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Modeling in General
General discussions about modeling topics.
Cleaning brass
Stillhawk
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Posted: Saturday, May 21, 2011 - 06:18 AM UTC
I had to stop working on models for awhile due to health problems, and now that I'm back, upon opening an unfinished kit, I find that some photoetch I had been working on has now developed a bright green granulation. How do I remove it? As a side note, it's also blackened from the heat of the soldering iron, which is less of a problem because I can simply sand it off with fine sandpaper, but if there's a simple way to remove it, it would be helpful. Many thanks.

Michael
mauserman
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Posted: Saturday, May 21, 2011 - 07:15 AM UTC
I wouldn't worry about it since it's going to be painted anyway.
retiredyank
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Posted: Saturday, May 21, 2011 - 08:01 AM UTC
I agree. Don't sweat it, just paint it.
jon_a_its
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Posted: Saturday, May 21, 2011 - 10:16 AM UTC
Erm...
I would sweat it... The black is soot & the Green is CORROSION, neither will help paint stick.

One of those fibreglass pens used for cleaning electrics will help shift a lot,
A bath in Vinegar, (rinse asap) will shift a lot more, finish with fine wire wool if needed, & prime with a suitable primer, I favour Vallejos' Polyeurathane, or Mr Surfacer
Stillhawk
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Posted: Saturday, May 21, 2011 - 02:36 PM UTC
Thanks for the advice. I'm soaking them in vinegar now. The darkening I referred to doesn't appear to be soot, though, but an actual discoloration of the metal. As to the corrosion, just a few minutes in vinegar had made most of it disappear, though I intend to leave the parts in for a good, long soak. So far I haven't found one of the fiberglass pens you mentioned, but then I have probably just not looked in the right place. Thanks again.

Michael
Jessie_C
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Posted: Saturday, May 21, 2011 - 07:24 PM UTC
Those of us of a certain age and military background will remember Brasso. One tin of this stuff will clean a lifetime's worth of photoetch.

J
vonHengest
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Posted: Saturday, May 21, 2011 - 07:24 PM UTC
I agree with Jon, that sounds like corrosion which will give you problems now if not down the road. I've had to deal with several kinds of metal oxidation and non of them accept paint. You can paint over it, but it will continue to grow underneath and after a time the paint will start flaking off. You made a good choice be being safe and getting rid of it.

Steel wool or mild sanding sticks will suffice to finish the job. If you're hard pressed on finding one of those pens then you should look at a dedicated computer and electronics supply store.
jon_a_its
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Posted: Saturday, May 21, 2011 - 10:08 PM UTC

Quoted Text

Those of us of a certain age and military background will remember Brasso. One tin of this stuff will clean a lifetime's worth of photoetch.

J



Ahhh... Don't you just love the smell of... BRASSO in the morning.....

The "Certain Age.... " also resonates,

I got my fiberglass pencil from a

Well-Known auction site

but any electronic parts store should carry them, & remember, other vendors are available, shop around!

Don't leave things soaking too long, there might not be much left!
Stillhawk
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Posted: Sunday, May 22, 2011 - 03:52 AM UTC
Thanks guys. I appreciate the help.
Jessie_C
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Posted: Sunday, May 22, 2011 - 04:14 AM UTC

Quoted Text


Ahhh... Don't you just love the smell of... BRASSO in the morning.....



"I love the small of Brasso in the morning...

...it smells like...THE SERGEANT'S COMING!!"

J
jon_a_its
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Posted: Sunday, May 22, 2011 - 10:15 AM UTC
Ten-Hut!
bondova
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Posted: Tuesday, May 24, 2011 - 07:55 PM UTC
great
WallyM3
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Posted: Wednesday, June 01, 2011 - 12:11 PM UTC
This is difficult to accept, but disolve two tablespoons of powdered citric acid and a couple of drops of dishwashing detergent in a quart of warm water. Depending on the depth of the vertigris, you can soak from 15 minutes to overnight. This not only cleans the brass, it passifies the metal so that it resists future corrosion.

This is a common practice amongst metalic cartridge reloaders and I have used it on tens of thousands or cases this year alone as well as brass ashtrays and other odd stuff.

Brick red or copperish colored spots indicate areas where zinc has leeched out and should polish away , though it's not necessary to do so. (It is a good test to determine the soundness and safety of a cartridge case.)
pirozzi
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Posted: Friday, June 03, 2011 - 06:06 AM UTC
I reload rifle cartridges and the way to make brass look like new is to tumble it in ground walnut shells. It comes out bright and shiny and will remove any discoloration or deposits.
WallyM3
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Posted: Friday, June 03, 2011 - 06:13 AM UTC
I tumble in a vibratory unit once the cases are dry (blend of corn cob, walnut and rice, with Dillon treatment), but I didn't think that PE could withstand the mauling.

The citric acid treatment doesn't leave the brass as shiny as I like for reloading, but it won't get any cleaner.

Tumbling actually leaves a slight, dusty residue which doesn't hurt anything, but might cause problems with paint adhering.

And I used the term "passifies" when I should have said "passivates". Mea culpa.

2, please.
rebelsoldier
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Posted: Wednesday, June 08, 2011 - 08:10 PM UTC
use catsup to caot it and wipe down after about ten minutes, and then polish with dry cloth after rinse. failing that, ahhhhhh, the smell of brasso in the morning!
lukiftian
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Posted: Saturday, June 11, 2011 - 01:45 PM UTC

Quoted Text

Erm...
I would sweat it... The black is soot & the Green is CORROSION, neither will help paint stick.

One of those fibreglass pens used for cleaning electrics will help shift a lot,
A bath in Vinegar, (rinse asap) will shift a lot more, finish with fine wire wool if needed, & prime with a suitable primer, I favour Vallejos' Polyeurathane, or Mr Surfacer



Like Jon, I use a fibreglass pen. It's good to use whether you have mucky etch or not because it gives the paint some tooth.
lukiftian
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Posted: Saturday, June 11, 2011 - 01:47 PM UTC

Quoted Text

I reload rifle cartridges and the way to make brass look like new is to tumble it in ground walnut shells. It comes out bright and shiny and will remove any discoloration or deposits.



Wouldn't that be a bit hard on a flat sheet of PE? Interesting idea, though.
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