Etching Brass for Painting

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timmy wheeler
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Re: Etching Brass for Painting

Post by timmy wheeler »

Would soda blasting work? Timmy
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rkcarguy
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Re: Etching Brass for Painting

Post by rkcarguy »

Soda is a bit of a debate. Some love it, others say that the parts need to be washed afterwards with a vinegar/water solution or the paint peels. Many automotive paint companies won't honor their product warranty if the car/panels were soda blasted.
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Bill Shields
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Re: Etching Brass for Painting

Post by Bill Shields »

Chilled shot is really the best as harold said...but my booth is currently filled with new glass beads

Right wrong or otherwise I am depending on the ospho to provide the stiction based on jack b's insight.

So far so good....
Too many things going on to bother listing them.
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Harold_V
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Re: Etching Brass for Painting

Post by Harold_V »

Bill Shields wrote: Fri Mar 12, 2021 9:18 pm Chilled shot is really the best as harold said...but my booth is currently filled with new glass beads
Well, that's not exactly what I said. Chilled shot is great for some things, but it's not any better than glass bead, as it doesn't cut, so instead of creating tooth, it tends to blend and smooth the surface instead. Sharp abrasive is the best choice, as it increases surface area as well as cleaning well. Much better "tooth" than bead or shot.

H
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LIALLEGHENY
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Re: Etching Brass for Painting

Post by LIALLEGHENY »

I was told this many years ago from a friend whom owned a body shop, once you have the brass cleaned up, apply several light /dust coats of etching primer.....it apparently will adhere better than a single heavier coat.

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mklotz
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Re: Etching Brass for Painting

Post by mklotz »

Harold_V wrote: Wed Nov 18, 2020 2:59 am
... If you must add water, be certain to add the acid to the water, all the while stirring constantly. ...
The mnemonic rhyme I learned was:

Add acid to water
Like a fella oughter

It's been decades since I worked with acid but the rhyme sticks in my memory. That's probably why, in the days before widespread literacy when information was transmitted verbally, rhyme and song were common ways to remember a story.
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Harold_V
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Re: Etching Brass for Painting

Post by Harold_V »

I worked with nitric, hydrochloric and sulfuric acids daily when I refined precious metals. Nitric and hydrochloric are forgiving ---- you can pour water to either of them with little consequence, but not sulfuric. It is difficult to mix with water even when pouring the acid to the water, due to the exothermic reaction. Without stirring, one experiences local heating and boiling, resulting in some serious spatter. I shudder to think what would happen if water was poured to the acid. An instant steam explosion with horrible results, to be sure.

I recall hearing that one pours the acid in to the ocean, not the ocean in to the acid. Anything that reinforces the idea that you can be seriously harmed if you don't understand the rules.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
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