Brass valve fails after soldered for 5 days

[wenmang]

Hi,

I posted a question a couple of days ago about soldering the brass valve and I claimed later I was able to have it solered. But, to my surprise, it starts leaking after 5 days(I did it on last Sunday). The leak is misty but not like dripping and it flooded half of my garage. I remember one of my plumbers said, "if it does not leak now, it will not leak in future". I don't know what went wrong and why it starts leaking after 5 days. Any idea? What did I do wrong at first place? One thing which I am not sure about is that after I detect solder starts melting, should I stop heating and continue applying solder without flame or I have to keep heating the brass valve. Last time I did stop heating when melting started since I did want to overheat it. thx

[dpb]

[e-mail] wrote: ...

Because you had just enough cold solder and flux in the joint at one small point that it took a while for the pressure to force it out and for the weak point to then show up as a small leak.

What was probably wrong in your technique was not heating the joint all the way around and ensuring you flowed solder fully into the joint before removing the heat in the effort to try to be quick. I didn't see original post, but if you remove the valve seat before soldering there is little likelihood of damaging the valve body as long as you don't just heat the whole thing red hot.

You might get buy w/ heating the joint in place and flowing in some additional solder, but the best bet is to remove the pipe joint that is leaking entirely and reclean and flux and resolder the whole thing. The second benefit of doing that is you will undoubtedly be able to see what went wrong--most likely you will find the back side just didn't get solder all the way around the joint. You might also find a spot that didn't get cleaned well or was missed w/ flux so the solder didn't wick into the joint and flow well.

[Harry K]

You also must get _all_ the water out of the pipe and valve. Best procedure is to bite thebullet and remove the valve, clean everything up again and do it over.

Harry K

[wenmang]

Thanks for the reply. For last time, I did heat the joint pretty long and caused solder to melt and dropped off the ground instead of sucking into the joint. And, after removing the valve(after unsuccessful soldering), I did see the black thingy coated on the surface of pipe and inside valve joint. I assumed at that time that I heated too much and caused flux or something else oxidized and formed a coating layer that prevented sloder getting in. Next what I did was to heat the joint right at the point that solder started to melt and stopped heating and applied solder until about size of diameter of pipe was consumed.

[dpb]

All I can tell you is to heat the valve (not the pipe) enough, but not too much... :) When the valve is hot enough that the solder melts on touch of the pipe (not the flame of the torch), then it will wick into the joint automagically.

What I always recommend to newcomers to the art is to simply take a few fittings and short sections of pipe and practice several joints until one gets a feel for how long/how hot it takes. Once a few go smoothly, it will become obvious how to get it right. It has always astounded me that folks seem to think the few pennies and an hour is so expensive so they immediately want to make their first ever solder joint on a real piece of work in a difficult place to access that will cause a problem later if it isn't up to snuff. (That's not a personal slam, I didn't see the original post so you may well have done some practice joints, but just a general observation over the years of what the bulk of diy'ers approach seems to be).

And, like painting, I can't over emphasize the importance of good preparation of the jointing surfaces...

[Tony Hwang]

Hi, learning process. When solder flows, just looking at it you can tell whether it is going to be good or not.

[trader4]

"Next what I did was to heat the joint right at the

You should be heating it and then after about 45 secs, start touching the solder to the side away from the flame. If it doesn't start to melt, take it away and retry again in about 15 secs. When it starts to flow, continue heating and apply the solder around the joint.

[trader4]

Also, these solder joints are easiest to do when the pipe and the fitting are new. Since you've now tried to solder this thing a zillion times, it only gets harder to make it clean, get it fitted, etc. You never want to reuse any cheap copper fittings, like couplings, elbows, etc, unless you have to. It's by far easier to just use new ones. I know in your case that may not be possible, but it's a tip to avoid future trouble.

[Sacramento Dave]

Remove the valve clean or buy a new one, Sand the pipe and the cup on the valve,Flux pipe and valve ( don't be afraid to put flux on never to much) install the valve on the pipe OPEN the valve. Heat the pipe and the Valve ( you need to heat both) keep touching the solider to the joint, when it melts you should be able to see the solider suck in the cup. That's when you want work the heat ( flame) on the valve The solider should flow right around the joint. It sounds like you might over heating the joint . If there is any water in the pipe that is getting hot and turning to steam it will blow your joint that's why you want open the valve.

[EXT]

I have been soldering copper pipes of and on for 45 years. With lead solder, I have never had problems. The new lead-free solders are giving me problems. If it is not heated enough it won't melt into the joint. If it is over heated it floods into the joint and will not fill the void between the pipe and the fitting, with leaks developing several days later.

I have actually reverted back to old fashioned flux paste and a lead free solder that is 20 years old, it works better than the current solders they sell now.

I have always tried to build a fillet around the edge of the joint to ensure that it is sealed tight. With the small temperature range of slush that current lead free solders have, it is difficult to build the fillet.

[Michael B]

[trader4]

Yeah, where does it say that JB Weld is approved or appropriate for use on copper fresh water pipes?

[Michael B]

Let's see. Lead-based solder has been used on them since whenever. And plumbers are being careful to not lose their rolls of it now because they can't get more. And the OP is obviously having considerable difficulty getting a good bond in this_ garage_ fitting. Why don't you just invite him to call a plumber? Or use Copper-Bond, which is NSF approved. Oh, that's right, that was my suggestion earlier.

snipped-for-privacy@> > I responded to your other post and suggested Copper-Bond.

[Tom The Great]

Possible water hammer problems?

tom

[Doug Miller]

Oh, phooey -- you can still buy lead solder.

[mm]

I wanted to wait until someone with more experience like Trader confirmed what I thought, but just think about it: If you stop heating as soon as it starts to melt, it will be cooling off while the solder is supposed to be flowing all the way into the space and around the pipe. The heat has to be there until you think it has fully flowed.

It's not like some kind of food cooking where iirc one can turn off the stove as soon as the water starts to boil. (Minute Rice?) Maybe you were confusing it with that.