Chassis cleaning and protection ideas ?

[g4wim_tim]

Hi

I'm gradually bringing an Eddystone EA12 back to life and have stumbled into a bit of a problem.

The PSU and IF chassis was looking quite dirty and spotty in places - it looks as though the chassis was originally cadium plated when new, but the years have taken their toll.

So I decided to clean it up a little using nothing more than switch cleaner and a tooth brush - which had zero effect.

So decided to try a very mild abrasive which immediately removed what was left of the cadium plating to reveal a nice shiny chassis which appears to be made out of steel as it's magnetic.

Not what I was expecting or hoping for.

Question, any ideas on how to 're-treat' the exposed chassis to prevent corrosion and preferably at least make it look like it's plated.

Regards Tim

[G6Tanuki]

There's no real easy answer to the cosmetic part apart from getting the chassis replated!

To preserve the chassis from ongoing corrosion in the absence of the plating; keep it in an environment where the relatibe-humidity is low [I run a dehumidifier in my office/workshop - it keeps R.H. below 50%] and when the radio is not in regular use consider using some of the brown "vapour phase corrosion inhibitor" paper beloved of engineering-workshops for decades when they need to store machined componets, cutting-tools etc. A quick Google for "VCI Paper" will show you the way.

[Panrock]

If you want to do the job properly, G6Tanuki is correct.

However a 'dodge' (or bodge?) would be to lightly spray it (deftly, with a few moving puffs) with a 'silver mist' dull silvery type of car aerosol. Not shiny silver mind you. This can produce surprisingly convincing results.

Steve

[g4wim_tim]

I was thinking about applying a thin coat of varnish - but not sure if this would have any unintended consequences, apart from being difficult to remove if it didn't work out !

My thinking being that varnish would help keep corrosion at bay and it would look similar to cadium plating.

I could even give the other chassis a coat to make it match and maybe slow the corrosion on that side as well.

Luckily the shack here is indoors and fairly benign but doubtless overtime corrosion could still set it.

Edit Steve

I had though about stripping it down to a bare chassis and replate etc but decided against it as I doubt I have the patience or skill to make it look original again.

[Bazz4CQJ]

Switch cleaner (probably IPA) is not best suited to taking off heavy dirt; you might try either white spirt or WD40 on a Q tip.

Is it possible that the mild abrasive was a bit more aggressive than you had believed? Solvol's "Autochrome" polish maybe one to try.

Restoring it to its original condition sounds like a major challenge and you may have settle for just stopping it getting worse. Something like Tanuki's inhibitor paper, or the cautious application of WD40 using a small brush on the metal-only parts, may be the best you can do.

B

[ChristianFletcher]

A wipe over with linseed oil will provide protection if you like your radios rat rod style. In my experience if the radio is stored in the house rather than a damp shed the corrosion won’t get any worse. For cleaning WD40 works well often with help from steel wool. I also like to finish with IPA or Acetone to remove any remaining oil or grease

[falcon123]

on my hallicrafters sets i have actually removed the serious rust and tinned the affected areas with solder wiping of the excess with a cotton rag while still molten. you will find it will dull and look like cadmium after a while. you are quite correct about the "leopard" spots on the chassis.the most i will do is thoroughly clean the surface using fine steel wool. then a careful detergent wash rinse and dry. i then apply butchers paste wax with an acid brush. i dont buff it off but let it dry. like the linseed oil, it maintains the status quo. some folks strip the chassis and paint them others send the stripped chassis out for re-plating. a canadian company CASWELL had some home plating schemes that might bear looking into. its like most things in life,you gotta decide what you want,what you can afford, and devise a plan to get there. the paste wax plan works the best for me.

[murphyv310]

Hi.
From this to that in the photos.
Not for the feint hearted and many criticise me but I've never had and issue and done loads this way. The chassis was from the dirtiest TV62 ever. Washed with TFR (traffic film remover) 100 bar of pressure and a 65 degree nozzle. Proper rinsing and drying after many hours at 60c with a fan heater.
TV works perfectly after recapping etc.

[G3PIJpeter]

If the original finish was cadmium plating, then be careful about what happens to any dust from cleaning. Cadmium is poisionous - see https://en.wikipedia.org/wiki/Cadmium_poisoning . The current advice is to contain, not remove.
-Peter

[murphyv310]

Hi.
I think that there is virtually no chance of having any problems working with cadmium plated chassis. The sets I've come across the plating has eroded away gradually over the years, where too is anyone's guess. Actually washing the way I do is far safer than using a dusting brush in a confined space!

[Sparky67]

I had an issue cleaning cadmium plating on oxidising steel in a RA1778 a couple of years ago and found out cadmium dust is nearly up there with beryllium dust in toxicity. A minute amount in a standard shack-size environment quickly hits the exposure limit. Take care with the stuff…!

I support the containment method on chassis which have damaged plating, so spraying over with something which acts as a sealant downwind in the open air is preferable. Abrasive refinishing is definitely best avoided.

Martin
G4NCE

[G3PIJpeter]

Cadmium plating is known to produce a 'bloom', especially when stored in damp environments. The example at https://www.psmagazine.army.mil/News...-ko-corrosion/ states: "Bloom occurs when cadmium transforms into cadmium oxide, a powder-like residue that forms on cadmium-plated components". Not nice stuff - hold your breath!
Peter

[g4wim_tim]

I'd forgotten what nasty stuff cadium is, fortunately the abrasor I used was damp so any dust would have had much chance to get airborne - or at least I hope that was the case.

I must say the plating much have been very thin as it disappeared almost instantly once touched with a 'magic white cleaner' block.

I've given the affected chassis a wipe over with Osmo oil - only because I had some to hand and it looked a similar colour !

As it turns out the layer is so thin you can hardly tell it's there !

As an aside while overhauling the tuning gear box due to the anti backlash gears not working I discovered that someone had managed to get a super glue type stuff between the gear wheels ! No wonder there was back lash but all good now.

[stevehertz]

Personally I don't use abrasives on chassis, I clean them up using a rag and cotton buds for the less accessible areas, then wipe any rusty areas with a small amount of oil, changing the rag surface until the area changes from brown to black. I leave a small amount of the oil in place to prevent further rusting. If that method is not 'fine' enough for your desired appearance, then a complete strip down and repaint or re-plaiting will the job. The former method may be less than an hour, the latter several weeks.

[nutteronthebus]

I use Axminster tool wax on various bits and pieces . It comes in 20mg tins but goes far
Dave