How to drain this for soldering?

[AndyB7]

I'm trying to solder a copper/pex adapter for "Shower 1" on the cold pipe at (X) and despite doing several other joints successfully, this one just won't take. I suspect residual water is the culprit but on my last (second) attempt I was confident I had dried everything out by a combination of blowing and sucking from various points. The solder joint had capillary action and seemed solid when cooled (I couldn't twist it off) but alas, it did not stand up to water pressure.

1) Firstly, does my description of the failed joint sound like it was caused by water or would it have not even passed the stress test? (It's possible I burned off the flux on this one and I had actually got the water out ok after all. I got dark smoke before the solder would melt - is that the flux failing?

2) To make sure on my next attempt, how would you approach draining/drying this part of the system (i.e. what valves open/closed and blow/suck from which points). I don't want the expense of a JetSwet for just one joint and I really don't like/trust the idea of stuffing bread in there if avoidable.

In the diagram, fittings numbered "1" are in the bathroom I'm working on, and those numbered "2" are in the adjoining bathroom. There is no other water piping on this floor.

The shut off for Toilet 1 is seized open so I'd rather not muscle that and add to my problems right now.

Re: technique, I am a rank amateur but have learned the basics from instruction: Clean thoroughly until shiny, don't handle, flux x 2, heat fitting only, test for readiness with solder tip, clean up afterwards).

Profound thanks in advance. I feel I may have bit off a bit more than I can chew but I'm too close to quit.

 

[Reach4]

Are you saying that the place you are trying to solder is not at a higher altitude than the toilet 1 drain valve, but the sink 2 and sink 1 stop valves are higher?

Is there room to put a compression valve on there?

 

[Sponsor]

 

[AndyB7]

Are you saying that the place you are trying to solder is not at a higher altitude than the toilet 1 drain valve, but the sink 2 and sink 1 stop valves are higher?

Yes, correct.

Is there room to put a compression valve on there?

Would that be considered safe in an enclosed location? I suppose I could access it by cutting a panel into the drywall behind it were it ever necessary. If so, I could maybe make that work. I don't have enough room right now - the pipe is only just poking out of the stud which is also making soldering very tricky so I was already considering cutting out the bottom section of stud (non load-bearing wall) and then installing support for it once the pipe was done. Then I could use This?

 

[Reach4]

Yes, compression is safe for an enclosed location. Some worry about over-tightening, and I worry about under-tightening. Yes, that adapter should work. You would do well to add some pipe dope as lube, and maybe (maybe not) help beyond its lubrication ability.

But I am not confident about you putting compression over the failed soldering. So if you cannot cut back to clean pipe, I would try soldering again.

Is that pipe you are trying to solder vertical or horizontal? If vertical, I am thinking of inserting some 3/8 inch OD tubing into the pipe, and sucking on the other end with your wet vac.

If horizontal, sounds like it might be harder to clear of water.

 

[AndyB7]

Yes, compression is safe for an enclosed location. Some worry about over-tightening, and I worry about under-tightening. Yes, that adapter should work. You would do well to add some pipe dope as lube, and maybe (maybe not) help beyond its lubrication ability.

But I am not confident about you putting compression over the failed soldering. So if you cannot cut back to clean pipe, I would try soldering again.

Is that pipe you are trying to solder vertical or horizontal? If vertical, I am thinking of inserting some 3/8 inch OD tubing into the pipe, and sucking on the other end with your wet vac.

If horizontal, sounds like it might be harder to clear of water.

It's horizontal and at the lowest point on that floor so I'm dealing with any water that may come from any of the 5 pictured fixtures. The only way to cut the pipe back would be to remove and repair the stud later. After already spending hours trying and failing to drain the pipes by blowing/sucking from any point I can think of, I am loathe to try soldering again, as I now feel like all the re-cleaning might reduce the O/D of the available pipe and give cause for the capillary action to fail. Seems like no clear winner.

I've attached a pic of the culprit - currently with a sharkbite cap on. (Please excuse the scorched stud. I was trying to use a sheet of metal as a heat shield but it wasn't up to it - I since bought the proper welding blanket).

