Pink brass after soldering. Copper? Safe?

[Fingerlickin_B]

Hi folks,

I've tried searching heaps, but there is either a problem with my technique or the search function itself...

So my mate silver soldered some fittings together for the mash tun & it's pink around the solder points.

Is this just copper drawn out of the brass during heating & if so, is it safe to use? He's a plumber & seems to think so, but I want a brewing opinion.

I hope so, as the new rig is due to take it's maiden voyage tomorrow

 

[calobes]

If your decribing what im thinking of, its from the copper. Just clean as you usually would newly welded fittings and it will be ok.

If you're still unsure post up a pic and ill let you know

 

[Curly79]

Got a photo? I'm a plumber myself and I know what you mean. Pretty sure the pink stuff comes from the flux which we use when soldering copper to brass. There's no way of doing it without flux. Should only be external of the weld. Depends where it is?


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[Fingerlickin_B]

Cheers for replying guys.

Have attached a pic.

No amount of elbow grease is getting this off!

BTW, this will be inside the mash tun...

 

[Curly79]

Yeah that's what you get from flux/solder/brass. Can't tell you much else mate. Sorry. I'd imagine it would be ok after a good scrub and clean. Looks like your plumber friend has done a nice neat job too. Not too much flux.


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[calobes]

Yep absolutely fine. I weld brass fittings to copper on jobs in the food and beverage industry and all we do is flush the system before use. You have to do that anyway to remove all the flaking in the copper due to oxidization.

 

[Fingerlickin_B]

Excellent, thanks guys!

But just to be sure...you are aware this joint won't just be carrying liquid? It will immersed in the mash.

 

[calobes]

Excellent, thanks guys!

But just to be sure...you are aware this joint won't just be carrying liquid? It will immersed in the mash.

You can boil it first. I usually boil anything new to make sure its all good (if it can be boiled that is)

But honestly a good clean/flush will do the trick

 

[calobes]

You have to remember welding is HOT, alot hotter than 100°c. Your not going to damage the joint.

 

[Fingerlickin_B]

Cool, thanks again

I was more worried about flux residue being in contact with the wort, but I guess you're saying it doesn't matter...which is great

 

[calobes]

Cool, thanks again
I was more worried about flux residue being in contact with the wort, but I guess you're saying it doesn't matter...which is great

Lol, no you dont want flux residue contacting the wort, If there is any slag on the internal joint it should be minimal and will wash away when you flush it.

 

[Fingerlickin_B]

But aren't you saying the pink stuff is flux?

Now I'm confused...

 

[calobes]

It is a result of the flux.

When you weld with flux, like you do when welding copper to brass, it can create a slag. This will be washed away when you clean it.

You wont get rid of the discoloration, but it is nothing to worry about.

Sorry to confuse you, worded badly.

 

[Fingerlickin_B]

Ah, got it!

Yes there was slag similar to that when soft soldering too hot/for too long. That scubbed off

Thanks again

 

[Maheel]

drop the whole thing in a citric acid bath for an hour (or even dilute hydrochloric like 1 mins) for a quick clean.

the whole thing will go "pink" looking

but after a while it will go back to "brown" when it all tarnishes

looks like a pros work but