[Arran]

I just tried the recommended procedure by the "Philcorepairbench.com", and so far rebult two caps, 3615-J and 3615-L.

http://www.philcorepairbench.com/capbuild.htm

As promised, it was a snap, no fumes, not even slightest smell, very clean procedure.
The tar does not even start to melt, when it can be pushed out of the shell.

I use Milwaukee gun, and first I gently warm it on Low around for 2 minutes or so, and then I put the gun on Hi, and for 30 or so seconds from a very respectable distance (5-6 inches) warm it around, and then go back to Low, and in about 20 sec I push it out and it just flies out, leaving a very clean shell. The tar when picked up, is barely warm and even cool to the touch.

Instead of stiff wire to push the block out (wire may bend) I used the thinnest Allen wrench I could find, that actually fit through the central rivet, and as it is steel, it is as stiff as they come, and also dull at the end, so no puncturing occurs.


PS. I almost regretted this the caps inside look like new. All of them measured 0.1uF i/o 0.05uF, and I am not even sure it is aging - may be it was intentionally made higher.
With one cap the wire readily fell off the solder on the cap's side, the other was OK.
I am not sure what can go wrong with this caps actually, and rebuilding them only because everyone says they go bad after a while. They are actually working caps.

They use a paper dielectric just like any other bypass or coupling capacitor from the 1920s through the 1950s and it's the paper itself that goes bad. Quite often paper caps will read the proper value on a straight capacitance test but once you start putting a voltage across them they will fail.
Regards
Arran