 

[GReynolds929]

When heating a joint you should apply heat evenly to the pipe first and then the fitting. Do not let the flame just sit in one spot.

 

[Reach4]

I've attached a pic of the culprit - currently with a sharkbite cap on.

This water is for a shower? How about putting on a Sharkbite elbow instead of the cap?

 

[AndyB7]

This water is for a shower? How about putting on a Sharkbite elbow instead of the cap?

Yes, it's a shower.

Re Shark Bite, I can't get past my anxiety of installing one where I can't see or access it. Reasons:
1) Even professionals seem split down the middle on the subject. I know they're code compliant (Ontario) but if that's the case, why do so many experts warn against them in enclosed spaces? Do you think this is just anecdotal and/or resistance to change?
2) I already sanded the hell out of the pipe in my attempts to solder so would the 'O' ring seat perfectly now? You already stated your concern re a traditional compression fitting in this regard - does the same not apply to push-fit?
3) I just had an 'O' ring fail in an old shower head which was easily replaced, so I imagine that's possible in a shark bite too, eventually?
4) I'm not sure how to interpret my local building code re compression fittings (i.e. how to I secure the copper and pex sides of the fitting in compliance with this clause).

 

[AndyB7]

When heating a joint you should apply heat evenly to the pipe first and then the fitting. Do not let the flame just sit in one spot.

Thanks. I just did some more practice runs and focused the heat on the pex barb instead of the solder side of the fitting - my thinking being that this would conduct heat evenly to all parts of the joint area. My earlier attempts heating pipe and fitting seemed to burn off the flux (dark smoke) before I got the solder to melt. My tests are holding up to 62PSI (water hose) so I think I'm ready to take another shot at the house pipe if I can sort out getting the pipe dry first.

 

[Reach4]

Are you using "tinning flux"? That works better I think. I like Oatey No. 95. https://www.homedepot.com/p/Oatey-1-7-oz-Lead-Free-Solder-Tinning-Flux-Paste-303742/100347302 Others may like the water-soluble types that are also available as tinning flux.

Also use silver-bearing solder https://www.oatey.com/faqs-blog-videos-case-studies/blog/what-are-the-different-types-of-solder

https://www.homedepot.com/pep/Oatey-Safe-Flo-1-oz-Lead-Free-Silver-Solder-Wire-530612/100210902

 

[AndyB7]

Are you using "tinning flux"? That works better I think. I like Oatey No. 95. https://www.homedepot.com/p/Oatey-1-7-oz-Lead-Free-Solder-Tinning-Flux-Paste-303742/100347302 Others may like the water-soluble types that are also available as tinning flux.

Also use silver-bearing solder https://www.oatey.com/faqs-blog-videos-case-studies/blog/what-are-the-different-types-of-solder

https://www.homedepot.com/pep/Oatey-Safe-Flo-1-oz-Lead-Free-Silver-Solder-Wire-530612/100210902

I bought these together as a 'plumbing solder' kit from HD. I figured as a newbie, buying them together was good insurance that they were compatible with each other. I seem to be getting success with my test joints so gonna have one more crack at soldering the problem joint tomorrow. If I get it as dry as I know how and follow the same steps I'm hoping to get it done cos I just can't see an alternative that works. My next challenge is to get the **** Sharkbite off as I just realized it's too close to the stud to get the tool behind! Talk about a learning curve lol.

 

[Reach4]

I would upgrade. The non-tinning and non-silver can work well, but I want the best edge I can get.

https://www.homedepot.ca/product/oatey-no-95-lead-free-tinning-flux-1-7-oz/1001681850

https://www.homedepot.ca/product/harris-327790-3-oz-plumbing-solder/1000154007

Removal tongs look like they could still be a problem to use. https://www.sharkbite.com/us/en/brass-push-to-connect/tools/disconnect-tongs looks like it would still be a problem.

