Failed to solder an easy joint

[Bob from accounting]

It has been been a few months since I solder a joint.
Well I needed to replace the water heater ball valve that was rusted and leaking from the corroded packing nut.
I cut that valve off of the 3/4" line above the water heater.
After I cut it off I noticed there was a drip of water, a small amount ever 8 seconds falling vertically out of the pipe. drip..8 seconds. drip. 8 sec drip..
I shoved some bread about 6" up the vertical line and it stopped completely giving me time to work.
I began to solder a threaded 3/4" coupling onto the end of the pipe using map gas.
I have solder about 30 joints in the past and felt like this was no problem compared to the 1" ball valves and joints that take a little longer than this 3/4" threaded coupling should take. I still am learning so I knew there were risks but I felt that I had solder enough joints to know how to prep the joint and pipe, flux, and heat a joint properly and what a good joint looks like and how much time it take to heat before the joint can receive the solder.
After fluxing and heating the joint and pipe up, each time I applied the solder it just crumbled away and I knew this was not good. The torch covered all around joint for enough time to heat this up evenly, in fact I felt that I had the torch on the joint too long it was beginning to blacking and burn off the flux and the solder never melted to fill the cup. So I shut it all down after about (60 sec) and cut the bad blackened burned joint off instead of continuing.
I am very disappointed, not sure what I did wrong, clearly it is me, but just feel defeated and applied a sharkbite hose there for now to get water going.
Eventually I will need to get that sharkbite out of there before it breaks down but just wanted to vent my disappointment on messing this up. Bummed out.

 

[Jadnashua]

If there is ANY water on the joint, that will keep the metal at a lower temperature, making it impossible for solder to flow. If you overheated it, that can prevent it from flowing, too. Since I don't solder all that often, I've found that a tinning flux can help...there's powdered solder in the paste. Once the joint is hot enough, it is readily apparent that it's hot enough as you can see the solder in the flux melt, as that melts...then, you can add some more to finish up the joint.

When heating it, did you notice any steam or hear any water boiling?

When it's a pain to stop a small drip, sometimes, I'll switch to a compression fitting versus a soldered one. Worst case, maybe a Sharkbite valve or fitting. I ended up using one of those when I needed to change my unit shutoff in my condo. I was only able to shut the main water off for a short time, and with ten units potentially dripping into my now open pipe, it was never going to easily dry out enough to solder anything. Bread can work, but there are commercially available water stoppers that will eventually dissolve more completely and not potentially gum up things.

 

[Sponsor]

 

[JohnCT]

As Jim correctly said above, water in the pipe is a big problem - change of state and all that. A little water absorbs a lot of heat.

You can add more bread than you think might be prudent, and push it back farther up the pipe (don't use crust). In addition, the pipe *must* be scrupulously clean (don't shortcut here) and of course have a thin coating of flux *on both sides*.

MAP gas is great, but it can overheat a joint rather quickly and burn off the flux causing oxidation to start. Once that happens, the opportunity to flow solder is gone until the scorched section is either cut out or sanded down to clean copper and refluxed.

What I do is lightly heat the valve and then the pipe about 8" down from the joint. A cold piece of copper will suck heat off the joint, not as bad as water, but enough to make your life miserable. Once the pipe is preheated, turn up the heat on the joint and watch for that window where the solder flows.

Lastly, installing a full flow valve will allow you to use this tool like a Jet Swet.

John

 

[James Henry]

Was the valve open? Black is a sign of over heating.

 

[Terry]

Was the valve open? Black is a sign of over heating.

Yes, black is not good when you're soldering. I touch the solder to the joints early on to test the waters so to speak.
If it's on the cold side and still dripping I make sure that something lower is open for it to drain down and if it's still dripping I open the high stuff too so that that all of it drains down completely too. I solder with the valve open and always make sure that there is something open to let hot air escape so that the last joint soldered doesn't blow a hole in the last solder joint. And I use Mapp all the time, my favorite.

 

[Fitter30]

Push the bread at least 3" + if possable. Do not touch the copper with bare fingers the oil on your skin will make the solder not flow correctly. Failed joint by touching it after taking one apart can see a finger print on the copper alot of times.

 

[Bob from accounting]

Hi, yes I was using tinning flux, the bread was jammed up there past the joint about 6"-8". The drip was about once every eight seconds.
So the amount of water was so small and was all stopped about 3mins prior to soldering it. The bread could have lasted hours before it seeped through, so there was no water. There was no steam when I heated it as there was no water near the joint as it had been stopped and dried off.
When I evenly sweat a joint I evenly preheat the pipe and fitting individually with map gas. So heat the pipe a little bit than go and direct the flame onto the fitting after heating the pipe up and down.
I had fluxed both ends, cleaned, deburred both ends. Since this was a vertical fitting I had a small 1/8" steel pole under the fitting so that it did not drop off the pipe when heated up. It was holding it up.
This was not a valve this was just a threaded coupling which I would later screw the valve onto, so it was just a little basic fitting not a valve.
Basically this was so easy, and somehow it never seemed to get hot enough yet turned black and scorched.
I realize this was my fault and a learning experience, just needed to vent here.
Not sure what I would do different as I feel I was covering my basis here but I know it was user error here. I have a sharkbite hose in there now temporarily, I would like to give it another go soon.

