Failing copper joins during soldering

[bawldiggle]

I am re-plumbing our 70 year old house with new copper pipe and fittings.

The underfloor crawl space is about 16inches (40cms) so access is a challenge.
I am a human ferret -- luckily only very slight build.​

When I started getting too many joint failures and soaked to the skin I changed my process to assembling manifolds in my workshop then making final connections under the floor. (Thankfully it is mid summer here)

Some of the final connections are failing/leaking and in some instances are not even structurally sound.
When I melt/pull the joins apart the failed joins are black on the pipe, not a sign of any solder.
I am using (water soluble) flux for lead less-solder and using lead-less solder (roll of coreless lead-less solder)
- using abrasive plumbers tape on outside of pipe and fittings brush prep in copper fittings.
- liberal use of flux in fittings and and on pipe -- before assembling ready to solder.
- using MAP Gas which I know is extremely hot and potentially overkill to melt solder.
- because of access problems I cannot get the heat behind the fittings, only from one side because of close proximity to bearers, joists and flooring.
- and I simply cannot move quick enough to new positions to try and spread more heat. Overhead soldering is not easy and potentially a risk for personal burns (none so far)

This is my first experience with lead-less solder.
I have plumbed out several houses before (using sticks of lead solder) but never tight access
This current project has me baffled -- and overhead soldering is not easy.
Here in OZ lead solder is still the national accepted standard.​

Q1: Is leaded solder easier to apply and more predictable than lead-less solder. ?

I wonder if my problem might be too much heat in a short time with MAP gas on high or not enough solder available on top of the fitting when soldering over head
- I cannot see the top of overhead fittings so I am never sure if the solder-wire is on the edge of the capillary gap or not
- (I could do with a third arm at times, but alas I only have two hands )
- even soldering both ends of a copper fitting is a challenge because of cramped work space
- I guess my question is would I be better of with a stick of solder rather than the thinner rolled solder.
- I bend a hook in the end of the rolled lead-less solder to start the solder flow on top of the fitting/joint -- and heat the fitting to apply the solder.
- I take the heat off the join while applying the solder
- most of the joins by previous plumbers are covered in solder, not as neat as my joins, but frankly I don't care what the joins look like ... as long as they don't leak and are structurally sound

Lead-less solder and flux are all new
- (my leaded solder flux is about 12 years old - the greasy type of flux for lead soft solder)

There are 3 joints in very awkward locations that are giving me grief.
- in frustration I used 2 straight push-on (for copper) connectors
- push-ons are 10 times the cost of soldered copper fittings.
- the third fitting is presently isolated (the push-on caps for copper do have their use)

She-who-must-be-obeyed is getting impatient for her refurbished laundry
- the upgrade revealed a lot of water supply problems ... I assume by qualified plumbers.

I would be very grateful for any help -- thank you

 

[Matt30]

Can you post a few pictures of some of your joints?

 

[Matt30]

Also, are you trying to solder as you go? Or piecing everything together and soldering all at once? Any water getting into the pipes? Could you be getting your hands on the pipe ends after they been fluxed?

 

[Mr_David]

you don't need a liberal amount of flux. Just a thin coat

Soldering is like cooking. Easy on the heat. You only need about 350 F or so to melt solder. flux will burn before you get the pipe in the fitting up to temp.
I use a torch with an adjustable flame. If you don't have, just throttle the trigger with finger pressure. Don't hold the flame in one spot. If it's just 1/2" and 3/4" you don't need a lot of heat. if you have water then you got a problem. There are a lot of videos on YT. Trick is finding the right one.

The pipe inside the fitting takes a little longer to get to solder melting point than the fitting. To much heat and you burn the flux before the pipe gets to temp. Like cooking and egg. Cook it! Don't burn it.

 

[bawldiggle]

@Matt30
- thank you for your response

Photgraphs!

I will try, after I send this post

... are you trying to solder as you go ... or piecing everything together and soldering all at once?

