The PHILCO Phorum

https://www.russoldradios.com/blog
 


Easier the second time - -

bad russ

very informative on the caps restuffed,, for the black beauties!

what i find odd is the end result looks just like orginal,, which if i were to have bought the set, i would automatically replace them. ,, thus wasting my time.

nice work there ,, i wish i was a purist doing this stuff but i am not.

I retained all my Bumblebees. In case I ever wantto restuff them.
But.....
My H500 and SK AWP8 were fitted with the yellow caps.

Good job, Russ.
I doubt many people will go for it though.

(01-25-2019, 04:37 PM)jcassity Wrote: [ -> ]very informative on the caps restuffed,, for the black beauties!

what i find odd is the end result looks just like orginal,,

Which was my objective.

I doubt that many others will attempt this.

Russ;
  I have seen two ways of restuffing a plastic molded paper cap, bumblebee, black beauty, Little Chief, including yours, the other way was to cut one end off and bore out the innards, and then replace the cut end. I found out something interesting about the Sangamo "Little Chief" caps though, for years I thought that they were molded out of polyethylene or some similar plastic, but whilst cutting one open I found out that they are molded in something resembling either Bakelite or melamine as the produce a fine dust when you cut them. I crushed the shell of the same cap whist trying to clamp it in a vise and the pieces were all rough and jagged, just like a phenolic plastic. I think I may try the line boring method should I restuff them, since I do have a small lathe.
Regards
Arran

I cut one. It is clearly not a polyethylene. It does behave like some backelite.

They are easy to crush once you begin to make a cavity.

The plastic smells like Bakelite which makes me wonder. The foils and insulators are not inserted in the tube like I am doing but it appears that the tube was molded around them. If it is Bakelite they must have had to heat up the whole assembly. Maybe this accounts for the poor performance. Either the insulator is damaged in construction or it is a material that can stand up to heat - but not years of service. When I drill it out it is just flakes.

So to clarify, you cut the end and drill, then glue the end back on with the new cap inside? I like the end result! I am dealing with these in a TV resto right now. I'm saving them, but didn't really know what to do with them. I might try this process and see how it turns out for another project.

Well, sort of. Using that method, of the 3 I described, I cut the wire off of the end without a ferrule(which is the foil/ground side). Then grind a small area flat so that the drill won't wander and drill through the end - through the foil and paper - until I hit the above mentioned ferrule. Heat the solder blob on the remaining end and the wire will fall out. Tap the body or blow out the solder to leave the hole in the ferrule clean.

Insert the new cap in the cleaned-out hole so that one lead passes through the ferrule (end). Seal the open end with epoxy or Bondo and paint black.

BTW, here is a picture of a CAST replacement (not made as above but cast in the red mold). This is the "death-cap" replacement and is rated for Y2 or X2.

[attachment=18399]

Yeah, my sanded resistor needs new sand, but, is otherwise OK.

Great work Russ.
Do you add a note anywhere noting the caps have been rebuilt?
I would probably cut that cap out you show, thinking it was old and had to go.

I put a business card into the battery area stating that it has been recapped.

On larger (expensive) projects, I will sometimes tape a card to the chassis - sometimes.

Thanks for the clarification Russ. I may try it on a couple of mine as an experiment. These must be bakelite. I saw a guy on Youtube heat one with a soldering iron while it was on a tester. It didn't melt.

Which brings me back to the question on post 7. I strongly believe that is why these fail at nearly 100%.