 

[Terry]

Push the bread at least 3" + if possable. Do not touch the copper with bare fingers the oil on your skin will make the solder not flow correctly. Failed joint by touching it after taking one apart can see a finger print on the copper alot of times.

I've almost never used bare fingers while fluxing. Just one time is too much. I see that on some of the funky videos out there, where the guy looks like he picked up a torch for the first time in his life and made a video that's being watched thousands of times. I shake my head in horror watching some of that stuff.

GLOVES always when soldering and assembling fittings with flux.

 

[Terry]

We've all had leaks at some time.
Below I was removing a control valve and both shutoffs were to remain closed. I installed a tee where I could install a valve to let hot air out while soldering. OK, I threaded that on after my soldering. It was 1-1/2" copper in a large car detailing business. The top coupling was a slip coupling without stops.

 

[wwhitney]

When I evenly sweat a joint I evenly preheat the pipe and fitting individually with map gas. So heat the pipe a little bit than go and direct the flame onto the fitting after heating the pipe up and down.

My technique is typically to heat just the solder cup of the fitting from one side, and apply the solder to the solder cup end 180 degrees away from the flame. That way I can keep the solder near or on the solder cup, testing frequently to see when the heat has spread around the cup. Then once the solder starts melting there, I remove the flame, and run the solder around the cup, 360 degrees. If it seems to be taking too long, I will sometimes swap sides in the middle of heating, where possible.

Have I been doing it wrong all these years? : - ) I did have one joint I had to redo on the last house I did (where only the cold water trunk was copper, plus the shower valve outputs).

Cheers, Wayne

 

[Jeff H Young]

good tips! Evidently joint was overheated, different brands of flux behave differently . I've got my favorite everflux plastic tub white with I think red lettering abd always a blue lid. Stuff many claim is nasty turns green if you fit up and let it sit a short while (depends on weather humid is worse) hard on skin , horrible on scratches cut, in the summer heat you may breakout with red itchyness on any part of body exposed. other than that Its great1 Ha Ha. others burn at low. temp leaving the black and solder wont take. but with experiance and cleaning fittings and pipe many work good.
I started a new technique very recently where ill install a mip adapter and slip a smaller pipe inside and run shop vac just leave it run or turn off when burning. I used to blow out with CO2 but I don't carry the bottle much anymore and vac it out. Draining water down is way to go kind of wastes a lot of time opening up bunch of faucets. sometimes you gotta loosen the meter union and let water out there too if the stop isn't good

 

[DIYorBust]

I've almost never used bare fingers while fluxing. Just one time is too much. I see that on some of the funky videos out there, where the guy looks like he picked up a torch for the first time in his life and made a video that's being watched thousands of times. I shake my head in horror watching some of that stuff.

GLOVES always when soldering and assembling fittings with flux.

Terry, what gloves are you using to solder? I have a slowly fading burn from a few months ago where a drop of solder landed on my 8 mil nitrile gloves. I was up on a ladder with my tochh and couldn't do much about it fast enough. Sometimes I use leather or cotton work gloves. It seems like the nitrile would be ideal for fluxing, and the leather best for soldering, but who wants to keep changes gloves? Should I do the leather over the nitrile?

 

[DIYorBust]

If the solder is turning black, my guess is that it isn't an issue with water. The pipe is getting hot and burning the flux. I usually solder with propane as DIY, though I've used the MAPP when it was around. I'm usually not doing a huge volume and the extra time in right temp zone makes it a bit easier to make nice joints. I also use silver solder. It's a bit more expensive, but usually not much so on the cost of a plumbing job, and it has a little better pasty range for making a nice joint. Non lead solders melt at a higher temperature, and thus the plumber must judge more accurately when the joint is hot enough to solder but not too hot the burn the flux, and the propane and the silver make that a bit easier for me. I actually like to use the silver because I don't like the idea of 5% antimony, which is toxic, but apparently still safe, in my pipes. But it also is a bit easier to work with sometimes.

 

[James Henry]

Terry, what gloves are you using to solder? I have a slowly fading burn from a few months ago where a drop of solder landed on my 8 mil nitrile gloves. I was up on a ladder with my tochh and couldn't do much about it fast enough. Sometimes I use leather or cotton work gloves. It seems like the nitrile would be ideal for fluxing, and the leather best for soldering, but who wants to keep changes gloves? Should I do the leather over the nitrile?

Brown cotton gardening gloves.

 

[Terry]

Something like these are nice. Milwaukee cut level 1 gloves.

 

[Reach4]

If you want a glove not made with nylon, polyester, or other synthetic that can melt easily, consider welders gloves. Maybe over-cautious.

 

[DIYorBust]

I like the gloves Terry mentioned. They are also cut resistant. I've never been cut, but I could imagine it happening quite easily. I definitely find a loss of dexterity in the nitrile dipped gloves though.