Long runs (2-3metres) solder as I go.
- test with water after final connections

At first I tried a complex assemble/solder in the confined space and solder up to 12 or more joins
- but that required a contraption of wires to hold it all together
- too many failures
Then tried prefabricating manifolds in my workshop
- I made up a pressure tester for manifolds (water) before attempting an install
- then connect/solder the prefabricated manifold to the main line.

Pushon fittings "caps" are perfect for pressure testing -- and the caps are easily removed​

One install failure was at the end of a completely dry manifold (last, not first join)
- access is a night mare

I also suspect MAP gas is so hot the pipe/fittings retain the heat and if anything moves other still hot joins are compromised. My LP gas bottle is not self lighing.
- cramped access makes using LP gas a very busy exercise with gas bottle, lighter and solder.
- it could be worse if I had a dog.

Any water getting into the pipes?

Yes. after turning on the water supply. Prefabricated manifolds are OK but the final insitu connections leak
- ie, soldered insitu in the confined space
- pipe lines are dead level so hard to drain, 4metre (12ft runs)

It has crossed my mind that because the flux is water soluble ... you raise a good point.
- "if pipe contains any water it will dissolve the (water soluble) flux"
- I have tried heating the pipe to evaporate any water, but I just get a lot of steam,
I also read to stuff some soft bread up the pipe to absorb any water (not tried yet)
- obviously whole grain wont work (cannot lose my sense of humour)

I do have an old "pot" of greasy flux for lead/tin solder
- I know it doesn't wash off
- maybe I should try a lead-solder with the appropriate (greasy) flux ?

Could you be getting your hands on the pipe ends after they been fluxed?

No ! I am anal about "clean"

Thank you
- now to take some photos

 

[bawldiggle]

@ Mr_David

Yes your images are what I am getting
Are you suggesting I adjust the MAP gas burner down to about 1inch of blue flame or less. I am soldering 1/2 inch copper.
- this is my first experience with MAP gas, so maybe I am over-heating the work. ?

Before I started this project I rejected using my ancient (new) brass fittings
- require to much heat to bring the brass upto temperature, and maybe too hot -- cooking/burning the flux.
- I have used copper fittings only on this project

 

[Mr_David]

Steam is your enemy. I had the same problem when I was a rookie. Under a house , muddy, long crawl. First time I stuffed bread into a line....... wait I already wrote that once here before, somewhere>

Never heard that one before. But you don't want to leave it in.

White bread , no crust, is a more common trick of the trade.

First time I did it was in a crawl under a house. Stuffed it good.
Made repair.
Turned water back on.
NO water downstream of repair.
To much bread. Had to cut repair and dig out the bread.
Try again.
Not so much bread next time around.

In a jam I installed a tee with a female adapter. This will allow steam to escape. use a HOT torch farther down the line to boil out the water. Then turn down the flame and solder the joint. When all done screw in a brass plug and call it a day

 

[bawldiggle]

Hi Mr_David

I tried wholemeal bread with lots of butter, chicken, avocado and plenty of coleslaw dressing. I couldn't fit it in the end of a 1/2 inch pipe ... so I ate it.

I am 3 score + 10 ... I thought I had left grovelling around in the mud a long time ago.
Now I know what plumbers knees are like ... sore !
- buy an old house in retirement and you are never bored ​

The Photographs

I am having problems with forum rules. Ten photos, PDF file is 47 times to big for allowable file size.
- no ZIP nor 7zip allowed, I will have to post images in separate posts

Nope that wont work either, all image files (JPG) are way to big (150kb to 200kb) maximum allowed is 100kb
- 20kb for a PDF is nothing,

I will get back to you

 

[Matt30]

Sounds like steam and pressure build up is causing the issues. I have also used the brass plug or drain cock method to get joints to take

 

[havasu]

bawldiggle, I increased your post count so posting pics should be easy. Also, please keep in mind that uploaded pics from your own computer is the easiest way to post, and we have a built in auto resizer for pics.

