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Old 8th Apr 2012, 2:47 pm   #21
jcaines
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Default Re: Chrome stripping

If it's of any help, a reference book I have gives the composition of 'Mazak' No3, apparently the best known alloy, as

Aluminium________________4.1%
Magnesium_______________0.04%
Zinc 99.99 + % purity______balance

there is also an alloy 'Durak' which is almost the same except that it contains 1% Copper

John
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Old 8th Apr 2012, 2:50 pm   #22
bluepilot
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Default Re: Chrome stripping

Glad to hear the first step went OK. For the next step, this might be useful:
http://www.caswelleurope.co.uk/nickstri.htm

NaOH definitely attacks aluminium. Many years ago people used it to clean the fat from frying pans etc. You were warned not to use it on aluminium pots.
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Last edited by bluepilot; 8th Apr 2012 at 2:54 pm. Reason: Added bit about NaOH
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Old 14th Apr 2012, 12:08 pm   #23
musonick
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Default Re: Chrome stripping

The story so far:

I had a reasonable amount success this morning. As stated before the hydrochoric shifts the chrome with ease. The nitric acid has, indeed, dissolved both the nickel and copper layers. The base alloy shows no visible sign of reaction and can be quickly and effectively neutralised due to the rapid effect of the acids. One problem I did not consider was the exisitng, natural erosion of the already exposed base alloy. This has left a very slightly uneven surface but I am confident this can be sorted with the polishing wheeel and suitable compound.

Nick.
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Old 14th Apr 2012, 6:08 pm   #24
Sean Williams
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Default Re: Chrome stripping

I wouldnt polish the base material - get a good layer of copper onto it, and use it as a filler - it's how plating is done professionally.
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Old 14th Apr 2012, 8:25 pm   #25
musonick
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Default Re: Chrome stripping

Thanks Sean,
I'm afraid the de-plating was nerve racking enough let alone plating!
Only two of five pro electroplaters responded to my enquiry, the least expensive estimated at 1,200.

This plater had experience with Rockolas and also suggested polish finishing as an alternative.

The base metal (Mazak? Still not certain) polishes very well with the correct compound and will be lacquer coated.

Should I ever decide to have the jukebox plated, the bulk of the prep work will already be done.
I will post some pics when the box is finished; hopefully in the 'Success Stories' section!

Nick.
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Old 15th Apr 2012, 10:12 pm   #26
Bazz4CQJ
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Default Re: Chrome stripping

A couple of points;
i) as pointed out previously in the thread, sodium hydroxide solution dissolves aluminium, however, we used to use a brief immersion (~20-30 seconds) of some aluminium components in hydroxide solution as a means of cleaning up their surfaces. When taken out of the hydroxide, they were quickly washed in water then dipped in nitric acid for 5 minutes to passivate them at which point they looked like new. Not sure if this might reduce the amount of polishing needed.

ii) if you can get hold of the right materials, electroless nickel plating is very easy to do. We had a small tank for doing at this a place where I worked - all kinds of stuff got put in there - one bloke put his son's first shoes in and did a good job! Also, there are a variety of kits for swab or wand plating on the market. The chemicals are not too expensive but they mainly make money selling small DC psu's for silly prices. I've put down gold and platinum layers with that technique.
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Old 16th Apr 2012, 3:29 am   #27
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Default Re: Chrome stripping

I am reasonably confident of having a go at the plating but I am pressed for time as the jukebox needed for a shop window prop in the next couple of weeks.
I have been told the the plating would be a 4 stage process due to the base metal. Zincate, copper (filled & polished), heavy nickel, then chrome.
I will have to polish out where 'old meets new' at this point anyway, as you say bazz, the base metal does look like new.
So far, so good. and plating is definately a consideration for the future.

Nick.
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Old 12th May 2012, 9:19 am   #28
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Default Re: Chrome stripping

Hello All,
Firstly, a MASSIVE THANK YOU for all that contributed to this thread. The Rockola is just about complete with just the original stand and the odd snag to sort out.
The mirror polishing was very difficult (for me) to photograph but here are a few photos of the jukebox.
I will post a comprehensive piece in 'success stories' if anyone is intereseted as this box was in a sorry state and it has been quite a labour of love restoring her.
Also, If anyone is interested in the full (and final) chrome stripping and polishing process, please let me know and I will detail it as far as my experience goes.
Thanks once again all.

Nick.
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Old 12th May 2012, 10:06 am   #29
Sean Williams
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Default Re: Chrome stripping

While I am no fan of the styling, the results are certainly impressive - a credit to your tenacity and dedication!
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Old 15th May 2012, 8:53 pm   #30
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Default Re: Chrome stripping

Thanks,
I take no responsibility for the styling, you can blame David Cullen Rockola for that. His company sold quiet a few machines over a century.

Nick.
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Old 15th May 2012, 10:48 pm   #31
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Default Re: Chrome stripping

What year is that model ?
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Old 16th May 2012, 12:24 pm   #32
musonick
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Default Re: Chrome stripping

The Original 1484 model was 1960. This box is a 403 from 1962. I used a 1960 colour scheme on the mech cover and cabinet because I prefered it. Easy to return to original which was too far gone to preserve anyway.
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Old 31st May 2012, 8:56 pm   #33
thebirdman
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Default Re: Chrome stripping

Thanks for the info Nick. Just joined this forum as I also have a 1484 that needs its chrome parts dealing with. In a previous post you offered to give full details of the process and I would be really grateful if that could be put up or emailed (not sure of the protocol on here for that as only just joined). Where did you get hold of the chemicals etc? A couple of local jukebox specialists nearby (Sheffield) have said that this particular model would be about 500 to rechrome, but that seems cheap from your experience, so I'm not sure if they're quoting for the whole process, stripping prep and plate, or just part of it.

Any info you can give from your experience would be very well received. I've not had the machine long and although it sounds OK, needs the cosmetic work and a recap later as well.

Cheers
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Old 1st Jun 2012, 12:51 pm   #34
peter_scott
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Default Re: Chrome stripping

A friend of mine has had good experience of this company:

Prestige Electro Plating
Unit 9 Station Road Industrial Estate Wombwell Barnsley S73 0AH
Contact: Mr. Brian Perkins 01266 751 389

Peter
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Old 1st Jun 2012, 9:55 pm   #35
thebirdman
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Default Re: Chrome stripping

Thanks for the info Peter. I work in Barnsley every week so I'll give them a try
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