repair chrome plating

[audio-kraut]

Hi,

I acquired an sme 3009 at a decent price - below 100$ - which had parts missing.

Parts are there now, but the armtube was a bit scracthed up.

Tried to polish using 000 steelwool and # 800 and 1000 sandpaper and brasso.

Most of the scratches are gone now, but where the severer ones were I worked down to the original metal.


Is it advisable to repair using a small chromeplating kit like this one:

http://www.caswellcanada.ca/products...7&gosearch.y=8

and do I have to take the old plating right off or can I just plate over it?

Thanks for any help in advance.

[phn]

Since nobody has answered and you probably want to have the tonearm fixed and up and running...

My advice is to ask a company that does these things.

[audio-kraut]

Hi phn,

the arm is aluminum, and therefore anodized - as I found out.
I removed the old anodizing, polished the arm (after removing the wiring and the cartridge plug in) and will send it now to an anodizing shop here in canada (alberta).

Sending it to SME would have involved major layout of non budget funds. Just check what SME charges for an rca converter kit - over 100 pound sterling. Same thing from germany - 33 euros.

Thanks anyway for the reply.

[phn]

I'm a bit puzzled here. Isn't that a high-gloss wand? Anodized aluminum is rather dull. I can be wrong, but I think it's lacquered alu.

[audio-kraut]

You are right, it is high gloss, but it was definetely some layer on top of
the original aluminum - took quite some time to remove it.
I am down to the original aluminum now, and have it polished just nicely.
I am considering just applying urethane lacquer (spray).
Had done this to a labelled frontplate and it lasted forever - even scratch resistant.

[bulgin]

Hi audiokraut

That SME arm is polished, lacquered aluminium - no anodising, like phn said. I have a 3012 with a very minor mark left by the armrest clip.

Anyway, imho you should have started cleaning with 3M waterpaper (wet or dry) at about 600grit, them move to 800, 1000 and 1200grit. Then, if there is a hobby or craft shop near you, get some Japanese-made Tamiya finishing abrasives. These come in small cellophane packs with grit grades from 1200 to 2000.

Be sure to get only 3M waterpapers for the coarser work. I found some other brands for some reason or other, embed grit into the job while sanding.

The last step would be to use a fine polishing paste. Mine comes in a little blue plastic box and is sold also by hobby shops or by agents for Proxxon tools. This stuff is superb and will give your arm a mirror finish.

bulgin

[poobah]

Toothpaste will make a nice DIY polishing compound... cheap, and I'll bet you have some (well I hope so).

[EC8010]

My SME3009/S2 was very definitely chrome-plated aluminium. The previous owner managed to damage it when he tried to fit an ADC magnesium headshell. (He apparently gripped the arm tube with a pair of serrated edge pliers then twisted the tube so that it graunched. Hooligan.)

[poobah]

I had a guy do that to 80 backshells for military connectors ($40 apiece) because he thought wrapping some rubber around them first (as was demonstrated to him) was too much work. FIRED!

[auplater]

You might consider a buffing wheel and either tripoli or white rouge, using a soft fabric 6" wheel and a fairly light touch, you should be able to buff out ALL scratches to a mirror bright finish... then a quick wipe with alcohol or MEK to remove waxes and spray lacquer will be MUCh cheaper and look as good or better than chrome plate... a not so trivial job on aluminum anyway.

auplater