[Ron Ramirez]

Russ, that is really neat! Forgive me if you've already answered this question on your blog (I confess that I haven't looked there...yet), but...would you care to explain your replating technique? I'm sure many of us would be interested in knowing more...especially those of us with old, rusty Philco tube shields which need a fresh tin plating...

[BrendaAnnD]

The only failures I've found inside the catacomb have been the interstage transformers. And you really have to dig into it to change those.

I have a couple of 26 "portables". Still trying to find either a complete horn or a horn driver for one of them. In the meantime, I have a 2" transistor radio speaker glued inside the original horn driver encasement, and an output transformer across the output. It sort of works, but I sure want to get it done right some day.

Also trying to find some appropriate material to replace the vibration dampers (lack thereof is keeping me from reassembling the radio and enjoying it). Any ideas?

I find their choice of IF frequency intriguing... 40 KHz. Lets me get strong stations pretty much anywhere on the dial I want.

[Phlogiston]

Russ, that is really neat! Forgive me if you've already answered this question on your blog (I confess that I haven't looked there...yet), but...would you care to explain your replating technique? I'm sure many of us would be interested in knowing more...especially those of us with old, rusty Philco tube shields which need a fresh tin plating...

I have a 55 gallon de-rusting tank that uses a 50A @ 12V supply, though I don't often have to use it. A lot of flaking plating or stains/rust can be removed with careful application of sulfuric acid which is a lot faster than navel jelly.

I have 5 gallon plating tanks for copper, nickel and bronze. The replating is usually nickel, not zinc or cadmium. It looks like fresh zinc and will stay that way. Acid copper can be applied over the nickel but not over unplated steel. Most of the plating supplies are from Caswell and are not cheap. I built the plating power supply which saved a lot of $$.

If you don't have a shop or a large SAFE area to work these processes are too toxic or otherwise dangerous to perform. De-rusting is always done outside. Combustible gasses may be released in these processes. Most of the plating solutions are toxic and cannot be released into the environment. I won't even consider chrome, though there are substitutes, nickel, if done properly is close enough.

Which brings up the point of tools needed for prep and polishing and more space and $$.

So this is something most people would not want to do. It is probably just too hazardous for people with young children assuming the work area can not be completely isolated. It is also too hazardous to do in a room of your home. It is too costly to setup for a single project. If you are not very careful with the process the solutions can be ruined. Like in painting, the prep is critical.

Pictures of the stripping process:

   

   
This is NOT the plating supply

   

Yes, the crud floating on top came off of the chassis.

P.S. the plating of the catacomb was a real quick job. I did not put much time or effort into the plating. I just did not want it to rust again.

Also, I get these 55 gal drums for about $15 and sandblast the inside. The process eats a hole in the bottom pretty quickly. Another reason to be outside. (The agent in the stripping barrel is washing soda. I would not drink it but it is not hazardous)

[Phlogiston]

The only failures I've found inside the catacomb have been the interstage transformers. And you really have to dig into it to change those.

I have a couple of 26 "portables". Still trying to find either a complete horn or a horn driver for one of them. In the meantime, I have a 2" transistor radio speaker glued inside the original horn driver encasement, and an output transformer across the output. It sort of works, but I sure want to get it done right some day.

Also trying to find some appropriate material to replace the vibration dampers (lack thereof is keeping me from reassembling the radio and enjoying it). Any ideas?

I find their choice of IF frequency intriguing... 40 KHz. Lets me get strong stations pretty much anywhere on the dial I want.

I am not familiar or don't remember that chassis but if you are talking about the isolation bands like on a Radiola III or the early Federal radios (59, 58, 61 and such) then I use heavy rubber strips cut from flat material that I got somewhere(?) probably old Telco projects/waste. I think I used the last of what I had yesterday to mount the C supply (transformer supply removed from a wall-wart) inside of my new power supply project. I am going to have to see if I can find some more. It is a little less than 1/8 " thick, black rubber.

