# Flux after sweat



## marc76075 (Nov 24, 2010)

hey guys, I thought i would see everyone's opinion on this

Do you flux after you sweat? I was always taught never to do this, and i can see why.
I hate using a burnt flux brush, i think its bad for the pipe(just my opinon), and i think its a lazy way to get "clean looking" joints.
so are you for it? against it? and why


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## easttexasplumb (Oct 13, 2010)

Flux goes on before sweating begins, I like to let the fittings cool down naturally then wipe off any left over flux with a small towel.


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## john_mccormack (Feb 27, 2010)

No, I wipe while the joint solidifies and is still hot. If that isn't enough, using a damp rag seems to steam the crud off fairly well.

I've seen people use the flux brush after and the joint still needs to be wiped, so I don't see any difference. I have seen the joint smeared with melted plastic when guys use the nylon brushes, though. It looks great!:thumbsup:


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## marc76075 (Nov 24, 2010)

easttexasplumb said:


> Flux goes on before sweating begins, I like to let the fittings cool down naturally then wipe off any left over flux with a small towel.


come on east, have a little more faith. I know flux goes on before, and i wipe joint with a rag after


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## PLUMBER_BILL (Oct 23, 2009)

marc76075 said:


> hey guys, I thought i would see everyone's opinion on this
> 
> Do you flux after you sweat? I was always taught never to do this, and i can see why.
> I hate using a burnt flux brush, i think its bad for the pipe(just my opinon), and i think its a lazy way to get "clean looking" joints.
> so are you for it? against it? and why


&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
I always have a can of flux close to the joint being soldered. If it dosen't look right and little flux on a hot joint works wonders.

As to burning the brush that does not happen unless you don't take the flame away. But that time the joint is too hot anyway.


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## Airgap (Dec 18, 2008)

I don't...


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## plumber666 (Sep 19, 2010)

Wouldn't occur to me to do that.


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## RW Plumbing (Aug 16, 2010)

If there is some dirt or something on the solder, I usually hit it with the flux brush and then I will go around again with the solder. Works pretty well to get nice joints. Who cares if you burn a brush anyhow? Those are like .35 cents each.


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## user2090 (Sep 26, 2009)

I used to do that, and I believe it contributed to me having a long run of problems with joints. I quit doing it and just make sure I get a good turn of solder around the joint, or as it said in my plumbers manual a fillet. 

Since I made the change soldered joint problems are minimal.


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## greenscoutII (Aug 27, 2008)

No, not in general practise I don't. Slathering on extra flux just makes for a crappy looking joint even if you do wipe it. Plus, in my experience, too much flux is just as bad as too little. Like Indie said, I too think it will contribute to leaks. The reason why is that too much flux boiling out of a joint allows the solder to boil out too...

Just my two cents though......


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## RW Plumbing (Aug 16, 2010)

I never USED to do it. When I was using good old oatey #5 flux. Now it's code here that you have to use water soluable flux on potable water systems. I hate that crap. It never seems keep the crud out of the joint as well as #5. Now I do the flux thing for a good looking joint.


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## SewerRatz (Apr 25, 2009)

Once you applied the solder to the joint, you are not supposed to wipe it or add flux to it for it can and will introduce contaminants to the soldered joint. You are only supposed to wipe the joint clean after the solder has cooled down.


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## beachplumber (Feb 7, 2010)

I don't normally hit with flux after solder.
I have worked with guys that did, becaused they had to high of heat.
Normally I hit it with a damp rag. Though I don't do much soldering around here


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## pdxplumber (Nov 21, 2009)

My copper box sits in the back corner of my truck. I can't remember the last time I had to do any significant soldering. I used to brush my hot joints with flux to make them look clean and shiny, but now I just moderate the heat and try not to burn the fitting too much. However I will always prefer a fully soldered joint to a pretty joint, especially in a crawl space.
BTW, I just gave somebody a repipe bid in pex. They asked about copper and I gave them options with M and L and mentioned K just as customer education. Now he wants to get a bid with type K for the whole house!? That would be a first for me.:blink:


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## Optimus Primer (May 20, 2009)

marc76075 said:


> hey guys, I thought i would see everyone's opinion on this
> 
> Do you flux after you sweat? I was always taught never to do this, and i can see why.
> I hate using a burnt flux brush, i think its bad for the pipe(just my opinon), and i think its a lazy way to get "clean looking" joints.
> so are you for it? against it? and why


Frawley is that you? Anyway no I dont wipe flux on my freshly solder joint. Maybe if I'm unsweating something that's been there for a couple years or so.


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## Tommy plumber (Feb 19, 2010)

The only time I use the flux brush while soldering is if I have a vertical joint that I can't wipe a drip with my dry rag; I'll use the flux brush to 'flick' the annoying drips away. The joint is in a tight spot.

Another trick I like is to lighly spray the copper with a spray bottle after soldering; it sizzles and cleans the joint well, then a little later I use the rag to clean it too.


