Heavy fabric sticky tape on transformer - UK Vintage Radio Repair and Restoration Discussion Forum

ChrisThomas · 23rd Nov 2020, 6:34 pm

I'm working away reassembling my old Bush radio. There's a heavy fabric sticky tape on the transformer, which, I assume, is heat resistant or similar. A piece has come off the side with the wiring connections to the rectifier circuit. Having lost its stickiness with age, it's not staying in place. Please can anyone advise what tape I should replace this with? Many thanks!
Chris

kalee20 · 23rd Nov 2020, 11:59 pm

Photo would help!

These days... Glass cloth tape, 3M type 69 or 79 (same fabric, different adhesives) will be good to 155 or 180 deg C. Available from RS, ISTR... And very likely eBay search will find.

Diabolical Artificer · 24th Nov 2020, 8:00 am

You could use Kapton tape to seal it back together,about a fiver a roll on ebay. You do have to go all the way round the bobbin/winding though so it can stick to itself. I've tried to patch a few similar tfmrs by taping most of the way round, doesn't last long.

Andy.

ChrisThomas · 24th Nov 2020, 11:16 am

Many thanks for the replies and advice on suitable tapes...apologies for the lack of a picture - should have done that...
Chris

ChrisThomas · 24th Nov 2020, 1:34 pm

Here's a couple of pictures of the transformer and the tape...the tape still wrapping the sides of the transformer is what still sticks - I haven't disturbed this unnecessarily...
Chris

Refugee · 24th Nov 2020, 2:17 pm

That looks more like common "gaffer" tape than anything else I know of.
It is not obvious why it has been added to the outside of the clamp.
Perhaps it is there as a cosmetic cover for the drop wires from the tags to the ends of the windings.

kalee20 · 24th Nov 2020, 2:18 pm

That looks as much like black gaffer tape as anything! Can't see the purpose.

Having said that, you won't go wrong replacing it with glass cloth tape, acrylic adhesive (not as high-temperature as silicone adhesive, but sticks better).

Kapton tape, as Andy suggested, has great properties, excellent temperature capabilities. But adhesive used is silicone based, so as not to compromise the high-temperature performance, and it's not good except to a really smooth surface such as itself - again as Andy said.

ChrisThomas · 24th Nov 2020, 6:20 pm

Thanks folks... It doesn't look very special tape to me, either! Certainly tears easily enough...

Diabolical Artificer · 27th Nov 2020, 7:19 am

That tfmr looks like it's been rewound or to secure the tag board and the tape outside the bobbin put there to stop shorts from the connecting wiring. BTW the or/blu wiring looks very long, needlessly so. If 240v mains goes through it it'll be chucking out EMI if heater maybe dropping voltage and EMI, might be worth sorting.

Andy.

23rd Nov 2020, 6:34 pm	#1
ChrisThomas Triode Join Date: Oct 2020 Location: Tranent, East Lothian, Scotland, UK. Posts: 17	Heavy fabric sticky tape on transformer I'm working away reassembling my old Bush radio. There's a heavy fabric sticky tape on the transformer, which, I assume, is heat resistant or similar. A piece has come off the side with the wiring connections to the rectifier circuit. Having lost its stickiness with age, it's not staying in place. Please can anyone advise what tape I should replace this with? Many thanks! Chris

23rd Nov 2020, 11:59 pm	#2
kalee20 Dekatron Join Date: Feb 2007 Location: Lynton, N. Devon, UK. Posts: 7,079	Re: Heavy fabric sticky tape on transformer Photo would help! These days... Glass cloth tape, 3M type 69 or 79 (same fabric, different adhesives) will be good to 155 or 180 deg C. Available from RS, ISTR... And very likely eBay search will find.

24th Nov 2020, 8:00 am	#3
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,657	Re: Heavy fabric sticky tape on transformer You could use Kapton tape to seal it back together,about a fiver a roll on ebay. You do have to go all the way round the bobbin/winding though so it can stick to itself. I've tried to patch a few similar tfmrs by taping most of the way round, doesn't last long. Andy. __________________ Curiosity hasn't killed this cat...so far.

24th Nov 2020, 11:16 am	#4
ChrisThomas Triode Join Date: Oct 2020 Location: Tranent, East Lothian, Scotland, UK. Posts: 17	Re: Heavy fabric sticky tape on transformer Many thanks for the replies and advice on suitable tapes...apologies for the lack of a picture - should have done that... Chris

24th Nov 2020, 1:34 pm	#5
ChrisThomas Triode Join Date: Oct 2020 Location: Tranent, East Lothian, Scotland, UK. Posts: 17	Re: Heavy fabric sticky tape on transformer Here's a couple of pictures of the transformer and the tape...the tape still wrapping the sides of the transformer is what still sticks - I haven't disturbed this unnecessarily... Chris Attached Thumbnails

24th Nov 2020, 2:17 pm	#6
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,553	Re: Heavy fabric sticky tape on transformer That looks more like common "gaffer" tape than anything else I know of. It is not obvious why it has been added to the outside of the clamp. Perhaps it is there as a cosmetic cover for the drop wires from the tags to the ends of the windings.

24th Nov 2020, 2:18 pm	#7
kalee20 Dekatron Join Date: Feb 2007 Location: Lynton, N. Devon, UK. Posts: 7,079	Re: Heavy fabric sticky tape on transformer That looks as much like black gaffer tape as anything! Can't see the purpose. Having said that, you won't go wrong replacing it with glass cloth tape, acrylic adhesive (not as high-temperature as silicone adhesive, but sticks better). Kapton tape, as Andy suggested, has great properties, excellent temperature capabilities. But adhesive used is silicone based, so as not to compromise the high-temperature performance, and it's not good except to a really smooth surface such as itself - again as Andy said.

24th Nov 2020, 6:20 pm	#8
ChrisThomas Triode Join Date: Oct 2020 Location: Tranent, East Lothian, Scotland, UK. Posts: 17	Re: Heavy fabric sticky tape on transformer Thanks folks... It doesn't look very special tape to me, either! Certainly tears easily enough...

27th Nov 2020, 7:19 am	#9
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,657	Re: Heavy fabric sticky tape on transformer That tfmr looks like it's been rewound or to secure the tag board and the tape outside the bobbin put there to stop shorts from the connecting wiring. BTW the or/blu wiring looks very long, needlessly so. If 240v mains goes through it it'll be chucking out EMI if heater maybe dropping voltage and EMI, might be worth sorting. Andy. __________________ Curiosity hasn't killed this cat...so far.