Water Heater soldering questions

[Jason1]

Hello all,

When soldering 3/4" copper pipe to connect a water heater.

1. Should you open the nearest water valve to allow the hot air to travel up to avoid blowing out the solder from the joints?

2. Should you also open the nearest faucet, both hot and cold to further allow the hot air from soldering a way out?

3. When soldering next to black steel gas lines should they be covered with sheet metal 26 gauge to protect from the flame possibly coming in contact with the gas?

4. How do you clean the excess flux off the pipes after you are done soldering?

5. What are the most important newbie mistakes to avoid when connecting a water heater for the first time with soldering the copper pipes?


Thank you all in advance.

 

[Terry]

1. Soldering needs to be done in an open environment. A sealed line will blow out the joint.
3. I would like to think that the gas remains in the black pipes. How close are you talking about? Normally the water and the gas have pretty good distance between.
4. I keep a small towel handy for wiping the pipe and joints. I often use a spray bottle first to reduce the burns that I used to get touching hot pipes.
5. I like to solder the connection that will fit to the water heater first, and then assemble it to the water heater.

 

[Sponsor]

 

[John Gayewski]

Use a cotton towel or rag to avoid melting some synthetic bs to the pipe.

The hot air your talking about would likley be steam. Steam expands to 1700 times its size as water. One drop of water becomes the size of 1700 drops of water instantly. So yes you need to have a path for the steam to take. Or don't make any steam.

Use only enough flux to lightly coat the pipe and fitting. You should have to look close to make sure you got enough flux on the pipe and fitting.

Your flowing liquid metal into the joint and liquid flux out of it simultaneously. You want all of the flux to flow back out. If you use a lot of flux it will run all over the pipe and get trapped in the joint, which leaves voids or worse "thin seals" that will break deer time. . When you're solder becomes liquid it will want to follow the path of other liquids. If you have flux everywhere its harder to keep the solder from running everywhere.

Heat control is the most important part. Don't over heat. Dissimilar metals (copper and brass) heat at different rates touch both (with the solder) to see if they are hot, don't just rely on the pipe being hot enough, but the valve staying below melt temp. This will keep the solder from bonding to the valve (brass)

 

[Fitter30]

After cleaning the copper with sand cloth don't touch the clean joint with your bare hands oil from your skin can ruin the connection wear jersy gloves. Flux doesn't remove the oil.

 

[Jason1]

Thanks for the replies, great pointers. Definitely things a learner could miss.

There is a black steel 1/2" gas pipe that runs vertically along the water heater and is about 5 inches from one of the solder points for the water line. The valve feeding that pipe is shut off and I'll cover the pipe with sheet metal just to be safe.

Is this a good example of how to solder properly:

How common is it to add extra flux to the pipe while soldering to make the solder flow better into the joint? In practice, do you need to do this on 3/4" copper pipe or should the initial coating of flux be enough?

Thanks.

 

[Terry]

How common is it to add extra flux to the pipe while soldering to make the solder flow better into the joint? In practice, do you need to do this on 3/4" copper pipe or should the initial coating of flux be enough?

Thanks.

The initial fluxing is all you need. Sometimes wiping a bit more on is more for cooling the joint. I keep the spray bottle handy, though you also don't want to cool a joint too quickly.

 

[John Gayewski]

I haven't watched the video, but if I'm seeing the initial picture right, and he's wearing plastic gloves. It's not a good example. Lol

 

[Terry]

I don't like using a rag on the joint until it's cooled some, bumping a still hot fitting can cause a leak. Framers banging on my walls were bothersome. Hey dude, wait a moment!!

Dang he has a lot of old tools in that video, it's like a museum. He gets the job done though.

 

[John Gayewski]

Watched the video. I'm betting the gloves are leather.

He does what a lot of people do. It works for them. Not 100 percent correct.

You start soldering at the bottom of the horizontal pipe. Fill the bottom of the cup. Then work up both sides. Then the top. Starting at the top like he did will leave voids. I can guarantee if you cut that joint down the middle (long ways) and then hammer the pieces apart and inspect the joint there will be voids.

That said it probably wouldn't leak for years.

I recently found a 44 year old sweat joint that just decided to leak one day. I could tell they didn't fill from the bottom. There was one drip on both sides at 5 and 7 o'clock that didn't make it to 6. Thin seal.

Also the thing with the wiping. He did it too soon as said above.