Radiola IIIA:

I also replated the structural components in this radio.

   

Closeup of anti-vibration/microphonics suspension.

   

Also (again) I would not try "digging" out anything in a catacomb or any other potted device , like an AK power supply. I use a oven, also outdoors and carefully monitor the temperature to de-pot these devices. The setup prevents unexpected movement (weight CHANGES as the tar/wax melts) and catches the tar for repotting. All of these devices are completely rewired.


An AK supply After/Before rebuilding. You know that the transformer can put 800+ volts on some of that crispy old wire. Every time somebody says "just dig out the caps" it make me cringe

[Arran]

I have a 55 gallon de-rusting tank that uses a 50A @ 12V supply, though I don't often have to use it. A lot of flaking plating or stains/rust can be removed with careful application of sulfuric acid which is a lot faster than navel jelly.

Ihome. It is too costly to setup for a single project. If you are not very careful with the process the solutions can be ruined. Like in painting, the prep is critical.

Pictures of the stripping process:




This is NOT the plating supply



Yes, the crud floating on top came off of the chassis.

P.S. the plating of the catacomb was a real quick job. I did not put much time or effort into the plating. I just did not want it to rust again.

Also, I get these 55 gal drums for about $15 and sandblast the inside. The process eats a hole in the bottom pretty quickly. Another reason to be outside. (The agent in the stripping barrel is washing soda. I would not drink it but it is not hazardous)

Russ;
  I really need to get my derusting tank going again, what I used last time was an old plastic garbage can, filled with a water and washing soda mix, but I used half of a rusted out lawnmower deck for the sacrificial anode. What I really need is a better high current DC power supply for the tank, I was using a car battery charger which puts out unfiltered DC, electrolysis really works better with a clean DC power supply since polarity is so important.
  What I would like to have for a new tank is something like a carwash soap barrel, the garbage can works but the sides taper inward towards the bottom which makes stripping some objects awkward. Another possibility is to use a kiddie pool, and put the sacrifical anode in the bottom with bricks or blocks between it and the object that I need to strip. A guy I follow on You Tube uses a dead chest freezer for his tank, and isolates the cabinet from the anodes, which are sheets of scrap diamond mesh/expanded metal, he also uses an old computer power supply for the DC.
  Just as a word of warning to anyone trying this, do not use stainless steel for sacrificial anodes, it can create hexovalent chromium apparently which is toxic waste, regular scrap steel and iron is everywhere so there is no advantage to having a longer lived anode. In my opinion the risks of hydrogen buildup from the process is way over blown, there may be some but it's so little that you won't get enough of it to burn, believe me I've tried. Also, if your sacrificial anode gets really cruddy you can clean it off by reversing the polarity using another chunk of scrap, it should work with cleaning the inside of an oil drum as well.
Regards
Arran

[Phlogiston]

In my example the 55 gal. drum is the anode. There are a lot of those drums around here, cheap, used for burning barrels. When I rot one out I get another dropping off the old one at the metal recycler on the way. I usually fill the old one with other metal scrap. They will actually pay for the scrap but I usually just drop it off and move on.

When using a high current supply there is a lot of gas coming off. This also depends on the size of the item you are derusting. 12V seems to be about right (other voltages for plating). So watch your supply for a voltage drop. If it is cutting back (regulated) it probably isn't big enough.

PS: That is REAL WE wire on the supply. It is probably worth $!,000.000. It makes my supply sound better with clear highs and a solid bottom end (not like mine) with just a whiff of lavender.

Remember when Circuit City went out of business? That supply ran the local car radio display. It was hooked to a battery and could deliver 300A that way. I run it without the battery (heavy enough). The supplies are expensive but when they were closing I got it for - - - $25.

[Phlogiston]

Notes on issues within the catacomb added to blog.

She is up and running on my new power supply. The volts/amps meter on all of the B and A voltages has already helped in resolving a current consumption issue. The PS took more time than the resto but can be used on almost any battery radio.

I'll ad a video soon.