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## Redwood (Sep 8, 2008)

Nope but I've seen many that have been...

A few years down the road you can see corrosion that looks like it was brushed on...:whistling2:


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## JK949 (Mar 18, 2009)

I let the solder solidify first, then brush the fitting. Spray with soapy water and wipe clean.


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## JK949 (Mar 18, 2009)

pdxplumber said:


> BTW, I just gave somebody a repipe bid in pex. They asked about copper and I gave them options with M and L and mentioned K just as customer education. Now he wants to get a bid with type K for the whole house!? That would be a first for me.:blink:


Hope you have one of those Milwaukee Robo cutters. K is a pain to cut.


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## PlumberDave (Jan 4, 2009)

I use Everflux(water soluble) and no matter what I have tried the stuff leaves black burnt marks/sploshes and if I don't hit it with the 2nd brush I have to scrub it off. Never had that issue with Laco before the water soluble change.


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## Moose Down (Nov 4, 2010)

:no: I asked my boss man about this about 3 weeks ago, his reply was "sure if you want me to give you a swift kick in the n.ts after"


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## bolivar (Dec 9, 2010)

I have found over the years that the combination of changes in the solder and fluxes have made it more difficult to get great looking joints. In practice, I cool the joint with flux and then wipe it off. I love using a dry rag to wipe down the flux. As one of you stated, it is great to allow things to cool naturally, and this is the best. However, in many situations, like repair work, you want to move on and avoid fire hazard by cooling it off quickly. Burning up fitting brushes is the least of my worries. I buy them a dozen. While I use a damp cloth to cool at times, I believe cooling it with flux is a gentle lowering of the temperature before using a damp cloth. I believe cooling directly with a damp cloth may damage the joint, causing stress lines in the solder.


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## ap plumbing (Nov 9, 2010)

I do


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## Qball415 (Nov 20, 2010)

W-D 40 on rag when cools down wipe it down beautiful looking fittings!:thumbup:


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## Jeff (Oct 12, 2010)

no, but have on rare occasions. Best thing to wipe a joint with, while still hot ,
is a piece of insulation. The insulation is light and wont bump the joint when wiping.


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## Redwood (Sep 8, 2008)

bolivar said:


> However, in many situations, like repair work, you want to move on and avoid fire hazard by cooling it off quickly. Burning up fitting brushes is the least of my worries.


Try these they work! :whistling2:



















If you still worry about burning down houses when you use them maybe you should check out SharkBites...:laughing:


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## easttexasplumb (Oct 13, 2010)

The cool gel is pretty awesome stuff :thumbsup:


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## CSINEV (Aug 6, 2010)

I don't use a flux brush after I'm done soldering, I don't use a wet or damp cloth to wipe. If done correctly you don't need to wipe, more then a dimple is a waste of solder. a quick flick with my cotton glove and the dipple is gone and a clean joint is left. Then I leave it alone to cool on it's own and never touch it while cooling down. Guys always use WAY WAY to much solder and most times to much heat too. If preped and heated correctlly the solder will flow quick and you done with no drops at all. This is a skill that is learned over time and you must be willing to take your time, you can't rush a good joint.:thumbup:


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## Titan Plumbing (Oct 8, 2009)

A half inch of solder for a 1/2" fitting and so on is all you actually need. To force it in and let several drops drip off is a waste of $26. a pound solder and does nothing to improve the quality of the joint. Same goes for flux, a light coating in and out and twist if you can and you're good to go.


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## greenscoutII (Aug 27, 2008)

Choctaw said:


> A half inch of solder for a 1/2" fitting and so on is all you actually need. To force it in and let several drops drip off is a waste of $26. a pound solder and does nothing to improve the quality of the joint. Same goes for flux, a light coating in and out and twist if you can and you're good to go.


Yep, couldn't have said it better myself.......


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## plumber p (Sep 19, 2010)

I agree with letting the joint cool then wipe flux off.


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## Epox (Sep 19, 2010)

Redwood said:


> Try these they work! :whistling2:
> 
> 
> 
> ...


Cool Gel works nicely just keep applying to keep good layer if several joints to do.


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## Redwood (Sep 8, 2008)

mpsllc said:


> Cool Gel works nicely just keep applying to keep good layer if several joints to do.


That fire shield works good too!
Its a lot better than the smoke pipe some guys use. :laughing:

Red hot tin is red hot...:whistling2:


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## U666A (Dec 11, 2010)

Just a thought... The vapours from flux are highly toxic. My teacher from basic tradeschool (whom I still have a great deal of respect for) advised against this. I simply don't do it.


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## ranman (Jan 24, 2010)

I have a fire shield love it. 

as for as cool jell. I spray myself down with it daily:laughing: its hard it be this cool



mpsllc said:


> Cool Gel works nicely just keep applying to keep good layer if several joints to do.


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