The PHILCO Phorum
Can Capacitor Opening - Printable Version

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+--- Thread: Can Capacitor Opening (/showthread.php?tid=14686)


Can Capacitor Opening - Bill Bacco - 05-29-2016

I am curious about the best way people have found to open can capacitors for restuffing.  The one I am currently trying to do is a Philco Part #7558-S.

Any tips, pointers or suggestions are appreciated.

Thanks, Bill

RE: Can Capacitor Opening - klondike98 - 05-29-2016

Bill, what radio is it on?  The can cap in my 60MB was straight forward and with a little unbending of the metal tabs the tar encrusted caps slid out with the fishpaper.  Others will have to comment on other models.

If you are speaking about those black bakelite block caps, then here's a thread for those.

RE: Can Capacitor Opening - morzh - 05-29-2016

There are all kinds of cans. Those rectangular ones like in 20/70/90 are the easuest. Just fishpaper. Undo brackets, it slides out. I always salvage the GND wire. No potting after restuff.

RE: Can Capacitor Opening - Bill Bacco - 05-29-2016

Can is from an Model 81 Jr.  Attached are a few pictures.  After I posted this I did find a thread where Ron showed how he rebuilds them.  My basic question now is how best to open one.  I saw some people using hacksaws, others using a dremel tool.

RE: Can Capacitor Opening - Warren - 05-29-2016

You can also use a tubing cutter to open them .

RE: Can Capacitor Opening - klondike98 - 05-30-2016

Here's a service tip from Chucks site:  

http://www.philcorepairbench.com/tips/svctip46.htm

There are some pics in that 60MB post of the round can type being stuffed.  I have used a hacksaw blade to open, but I get a neater cut with a box cutter blade.  I place the blade on the can with a little pressure and roll the can back and forth working my way around the can.  As with a pipe cutter, you go slow making the cut in the can a little deeper each rotation.

RE: Can Capacitor Opening - Bill Bacco - 05-30-2016

Thanks everyone. I think I have all that I need to get started. The only thing remaining is a little bit of time.

Best Regards, Bill

RE: Can Capacitor Opening - morzh - 05-30-2016

I use pipecutter, but it smushes the can a bit. Not a very precise yool when dealing with a very soft thin metal.

RE: Can Capacitor Opening - klondike98 - 05-30-2016

Yep, mike, thats why I use the box cutter blade. Sharper, narrower than pipe cutter.

RE: Can Capacitor Opening - morzh - 05-30-2016

I recently started using bandsaw. Have it at work.

RE: Can Capacitor Opening - Kenneth F. Besso Jr. - 06-01-2016

        ultilty knife works really well,,stab it in and work it around,,about 1 " from the base

RE: Can Capacitor Opening - Kestas - 06-14-2016

I just want to add that after cutting, I iron out the dents on the can by slipping in a large socket from my toolbox and rolling.

RE: Can Capacitor Opening - morzh - 06-14-2016

I simply try to cut it where it won't be noticeable too much.
Say the cap is held by a clamp by its bottom side. So I cut it such that the cut will be concealed by the clamp.
If a cap is screwed to the chassis and has the cap separated by a groove, then I cut right at the groove and then simply glue the cap in place as it is not mechanically stressed.
If a cap is screwed but has the indent at the bottom, which is about 1/8" wide, then I cut at the very upper border of the indent, which serves two purposes: 1) the main cut part has no narrowing so the guts are extracted easier, and 2) the indent then, after some manipulation, can be inserted inside the main part which still preserves the caps' looks though the indent itself becomes a smaller groove.

Any way of cutting without smooshing the can is good.
When using band saw which produces very accurate cut, the cap has to be advanced a little at the time, first one turn, and then another, or else the saw will pick up the can damage it somewhat, plus there is a possibility of tossing it across the room. So need to be careful.

RE: Can Capacitor Opening - mikethedruid - 06-14-2016

I use a cutting disc on a Dremmel tool, and cut carefully around at a point where the clamp will cover the cut. I use this aluminum tape that I bought at an auto supply store to tape it together. I cut a strip narrow enough so that it will be completely covered by the clamp. If no clamp, as on yours, then the aluminum tape is close enough to not be easily noticeable. In that case I would cut about 1/4 inch above the base, and cut the strip of tape about 1/2 inch wide.

RE: Can Capacitor Opening - Kestas - 06-14-2016

There are many different style cans out there. The one Bill shows is the one I like to restuff. The cut can be made just under the top where it's not noticeable. And when restuffed and glued back together, the can still has strength if you should grab it while handling the chassis.