, 3:45 pm | #2 |
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Re: EHT Electrical Insulating Resin or similar
Sorry, but I can't hep you on that - but I must ask - since "Araldite" immediately sprung to mind before I reached the end of your Post - in what way does the Araldite fail? Arcing over within? Catastophic insulation failure? Catching fire? Mechanical disintegration? Or?
I ask this because I would have used Araldite without any hesitation whatsoever! So, I need to learn - and, hopefully save myself a big headache one day! Al. |
14th Sep 2006, 4:55 pm | #3 |
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Re: EHT Electrical Insulating Resin or similar
Well I thought pretty much the same as you in this, but Araldite seemed to act like a conductor rather than an insulator, it made me wonder what exactly it's made from? The arcing increased with Araldite, so it would seem that, when you're talking EHT type voltages Araldite is perhaps not a good insulator?
Any other suggestions greatly appreciated. |
14th Sep 2006, 5:18 pm | #4 |
Dekatron
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Re: EHT Electrical Insulating Resin or similar
Hi Peter,
I would suggest potting compound - available from RS, or black silicone sealant (the stuff without acetic acid) - I have used both at up to 3000v and they appear to be ok..... Cheers Sean
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14th Sep 2006, 5:45 pm | #5 | |
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Re: EHT Electrical Insulating Resin or similar
Quote:
If solidity is not an issue then silicone rubber "bath seal" definitely works, but again you have to use the right kind, which I think is the one called "low modulus" - anyway, it's the one that does NOT smell of acetic acid. I used it to pot a 10kV multiplier which would not work in the air at all. |
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14th Sep 2006, 5:51 pm | #6 |
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Re: EHT Electrical Insulating Resin or similar
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14th Sep 2006, 5:56 pm | #7 | |
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Re: EHT Electrical Insulating Resin or similar
Quote:
Was the arcing inside the Araldite, or running along its surface? Were there cracks in the Araldite or other forms of mechanical deterioration visible? There are many types of Araldite available. What one did you use? Al. |
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14th Sep 2006, 6:04 pm | #8 |
Nonode
Join Date: Feb 2005
Location: Worcestershire, UK.
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Re: EHT Electrical Insulating Resin or similar
Did you clean all traces of charring or dirt from the area before adding the Araldite?
Once spotlessly clean, have you sprayed the area with an anti-corona insulating lacquer? Steve |
14th Sep 2006, 9:49 pm | #9 |
Heptode
Join Date: Jul 2003
Location: North Walsham, Norfolk, UK.
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Re: EHT Electrical Insulating Resin or similar
When I was younger and short of dosh, I used to mend Grundig green triplers with Araldite.
Quite a few sets were done with this and only one fire! This was put out and a new tripler fitted. Not to be done now though - COSHH, BEAB, etc. 24kv was the voltage so it should be OK. Danny |
14th Sep 2006, 10:02 pm | #10 |
Retired Dormant Member
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Re: EHT Electrical Insulating Resin or similar
Notice that Araldite may not be suitable in high-temperature applications. The common types softens at relatively low temperatures.
Frank N. |