ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi,
I was lucky enough to pick up a nice pair of M70s off craigslist complete with trumpet stands (one dead woofer, but replacement is on the way).
The stands are aluminum I believe. As you can see in the photos they have some discoloration. They are still smooth if you run your hand over the discoloration.
What would be the best way to go about tidying these up?
Many thanks,
H
Using a rotation sander (don't know the english word) or a repaint job?
Brengen & Ophalen
Isn't the alu anodized? If so you can't just sand it, can you?
Jacques
As far as I know not or else I was not able to do it.
Hi Leslie!
So did you spray a protective coat of varnish then, to prevent re-oxydation?
No I did not use varnish but a primer before spraying the actual paint. But you could use varnish afterwards, why not. Did not do that because this paint was a sort of metallic/silver so I was not sure about the result when using varnish.
You are not going to be able to get the original finish so I would agree with Leslie that cleaning and then spraying would appear to be the answer. Should be very similar if done properly.
Peter
Leslie: Using a rotation sander (don't know the english word) or a repaint job?
Orbital sander?
hammer_smyth: I was lucky enough to pick up a nice pair of M70s off craigslist complete with trumpet stands (one dead woofer, but replacement is on the way).
Is the replacement original?
Rich: Orbital sander?
I think you'd have to rotate the whole trumpet actually, so place it on a lathe and brush it, not sand it.
chartz: Rich: Orbital sander? I think you'd have to rotate the whole trumpet actually, so place it on a lathe and brush it, not sand it.
What about using a Dremel and its polishing kit? I have one (the polishing kit) and have never tried it on anything!
Double post again.
Trouble is, it was brushed in concentric radial passes originally (the centre being the small side of the trumpet) so it will not look like the original ones.
So the whole stand has to be rotated in some way.
Rich: Is the replacement original?
Yes. I actually got two, out of a set of M70s.
I'm thinking of installing both thr new ones and keeping my working one as a spare.
Thanks for all the replies. I live in NYC with limited access to tools or workspace. This sounds like a job too large for my toolbox so I might try and talk to a metal polisher and get a quote.
It sounds like I won't be able to achieve the orbital brushed original finish. Do you think these will look ok if I take them to a polisher and get them to work on it? I'm unsure of what kind of finish to ask for. Any recommendations?
hammer_smyth: Rich: Is the replacement original? Yes. I actually got two, out of a set of M70s. I'm thinking of installing both thr new ones and keeping my working one as a spare.
Very good. I have spares of all the drivers.
I can't help with the stands as I've never even seen them in person.
Here's what mine (untouched) look like. Actually the flashlight worsens things!
chartz—that's really helpful, thank you!
I'll report back with results.
for hand, i think ordinary metal polish would do it.I use that on many aluminum parts
My re-capped M75 are my precious diamonds.
All aluminum from B&O is anodized, this hardens the surface and protect it against oxidizing, once the anodized surface is penetrated the oxidizing occurs, to get the aluminum back to the original look the anodized surface has to be restored, meaning, polish or grind away the anodized surface to naked aluminum, polish to the same structure as B&O uses, and then anodize again. This is not possible with normal workshop means.You will have to know exactly how B&O does it (I think the procedure is patented).
What we can do is like Christian mention, polish for aluminum wheels or the like, is that does not do it, the only way is the way Jacques mention, a lathe, circular motion, and polish, grind, away until bare aluminum,
I have tried on several aluminum flat pieces, always sanding or polishing in the "grain" direction, I found that hand sanding last time with 280 to 320 grain comes the nearest I can get to the B&O surface finish. If one does that in a lathe, the speed will be faster and the grain will have to be lower to get the same result, grinding or polishing is a matter of speed, pressure and grain, change one of these and you will get a different result, also to consider is, using water, turpentine or a thin oil to keep your grinding/polishing pad free from running "full", this also will change the surface structure.
At last you will have naked aluminum, this has to be protected against oxidation, and make it easier to keep clean, this can be done with a simple car wax, but you will have to apply this every 6 to 12 months, or as I prefers, paint with a polyurethane lacquer, here you will have to have a very clean surface, use acetone to clean, after cleaning use white cotton gloves to handle the items, any finger prints will show after painting.
You can ad more layers of lacquer, but you will have to sand lightly with 400/600 grain (observe direction) between layers, and also keep your surroundings, when spraying, dust free.
Collecting Vintage B&O is not a hobby, its a lifestyle.
I am quite sure ordinary cheapset metalpolish on a tube will do it together with a cotton cloth.,, it will remove all of the black sopts and make it shine like the sun, but it is hard work for your muscles. Take beer breaks