[Arran]

Ron's thread with the Philco Tropic reminded me of something I have been working with lately, the post showing the filter caps. I've been contemplating ways to restuff twist lock electrolytic cans myself, mainly for a vintage TV project. One way would be to use a pipe cutter and cut the can somewhere above the bottom, maybe 3/4 of an inch up, heat up the can, and then pull the contents out with a corkscrew or a deck screw. But then you need to find something to couple the two sections together which is not always easy.
I had to do this with a pair of filter cans in my Rogers Ten-60, it had a pair of dry electrolytics where someone crudely cut each can in half with a hacksaw and then attempted to glue them back together with contact cement. I took them apart, cleaned off the goo, and then wrapped each section with a band of masking tape, then filed down almost to the tape line, then honed each edge perfectly flat on a piece of 600 grit sandpaper on a chunk of granite. I got lucky with the first can, the outside diameter of a 3/4 inch PVC pipe coupling almost fit perfectly, a little bit of hot glue and it was back together, the second can is larger so I will likely need to make a coupling by turning down something slightly larger.
I think the method Sylvian used would be the best, cut or pop the cap off the top and use something like that orange juice cap to couple it back together. I only did it this way because I had no choice if I wanted to salvage the old cans, some prior repairman made the decision which method I had to take.
When it comes to the twist lock can caps they don't have a cap crimped onto the top, the bottom is crimped on. Bob Andersen's method certainly works but it involves uncrimping and recrimping the bottom of the can to get at the insulating disk. The only problem I see is that electrolytics have a life span, good quality ones can last for decades but even that isn't guaranteed, and you can only fold aluminum over so many times until it snaps off, should you have to open it up again.
However there is a similar method that someone else used on the other forum that is very similar, they filed off the crimped section altogether and glued the lip of the can that the bottom disk fits into onto the can. The one change that I would make is to use hot glue to cement the disk in place rather then epoxy, contact cement, etc, then all you need to do is heat up the can to get open again.
Regards
Arran

[morzh]

Arran

Sorry for a dumb question: what is "twist lock" electrolytics?

[kporter]

Those are electrolytic caps in a can with usually about three little metal tabs at the bottom of the can. The tabs fit into corresponding slots in the chassis, and then after sticking them into the slots you take your pliers and bend (twist) them a quarter of a turn to lock them into place in the chassis. No screws or mounting clamps required.

[Arran]

Sometimes they are also called "twist cans" they were very commonly in use from the late 1930s probably up until the 1980s. While they often attach through slots in the chassis many are installed on a mounting plate which can be steel or phenolic depending on the application. Here is an example:

http://store.triodestore.com/twisel.html

They are still available new but usually with inflated prices, as this guy has, and limited selection, probably because of the guitar amp guys. Old TV sets often used several of the things, my old G.E COT4 uses three or four of them, along with at least a half dozen axial lead ones with spade terminals instead of wire leads.
Regards
Arran

[Conelrad]

This guy does a better job IMO, and is cheaper:

http://hayseedhamfest.com/capacitors.html

Dennis

[morzh]

Wow, this is good!
I had to re-stuff mine on my Zenith-6G001 portable.
had I known....it's a mess to restuff them.

However it came out fairly neat, and here's why: there is a groove at the bottom, so I cut it along the groove, so after that the lower half sort of coned inside the upper, so I just put some epoxy and it looked almost like it was always that way.

[gvel]

I second hayseed hamfest!

I've purchased 2 twist lock cans and a couple of 4 section cardboard types from them.

The work is quality and the service is great.

[Michael Dennis]

So that's what they're called.....

Mike

[Arran]

I just posted that link to illustrate what I was talking about, I would never recommend paying anything near that for one, new product, NOS, or restuffed. But in the case of a vintage TV, and many radios, it's nice to keep the original can on top of the chassis if possible. I've never found it that difficult to remove the contents of any dry electrolytic once you get them open, a corkscrew or a wood screw driven into the roll, a little heat, and the contents usually just slide out, but getting them back together is what I'm thinking of.
Regards
Arran