|
Cabinet and Chassis Restoration and Refinishing For help with cabinet or chassis restoration (non-electrical), please leave a message here. |
|
Thread Tools |
6th Mar 2014, 12:23 pm | #1 |
Retired Dormant Member
Join Date: Feb 2014
Location: Edinburgh
Posts: 12
|
Chassis Cleaning
Hi,
I need some advice about cleaning a chassis. The dust has been removed already. However, the chassis has light rusting. It has been said to remove light rust with White Spirit. The chassis also has a grey coating. My question is; will White Spirit remove the grey coating as well? There is some rust as well on top of electrolytic cans? Should I use as well White Spirit here? Last question, what to do to avoid rust coming again? Regards Last edited by AC/HL; 6th Mar 2014 at 12:33 pm. Reason: Readability |
6th Mar 2014, 12:57 pm | #2 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,924
|
Re: Chassis Cleaning
Are you going to try and do this with the components in place or will you be dissassemble everything? Big question is whether the rust is only in the places where you can see it, or is it also hiding underneath the paint. White spirit is really just a degreaser. I'd say the rust has to go completely by abrasion, or the worst removed by something like brushing and then a quality rust-defeating (chemically active) paint applied; something like Hammerite Rust Beater, but there are many others.
B
__________________
Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch. Last edited by Bazz4CQJ; 6th Mar 2014 at 1:05 pm. |
6th Mar 2014, 1:01 pm | #3 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,528
|
Re: Chassis Cleaning
A forum search on "rust removal" (search box top centre of window) will turn up plenty of suggestions, counter suggestions and discussions.
One thing...... Aluminium capacitor cans and IFT shields don't rust though they may get corroded, so rust on these should be quite easy to dislodge. Biggest problems are usually access and preserving markings and remaining good paint etc.
__________________
....__________ ....|____||__|__\_____ .=.| _---\__|__|_---_|. .........O..Chris....O |
6th Mar 2014, 2:15 pm | #4 |
Nonode
Join Date: Jun 2007
Location: Coulsdon, London, UK.
Posts: 2,152
|
Re: Chassis Cleaning
If you use abrasives to remove the rust (iron oxides) you will create dust which can damage loudspeakers, switches, potentiometers, bearings, etc.
It could be done outdoors with a vacuum cleaner nozzle in one hand to remove the dust. Alternatively wet the rust with a rust converter and sand it with 'wet & dry' paper or 'Scotchbrite' pads. Wear gloves. Corroded aluminium is softer and a non scratch kitchen scourer wetted with white spirit would remove most of the dirt and corrosion. |
6th Mar 2014, 3:23 pm | #5 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
|
Re: Chassis Cleaning
Is this is a Murphy chassis?
Either way, after removing all the dust with a paintbrush and vacuum cleaner and/or an air line, I'd use nothing more than a briusk rub down with an old rag lightly moistened with WD40, followed by a polish with a soft duster with a squirt of Pledge on it. It won't be like new, but it will be clean and "honest" looking, as opposed to over-restored. Then keep it in a dry place so it doesn't develop more rust specks. Nick. |
6th Mar 2014, 3:37 pm | #6 |
Nonode
Join Date: Jun 2004
Location: Norwich, Norfolk, UK.
Posts: 2,543
|
Re: Chassis Cleaning
It doesn't look that bad to me. I use white spirit to just clean general muck and dirt from a chassis, I doubt it would do anything to rust.
I can't tell if the chassis is painted or plated? Acid based rust removal products will remove zinc plating and could leave you with a bigger rust problem in the future. David
__________________
http://www.youtube.com/ My Nixie Clocks Last edited by Radio_Dave; 6th Mar 2014 at 4:01 pm. Reason: typo |
6th Mar 2014, 3:39 pm | #7 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
|
Re: Chassis Cleaning
Looks like grey paint to me, David.
|
6th Mar 2014, 4:43 pm | #8 |
Octode
Join Date: Nov 2005
Location: Surrey, UK.
Posts: 1,869
|
Re: Chassis Cleaning
Your chassis looks like a Murphy A104. This is a steel chassis painted with stoved grey paint which will not be affected by white spirit. I find this is a good cleaning agent which will go some way towards preventing further rust in slightly damaged areas. It also does not affect materials used elsewhere in radios of this vintage.
Unless you are after "as new" appearance - in which case you would have to completely strip the chassis (something I would never do), a clean with white spirit using cotton buds in tight places is a good plan. Aluminium electrolytic and IF transformer cans do not rust, just corrode. Brasso or duraglit cleans these items effectively. If you re-align your A104 (if that's what it is) beware the bakelite IF core adjusting screws. They become stuck in the rusted locknuts and extreme care is needed to free them. Setting the optical SW scale so that the optical magnification matches the electrical bandspread requires several beers... Leon. Following a better look, the tuning drive is not right for an A104 - it could be an A122. If so, the optical comments do not apply. Last edited by Leon Crampin; 6th Mar 2014 at 4:46 pm. Reason: Second thoughts. |
6th Mar 2014, 5:14 pm | #9 |
Retired Dormant Member
Join Date: Feb 2014
Location: Edinburgh
Posts: 12
|
Re: Chassis Cleaning
Thanks for your opinions.
It is a Murphy A122M, (I should’ve said before) The radio works fine (although I don’t use it, at the moment). So I don’t really want to dismantle everything. I already remove the dust with a brush, and that’s what came up. It looks paint to me, although I’m not sure. I’m not after “as new” appearance, because it doesn’t look too bad to me, so I’d be happy with a good clean (without bothering much other components), and prevent rust for the future. |
6th Mar 2014, 8:12 pm | #10 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
|
Re: Chassis Cleaning
So Leon was right (as usual!).
The rust will have been caused by cold/damp (loft?) storage leading to condensation on the metal components. It's very superficial and won't progress if you keep the set in the house. Nick. |
6th Mar 2014, 10:09 pm | #11 |
Retired Dormant Member
Join Date: Feb 2014
Location: Edinburgh
Posts: 12
|
Re: Chassis Cleaning
Leon was spot on, and you were right as well.
Thanks |
7th Mar 2014, 3:06 pm | #12 |
Retired Dormant Member
Join Date: Sep 2007
Location: Maidstone, Kent, UK.
Posts: 109
|
Re: Chassis Cleaning
I take the valves out and put the chassis in the dishwasher, about 40 degrees for 1/2 hour with a tablet. They really come up nice, but if they're really rusty I strip the thing, wire wheel it and paint it with silver spray from Poundland. I've done about 15 or so this way and never had a transformer failure, although cardboard electrolytic covers go soggy and fall off.
|
11th Mar 2014, 12:20 am | #13 |
Retired Dormant Member
Join Date: Feb 2014
Location: Edinburgh
Posts: 12
|
Re: Chassis Cleaning
I’ve cleaned the chassis with White Spirit. It looks the same than before, (the light rust still there) but if I pass my finger it’s clean. All the grime is gone.
This is the state of the of the scale assembly (in the Murphy A122M). The paint easily came off. What could I do about it? How to stop the paint coming off or get rusty in the future? |
15th Mar 2014, 12:13 am | #14 |
Hexode
Join Date: Apr 2007
Location: W Yorks, UK.
Posts: 406
|
Re: Chassis Cleaning
Rub it with wax and don't let it get damp?
|