New Caps in old Cases - UK Vintage Radio Repair and Restoration Discussion Forum

MikeCross · 1st Feb 2019, 5:13 pm

I need to mount a new capacitor in an old capacitor case so that I can use its stud mounting facility.
Has anyone any advice on how to remove the old cap materials from its case and replace with the new cap. Are there any dangerous chemicals within capacitors?

AC/HL · 1st Feb 2019, 5:28 pm

If you put "restuffing" in the search box above you'll get a good idea of the techniques involved.

snowman_al · 1st Feb 2019, 5:54 pm

The answer of removal depends on the original construction.
Some are in a kind of wax. These tend to 'pull free' once the can is open if you drop them in near boiling water for a couple of minutes.
Most are in a pitch like material. You can heat them up too, but I find it easier to drill the centre out and 'unwind' the foil a bit at a time.
Older ones still have a fluid inside (likely borax) and just fall out.

Make sure you insulate the inside of the can before fitting everything back together.

I honestly do not know if any are harmful chemicals, I do not think so, but I seal any remains in a plastic bag before putting it in the household waste bin.

Others will be along to advise and there are pictures some where of other peoples replacements.

Alan.

Station X · 1st Feb 2019, 6:11 pm

A coarse threaded woodscrew or better still a cork screw is useful for withdrawing the contents.

Never attempt to solder the new capacitor leads to the rivet heads inside the can, that leads to intermittent connections. Instead drill small diameter holes adjacent to the tags, thread the capacitor leads through them, wrap the leads round the tags and solder them to the tags.

Refugee · 1st Feb 2019, 11:35 pm

I found one with a bung that had soaked up the soda based solution from inside.
I was able to find some replacements that fitted in two holes side by side in the bung.
The remains of the old dual capacitor were left in the can with enough drilled out for them to slip in with a spot of epoxy to stop them falling out again.

1st Feb 2019, 5:13 pm	#1
MikeCross Tetrode Join Date: Sep 2016 Location: Tring, Hertfordshire, UK. Posts: 87	New Caps in old Cases I need to mount a new capacitor in an old capacitor case so that I can use its stud mounting facility. Has anyone any advice on how to remove the old cap materials from its case and replace with the new cap. Are there any dangerous chemicals within capacitors?

1st Feb 2019, 5:28 pm	#2
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: New Caps in old Cases If you put "restuffing" in the search box above you'll get a good idea of the techniques involved.

1st Feb 2019, 5:54 pm	#3
snowman_al Octode Join Date: Dec 2018 Location: Llandeilo, West Wales, UK. Posts: 1,092	Re: New Caps in old Cases The answer of removal depends on the original construction. Some are in a kind of wax. These tend to 'pull free' once the can is open if you drop them in near boiling water for a couple of minutes. Most are in a pitch like material. You can heat them up too, but I find it easier to drill the centre out and 'unwind' the foil a bit at a time. Older ones still have a fluid inside (likely borax) and just fall out. Make sure you insulate the inside of the can before fitting everything back together. I honestly do not know if any are harmful chemicals, I do not think so, but I seal any remains in a plastic bag before putting it in the household waste bin. Others will be along to advise and there are pictures some where of other peoples replacements. Alan. Attached Thumbnails

1st Feb 2019, 6:11 pm	#4
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: New Caps in old Cases A coarse threaded woodscrew or better still a cork screw is useful for withdrawing the contents. Never attempt to solder the new capacitor leads to the rivet heads inside the can, that leads to intermittent connections. Instead drill small diameter holes adjacent to the tags, thread the capacitor leads through them, wrap the leads round the tags and solder them to the tags. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

1st Feb 2019, 11:35 pm	#5
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,554	Re: New Caps in old Cases I found one with a bung that had soaked up the soda based solution from inside. I was able to find some replacements that fitted in two holes side by side in the bung. The remains of the old dual capacitor were left in the can with enough drilled out for them to slip in with a spot of epoxy to stop them falling out again.