Over time,
PVC can lose its plasticiser and become stiff and very hard to work with and it doesn't need to be very hot inside a chassis to have an effect.
I use PTFE with silver plate copper or stranded copper with PTFE, the thing to remember is the fumes that "can come off" PTFE when its heated. So don't breath the fumes in.
I also use standard mains solid core with the PVC stripped and covered with PTFE sleeve.
If you bend PVC and solder it, it can split on the joint its a PITA..You can get round this by putting heat shrink over the ends before you solder.
Remember to use the correct solder for silver cables. The effect I have seen with silver going black and loosing connection (perhaps its a reaction) I don't know for sure but the effect is over a couple of years.
NB some PTFE cable is only rated at 600V so always check.
Regards
M. Gregg
PVC can lose its plasticiser and become stiff and very hard to work with and it doesn't need to be very hot inside a chassis to have an effect.
I use PTFE with silver plate copper or stranded copper with PTFE, the thing to remember is the fumes that "can come off" PTFE when its heated. So don't breath the fumes in.
I also use standard mains solid core with the PVC stripped and covered with PTFE sleeve.
If you bend PVC and solder it, it can split on the joint its a PITA..You can get round this by putting heat shrink over the ends before you solder.
Remember to use the correct solder for silver cables. The effect I have seen with silver going black and loosing connection (perhaps its a reaction) I don't know for sure but the effect is over a couple of years.
NB some PTFE cable is only rated at 600V so always check.
Regards
M. Gregg
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The blackening of silver is the forming of silveroxide, what has identical conduction as silver. Do you mean the metallurgic bond is ondone by the oxidation? Never had an issue with that (using Stannol with copper).
US military prohibits the use of Teflon insulated wire in military equipment. As Okcrum pointed out, Teflon flows under pressure. That's why Teflon tape is used for sealing pipe threads.
Here - take your choice.... not chea, though...
https://www.elfa.se/elfa3~eu_en/elfa/init.do?toc=20158&pageSize=10&filterClause=MANUFACTURER%3DHabia
and - BTW - I've made several hundred meters of twisted pairs.....just chuck in the jaws of a cordless and off you go....
https://www.elfa.se/elfa3~eu_en/elfa/init.do?toc=20158&pageSize=10&filterClause=MANUFACTURER%3DHabia
and - BTW - I've made several hundred meters of twisted pairs.....just chuck in the jaws of a cordless and off you go....
Rayfutrell, you sparked my interest, pardon the pun.
I hadn't realised PTFE and several other types of insulation are prohibited. Maybe for main wiring in aircraft etc. I'm sure it is still used in avionics, at least it was 20 odd years ago. Which is still after the banning.
Here is an interesting link:
Aircraft Electrical Wire Types by Alex Paterson
Anyway we used what was then Ersin Multicore 60/40 tin lead. Not even silver loaded and I have not seen a problem with it. Maybe the flux in another manufacturers solder affects the silver/copper? I would think that the higher melting point of silver loaded solder would pose a health risk with PTFE insulation. Polymer flu anyone?
Cheers
Matt.
I hadn't realised PTFE and several other types of insulation are prohibited. Maybe for main wiring in aircraft etc. I'm sure it is still used in avionics, at least it was 20 odd years ago. Which is still after the banning.
Here is an interesting link:
Aircraft Electrical Wire Types by Alex Paterson
Anyway we used what was then Ersin Multicore 60/40 tin lead. Not even silver loaded and I have not seen a problem with it. Maybe the flux in another manufacturers solder affects the silver/copper? I would think that the higher melting point of silver loaded solder would pose a health risk with PTFE insulation. Polymer flu anyone?
Cheers
Matt.
Interesting link there Matt,
PTFE is not regarded safe in aircraft..all amps are now linked to Apollo 13..😱
Its interesting how some solders erode the soldering iron tip..with the savbit solder the irons tip lasts.