 

[Bgard]

Clean and prep the pipe and fitting, make sure the pipe and fitting are free of ANY tarnish or corrosion, sand and wipe with cloth, flux pipe and fitting, then take a piece of white bread and stuff it into the pipe, pack it in as far away from the joint as possible, pack it in tight, then quickly solder the joint, the bread will soak up the trickle of water, ANY water at the joint will make the solder joint fail. The bread will absorb the water and keep it away from the joint, when the water is turned back on the bread will devolve away and be washed out of the pipe. Cleanliness of the pipe and fitting cannot be stressed enough, any dirty spot will cause it to fail!

 

[AndyB7]

In case this helps anyone else, these are the steps that led to a successful draining for this scenario

-Water off
-Open ALL valves and let drain
-Close all valves on top floor only, except for Sink1 (first in line) and Toilet2 (last in line)
-Attach a pump to the Sink1 faucet and a vacuum to the Toilet2 inlet (using clear tubing).
-Let both rip for 5 minutes then rest for 5 minutes (in case anything was draining back in from somewhere)
-Repeat previous step until no water visible in clear tube during suction.
-For belt and braces I also used the bread trick. I was not coming back to this one lol.

Also, if you screw up like me and put a sharkbite cap too close to a stud so the removal tool won't fit, I found that my very thin Pex Go/No Go gague worked a treat. It was close enough in diameter and so made contact at the necessary points (although I will write off that sharkbite fitting, just to be safe)

Thanks to anyone who pitched in.

 

[Reach4]

-Attach a pump to the Sink1 faucet

An air pump (compressor), right?

 

[JohnCT]

Regarding the Bites in confined (inaccessible) spaces, I confess I would never use one there, but they *are* code allowed in most places. AFAIK, the only way they fail is when not installed properly, and that means making sure the pipe is deburred and smoothed. If you sanded, that's fine as long as it's not with 80 grit. If so, just sand with 400 until smooth. Also, they can blow off if not inserted fully. Mark the pipe and fully seat the Bite to the line.

I suspect a lot of the stories of SB failures are made up by people who don't want amateurs doing minor (or even major) plumbing repairs. I used several in my basement as a temporary fix until I got around to sweating them properly, but never got back to them. The are 10 years old and dry as your grand daddy's scalp. I *do* however check on them whenever I'm in the basement because I still don't fully trust them!

John

 

[AndyB7]

An air pump (compressor), right?

Actually no. The only compressor I have is a monster in the garage that Mrs B would not appreciate snorting away in the master en suite lol. It was actually a little thing for blowing up air mattresses but it did the job for a short horizontal run.

 

[Fitter30]

Have a slice of bread or two? Smash the bread like your making a snake out of clay jam into the pipe and soldier it. When your done after it cools water pressure will push it out. A drop of water will screw up a joint.

 

[AndyB7]

Regarding the Bites in confined (inaccessible) spaces, I confess I would never use one there, but they *are* code allowed in most places. AFAIK, the only way they fail is when not installed properly, and that means making sure the pipe is deburred and smoothed. If you sanded, that's fine as long as it's not with 80 grit. If so, just sand with 400 until smooth. Also, they can blow off if not inserted fully. Mark the pipe and fully seat the Bite to the line.

I suspect a lot of the stories of SB failures are made up by people who don't want amateurs doing minor (or even major) plumbing repairs. I used several in my basement as a temporary fix until I got around to sweating them properly, but never got back to them. The are 10 years old and dry as your grand daddy's scalp. I *do* however check on them whenever I'm in the basement because I still don't fully trust them!

John

Interesting. I suspect you are right about some professionals fearing loss of business (quite understandably) as more accessible solutions come to market. If this last attempt at soldering had failed I was going to bite the bullet and use one anyway, sanding with low grit to reverse the effect of the earlier, coarser sanding, so I'm glad to hear you confirm that approach in case it comes up in future. Thankfully, the sweat joints are holding nicely so I can put this behind me and crack on.

 

[AndyB7]

Have a slice of bread or two? Smash the bread like your making a snake out of clay jam into the pipe and soldier it. When your done after it cools water pressure will push it out.

Thanks, I'd read that and as well as doing a better job of draining the system, I did that as well as an insurance policy. Joints are holding. Happy boy.