Problem soldering Brass PEX fitting to Copper pipe

[CountryBumkin]

I purchased some brass PEX couplers made for soldering to copper pipe.
These https://www.supplyhouse.com/Wirsbo-...X-LF-Brass-Sweat-Adapter-1-2-PEX-x-1-2-Copper when I tried to solder these I could not get the solder to flow into the joint. I cleaned both fitting and pipe with a wire pipe fitting brush and used soldering flux on both pieces. Then I heated the copper and brass fitting with my MAP torch (making sure to get the brass hot) but the solder just "rolled off" the fitting, it would not flow into the joint.

What did I do wrong?

Is there a special flux or solder for this?
I used the same flux/solder that works fine on my copper to copper joints.

 

[Reach4]

Oatey No. 95 flux worked really nicely for me.

 

[Sponsor]

 

[CountryBumkin]

I'll get some of that Oatey flux.

I wonder if I could have overheated the brass.
I read on the "flux manufacturer's data sheet" that one should heat the fitting then remove the heat, and then apply the flux. I kept the heat on the fittings the whole time.

 

[Reach4]

https://www.oatey.com/ASSETS/DOCUMENTS/ITEMS/EN/No_95_Tinning_Flux.pdf says

DIRECTIONS FOR USE
Tinning Fluxes require only a small amount of flux
applied to the joint. Clean all surfaces before soldering.
Apply small amount of flux inside the fitting and outside
of the pipe. Heat to temperature required for soldering.
Do not overheat the piping. For small diameter piping,
direct the heat near the joint.​

 

[MKS]

Search sweating no lead copper to brass copper pipe institute, I believe. It was on here before. You maybe over heating the brass.

 

[Reach4]

Search sweating no lead copper to brass copper pipe institute, I believe. It was on here before. You maybe over heating the brass.

https://terrylove.com/forums/index.php?threads/soldering-lead-free-brass-video.59322/

 

[Dj2]

Any water in the pipes?

 

[CountryBumkin]

No water in pipes.
All new, clean pipe and fittings. I think I overheated the brass. I was heating the brass first because it is larger and I thought it needed more heat than the copper, but I see now in the Video that that was the wrong way.

Is there any difference between tinning flux and soldering flux?
Or just different names for the same thing.

 

[Reach4]

Is there any difference between tinning flux and soldering flux?

Yes. Very much so. Tinning flux has powered solder in it.

 

[Jadnashua]

If you overheated the fitting, when you take it off, you'll likely see black deposits of char. You'll need to clean it thoroughly again before you can reflux and try again. FWIW, if you get the fitting hot enough, the pipe will be hot as well.

For someone who does not solder often, a tinning flux can be a big help. It literally has powdered solder in it. You heat things up enough to notice the solder in the flux has melted and you know it's hot enough to then add solder to complete the joint.

Before they began requiring a water soluble flux, I think the acid based stuff was easier to use.

 

[CountryBumkin]

Yes. I burned the flux.
I was overheating the brass fitting.

The video above says to Not heat the fitting first. Heat the copper so the part of the copper inside the brass gets hot enough (video says the air space between copper pipe and fitting does not allow proper heating of the pipe if the heat is only directed to brass fitting). That was my mistake.

Also, I'm going to get some Oatey 95 and some Tinning Flux. Possibly my flux was too old or the wrong type (its so old that I cant read the label).

 

[Reach4]

Oatey 95 is tinning flux.

 

[Flow&Go]

I've also found on these that sand cloth helps as opposed to a wire brush. I make sure to hit the shoulder of the fitting pretty good with the sand cloth and it helps it take.
Also Turn the torch down a bit and take an extra minute to let it heat up evenly, when you get after it with the torch really hot it can heat the copper and flux up too much before the brass evenly heats

 

[FullySprinklered]

With the lead-free brass you may have to wave the flame around a bit over the joint once it gets hot.

 

[Reach4]

Then I heated the copper and brass fitting with my MAP torch

Sounds like the propane torch may be the tool of choice next time.