[klondike98]

Arran, thanks for the tip of the cardboard wrapping as a shim. I've been placing a new cap into the tube and using a glue gun also, but without the shim its a bit of a balancing act to get the leads in the center while the glue cools.

[gregb]

The way I do mine is to cut strips of paper towel and wrap the cap until it is a snug fit in the tube. If the leads need to be made longer I add on the new lead so the joint will be within the body of the cap. Then I fill the ends with bees wax. I thought about using the glue gun but then I thought it might be tough for the future restorer to get apart without damaging the paper tube. The bees wax does look original as well.

Gregb

[klondike98]

Gregb, you're right, wax would make it easier for the next restorer. I'll try the wax approach.

[Arran]

Actually removing the glue gun glue is pretty easy, I've remelted it with a heat gun on occasion to make adjustments to the leads or to tidy up the ends. The melting temperature is lower then the hard wax the manufacturers originally used to plug the ends, it can also be cleaned up with lacquer thinner.
The cardboard I have been using is a sort of thin corrugated type used to package China ornaments for the stores. It has two or three layers and you can peel off a layer to make it thinner. I cut the strips so they are slightly wider then the body of the new capacitor, then I tack it one end of the strip onto the body of the capacitor and wrap it around the circumference.
I guess you could also use wax for filler, but finding anything other then paraffin candle wax around here is a problem. I don't like paraffin because the melting point is too low.
By the way, I test each capacitor on an EICO capacitor tester before and after I stuff it into the old tubes, just to make sure I don't have to pull it out again.
Regards
Arran

[morzh]

Testing caps is probably a good idea.....myself, never do it.
I am yet to meet my first bad aluminum can or film cap in my 32 years professional plus 13 years prior to that life.
Tantallums - that's another story, their infant mortality is just bad. And in some is simply horrific - I saw 10% of caps to heat up and melt off of the board I left in a lab overnight.

That is, I only use brands.

[gregb]

I must admit the bees wax is a little on the soft side but I liked the look of it. Maybe I will experiment with the glue gun on some no name caps. The last time I was in Michaels Crafts I noticed they had a number of different colours of glue sticks. Next time I will have a closer look to see if there is something I like.

Gregb

[gregb]

Morzh, I have had a couple of brand new caps fail in my years of service work. Had a guy bring a high end amp with some expensive coupling caps he wanted installed. He paid $600 for 6 caps and one failed on the first power up. Supplier gave us another no questions asked. The second one was not to long ago a 10uf 450v cap, shorted on first power up. I have always had the habit of testing every cap before installation so I know these two were good when installed.

Gregb

[Arran]

Maybe I should check the nearest Micheal's again about coloured glue sticks, the last time I checked was about a year ago and they only had the regular kind. Maybe word got up to head office that someone was looking for colored sticks? It could also be that the Nanaimo Micheal's is just a crappy store?
Regards
Arran

[morzh]

Greg

It depends. On brand. Also some schematics are plain illiterate.
Also people keep lytics on the shelf for years and then give it to you wihout reforming.

I do not even remember Soviet caps shorting and those were not as good.
Statistically they do fail...I guess...never saw it myself though.

There was that cap plague in the mid-2000s....yes.