There is also the whisker effect with some solders. (Off topic but interesting)
http://www.maximintegrated.com/en/app-notes/index.mvp/id/5250
Regards
M. Gregg
PTFE is not regarded safe in aircraft..all amps are now linked to Apollo 13..😱
Its interesting how some solders erode the soldering iron tip..with the savbit solder the irons tip lasts.
There is also the whisker effect with some solders. (Off topic but interesting)
http://www.maximintegrated.com/en/app-notes/index.mvp/id/5250
Regards
M. Gregg
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Excellent link M. Gregg,
I only skirted over it, ready for a propper perusal tomorrow😉
OT again but remember the old TO7 packaged transistors? Such as the AF117, for the time they were pretty special but they chose to tin plate the can. Which of course grew whiskers and ended the fun.
Cheers
Matt.
I only skirted over it, ready for a propper perusal tomorrow😉
OT again but remember the old TO7 packaged transistors? Such as the AF117, for the time they were pretty special but they chose to tin plate the can. Which of course grew whiskers and ended the fun.
Cheers
Matt.
Is teflon really suitable for soldering or even tube amp use? I'm not sure how hot it gets in there... but maybe not above 300C.
Polymer fume fever - Wikipedia, the free encyclopedia
Polymer fume fever - Wikipedia, the free encyclopedia
I only use PTFE cable,
You just have to be carful not to breath the fumes in when you solder..One of the things you have to watch out for is using Gas irons on large terminals.
When using red coloured PTFE and soldering you can see the PTFE turn dark red -Black as you heat the cable then it turns back to normal colour when it cools down. I am just a bit careful when I see the colour change.
And I turn my head when I breath in before I blow on any components to cool it.
You shouldn't breath in solder/flux fumes anyway but I am very careful
If I have to get close I hold my breath and step back before I breath in.
Its overkill but....
Keep the room ventilated..open a window..I also don't let my dog by me when I solder.
Normal operating temp should not be a problem..
Again your safety is up to you..Its always better to be aware!
Regards
M. Gregg
You just have to be carful not to breath the fumes in when you solder..One of the things you have to watch out for is using Gas irons on large terminals.
When using red coloured PTFE and soldering you can see the PTFE turn dark red -Black as you heat the cable then it turns back to normal colour when it cools down. I am just a bit careful when I see the colour change.
And I turn my head when I breath in before I blow on any components to cool it.
You shouldn't breath in solder/flux fumes anyway but I am very careful
If I have to get close I hold my breath and step back before I breath in.
Its overkill but....
Keep the room ventilated..open a window..I also don't let my dog by me when I solder.
Normal operating temp should not be a problem..
Again your safety is up to you..Its always better to be aware!
Regards
M. Gregg
Last edited:
One other item,
sometimes when you get a reel of Teflon cable it is covered in a white dust, I am carful when I see this, it could just be part of the manufacturing process, however I have seen the same "Dust" when Teflon cable is put in sleeving that is moved about on machinery. It seems when the cable rubs against other Teflon cables you get this dust. Its not a problem on your hands but if your the kind of person who rolls their own cigarettes and you get it in the tobacco and burn it...
I don't smoke but its worth remembering.
Regards
M. Gregg
sometimes when you get a reel of Teflon cable it is covered in a white dust, I am carful when I see this, it could just be part of the manufacturing process, however I have seen the same "Dust" when Teflon cable is put in sleeving that is moved about on machinery. It seems when the cable rubs against other Teflon cables you get this dust. Its not a problem on your hands but if your the kind of person who rolls their own cigarettes and you get it in the tobacco and burn it...
I don't smoke but its worth remembering.
Regards
M. Gregg
I could be wrong, but I believe the dust you are seeing is added to make the wire less slick and more mechanically manageable.
I have made harnesses and cleaned the cable before build and after a year the harness was full of white powder, and it was in lines between the cables (with rub marks). 😕
As you say the dust in the reels could be release agent<<as long as its not PTFE..
Look at the temperature inside a cigarette..
http://www.bat-science.com/groupms/sites/BAT_7AWFH3.nsf/vwPagesWebLive/DO858KZ6?opendocument&SKN=1
Regards
M. Gregg
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