Why does flux turn pink?

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Elow
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Why does flux turn pink?

Post by Elow »

I just put this all together and most of the flux turned pink when evaporated. It also smelled like chlorine. Is this safe to inhale? What’s the best way to clean this? I would imagine buffing would do the trick but it’s kind of hard to do that here and i have bad memories of trying to buff small and tight bends.
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bbocaner
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Re: Why does flux turn pink?

Post by bbocaner »

it's not the flux that turns pink, the flux turns the surface of the brass pink, it's acid - it dissolves the zinc out of the brass, the same way red rot does. and the heat from your torch accelerates the process. it's just on the surface and should buff off. In the tight areas you might need to rag it rather than using a wheel.
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LeTromboniste
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Re: Why does flux turn pink?

Post by LeTromboniste »

Try wrapping a long but thin piece of sandpaper or a long thin strip of leather with buffing compound around the tubing in the tight spots (wrap half a turn or one turn), holding both ends in tension and pulling them back and forth.
Maximilien Brisson
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Crazy4Tbone86
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Re: Why does flux turn pink?

Post by Crazy4Tbone86 »

I’m just trying to figure out how Elow is doing the assembly of that F attachment. I was taught to start at the bell stem and assemble the bell section backwards (bell side outside tuning slide receiver, tuning slide assembly, gooseneck, slide receiver and then bell brace). Only then do you start the assembly of the F attachment section. I worry the Elow is going to need to rebuild it again and will need to buy new parts. Just a concerned citizen.
Brian D. Hinkley - Player, Teacher, Technician and Trombone Enthusiast
Elow
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Re: Why does flux turn pink?

Post by Elow »

Crazy4Tbone86 wrote: Sat Aug 22, 2020 9:43 am I’m just trying to figure out how Elow is doing the assembly of that F attachment. I was taught to start at the bell stem and assemble the bell section backwards (bell side outside tuning slide receiver, tuning slide assembly, gooseneck, slide receiver and then bell brace). Only then do you start the assembly of the F attachment section. I worry the Elow is going to need to rebuild it again and will need to buy new parts. Just a concerned citizen.
Hopefully not, i soldered the bell to the bell brave and slide receiver and just put the valve on that to make sure everything fit.
Crazy4Tbone86
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Re: Why does flux turn pink?

Post by Crazy4Tbone86 »

That’s good.....I hope your project turns out well!
Brian D. Hinkley - Player, Teacher, Technician and Trombone Enthusiast
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elmsandr
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Re: Why does flux turn pink?

Post by elmsandr »

Crazy4Tbone86 wrote: Sat Aug 22, 2020 9:43 am I’m just trying to figure out how Elow is doing the assembly of that F attachment. I was taught to start at the bell stem and assemble the bell section backwards (bell side outside tuning slide receiver, tuning slide assembly, gooseneck, slide receiver and then bell brace). Only then do you start the assembly of the F attachment section. I worry the Elow is going to need to rebuild it again and will need to buy new parts. Just a concerned citizen.
Huh.
Being that all my works are on a modular setup, I do not do it that way. I do the attachments alone on the bench and then fit the braces to the existing tuning slide and bell. I see no reason why any new parts would be needed here.

Looks like a great start. You’ll probably decide that there are a dozen things you want different. That’s OK, that is why your 10th section will look better than your first. I just saw my first vale section for sale again in the world and one ferrule still bothers me. But I haven’t made that mistake again.

Cheers,
Andy
Elow
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Re: Why does flux turn pink?

Post by Elow »

After looking in the shop for an 1 hour, i found the tools i needed at someone’s desk. They were my tools that i bought with my name on them... i don’t understand how adults with responsibilities don’t have the brain capacity to put tools that aren’t their’s back where they found them. Anyways, buffing compound on a wick works great and i am almost finished with the project.
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Crazy4Tbone86
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Re: Why does flux turn pink?

Post by Crazy4Tbone86 »

Yes, hand wicking is great way to buff a horn. I know a tech who never uses a buffing wheel because he does not want to remove any more metal than necessary. He hand wicks everything. It is very time consuming, but it does retain more of the metal.
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elmsandr
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Re: Why does flux turn pink?

Post by elmsandr »

Looks good!

What are you planning on mounting this to?
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Amconk
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Re: Why does flux turn pink?

Post by Amconk »

Looks great! Can’t wait to see more pics of the project.
Michael Conkey
Southern Oregon Trombonist

-Besson Be944 Sovereign with Hagmann
-Holton TR-140 “monster” valve
-Modified Schiller 7B clone
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