Demonstrating on 1/2 and 3/4 inch pipe probably doesn't give enough of an example or time to show how things flow and heat. If I were doing a demonstration I would use 2"and larger to show how it should flow and heat. A lot of people use map gas and the huge torches from Lowe's. Those are too hot for small pipe in my opinion. For small pipe with hot gas your should use a small torch. Or cooler gas like lp.

 

[Terry]

I've been soldering from the top down, went eight months without a leak.
That being said, if you don't heat the pipe and fitting evenly, it doesn't matter, you going to have solder in stripes and not 100% around the fitting. A cool side won't flow.
I was taught bottom of joint first, but I changed when someone said the other way worked too. That being said, the main thing is, don't get leaks.

The video showing heat on only one side was bugging me.

 

[Fitter30]

Always try to cap a joint and how I miss 50/50

 

[Jason1]

Thank you all.

For a beginner learning to solder, is propane or map gas better for 3/4" copper pipe?

Which gas gives you more leeway in making mistakes as you solder?

 

[John Gayewski]

Propane.

 

[Sylvan]

Always try to cap a joint and how i miss 50/50[/QUOTE


Not a great idea as 50 /50 is NOT lead free

If you feel that your soldering has a lot to be desired think about buying

https://www.supplyhouse.com/Hercules-10210-1-2-lb-Swif-95-Solder-Flux-Paste-w-brush


A solder joint is easy to make as long as the fitting and tubing is clean and knowing about capillary attraction (action) you first heat the tubing then the fitting and the alloy will flow upwards to the fitting in a vertical joint

When soldering TP Copper for example knowing brass requires a lot more heat then tubing always heat the fitting then the tubing and back to the fitting to draw the alloy in

By the way I taught my daughter to solder without using 50 /50 and she was 5 years old and the water lines are still inside the walls over 36 years

FYI if any home inspectors or anyone with any knowledge sees a joint with lead they can fail the inspection as the safe water drinking acing act of 1974 was in came into effect


The fitters of local 638 used

https://www.supplyhouse.com/Hercules-10210-1-2-lb-Swif-95-Solder-Flux-Paste-w-brush


Without cleaning the copper or the fittings and decades later the joints failed on the heating and cooling coil connections

ALL tubing and fitting has to be cleaned and a wire brush is much better then "sand cloth" as emery cloth can leave particles behind


https://www.airgas.com/product/Tool...GUE4eI6sNCmXiTKSk_yJPDsP78wA3MtAaAgROEALw_wcB

 

[Sylvan]

Thank you all.

For a beginner learning to solder, is propane or map gas better for 3/4" copper pipe?

Which gas gives you more leeway in making mistakes as you solder?

Mapp is hotter and is slightly safer to use

 

[Jason1]

Mapp isn't available anymore, it's propane or map/pro at the box stores.

 

[Sylvan]

https://www.autozone.com/test-scan-...4hEKl24CiXzV55X8uk8aAtlrEALw_wcB&gclsrc=aw.ds


https://www.google.com/search?q=where+to+buy+MAPP+gas&gs_ivs=1&dlnr=1&sei=RbBQYYrRBcGHggeRyp2ABA


Personally I use Acetylene and swirl jets and I can braze copper up to 6" with no problem

 

[Jason1]

Mapp and map/pro are different gases.

Map/pro is what you can buy now, not as hot as the original Mapp:

https://en.wikipedia.org/wiki/MAPP_gas

 

[Sylvan]

Mapp and map/pro are different gases.

Map/pro is what you can buy now, not as hot as the original Mapp:

https://en.wikipedia.org/wiki/MAPP_gas

I never used used Mapp my employees did as holding a hand tank does not look professional

Same reason I never used PVC other then for a chemicals such as Chlorine

I use either an MC tank (10 cu ft acetylene) or a B tank 40 CU F Acetylene as I can use a difference tip depending on the size of the fittings

The only time I use Propane is for melting lead for XHCI or roof drain installations caulked joints

Acetylene with the correct torch produces 4,200 DEG F and with Oxyacetylene almost 6,000 deg F

Years ago I used to teach welding / brazing classes not stick or Mig just Oxyacetylene

Good old days

One of my old shipmates stayed in and retired as a warrant officer

He and I used to take the Captains gig out of New Port RI and go fishing or follow the America's Cup race in the late 1960's

 

[Fitter30]

With 50/50 ( know it illegal) there isn't any soft solder easier to fill a loose fitting cup or cap. No lead, 95/5 or staybrite 8 have to watch your heat very carefully because the temp range is so much smaller than 50/50 to work with, without flowing like water.
Other than a fitting brush only use open weave sand cloth just seems to be easier for me.