 

[Mr_David]

bawldiggle, I increased your post count so posting pics should be easy. Also, please keep in mind that uploaded pics from your own computer is the easiest way to post, and we have a built in auto resizer for pics.

Can you bump my post count up to Oh let's say 5k ?




JK



Wow. You currently have 6,998

 

[bawldiggle]

Thank you havasu

I checked my pics sizes Bytes + dimensions. They were way over size.
- I also attempted a PDF with just pics but it was too large.

Now (3:15pm our local time) is first chance I have had to think about the soldering problem. About to fiddle with pic sizes again and I will post.

Thanks again to all for your patience

 

[havasu]

Just download the pic. It will adjust to a size preset for our forum.

 

[bawldiggle]

My pics -- of the problem.
- my apologies for poor quality pics under floor very cramped confined space.
Pic_01


Pic_02


Pic_03


Pic_04
Plumbing has to be up high, because I have to get into underfloor of the wet room
- ie the black void in distance (ground to bearer 14inches)
- some turkey cut a hole in the floor, cut off bearer and two joists, but did not support "left overs". Floor is a trampoline with 18mm (3/4") compressed (asbestos) sheet floor



Pic_05


Pic_06


Pic_07


Pic_08


Pic_09


Pic_10


Thank you

 

[bawldiggle]

Just read a thread Soldering copper pipe in tight location- Help Needed Pics included dated Sept-2012.

johnjh2o post has got me thinking.

Butane/LPG is no where near as hot as MAP gas ?

I suspect the failed dry joint is the result of too much heat (for too long).
- my LP bottle is not a self igniter (but my MAP gas is a click and go)
- this is the gas I am using (Made in USA)


... also ...
Steam is my enemy !

The "T" with a female adaptor ?
- we use different names for plumbing components in OZ (down under)
- I am not sure what you mean ?
- if I solder a T into the line at the lowest point in the line, with the leg of the T down
- and include a threaded nipple (capillary one end/ thread at other end) on the end of the T-leg (down)

Q: T leg up or down ?
- how do you solder the T into place if water is sabotaging the original intended joint. ?
- would a mechanical union (not nut+olive) be a better setup, then maybe steam would have a better escape route.
- I do see the great advantage of a threaded cap in the leg of the T. and the lowest point in the line
- I try to remove a washer from the highest point in the line (usually shower) to allow water to drain back down the line PLUS allow for expanding heated air in the pipe.

40 years ago it took me several hours to figure out why my joins were sliding off while hot -- hotter air expands.
- one of my Homer moments

 

[Matt30]

If you put the tee facing down it will give you a way to drain the line if you have more soldering issues. I also use a shop-vac to suck the line dry

 

[bawldiggle]

Thanks Matt30

I was considering compressed air to clear a line but assumed too much pressure into the instant hot water unit (gas hot water) might compromise the heat exchanger. ie a lot of energy in a burst of compressed air. ?

I have a commercial wet-vac -- your idea is a good one -- but alas the vac is taller than the crawl space, and on its side the vac has a safety cut out.

The T drains are the obvious answer, wish I had known about it before I even started the project. Well at least I now know. Cheap insurance at the start of the job rather than retro Tees into a wet line.
I can see I will have to shut the whole hot system down and drain the lot including the heat exchanger. (There is only a stop-cock on the line in)
-----

I am still unsure about the type of gas to use?
The MAP gas I am using is perfect for (hard) silver soldering, so it is reaching somewhere around 1100°C-1400°C and I read somewhere that the MAP I am using will reach in excess of 2000°C which LP gas is incapable of. (Correct me if I am wrong)

• I have managed to terminate off very wet old (eventually to be abandoned) lines with Silver solder.
By heating the end of the pipe, crushing it, and silver soldering the remaining gap.
Cannot do it with soft solder
• somewhere I read, heat required for silver solder is extreme and anneals the copper pipe, possibly creating possible stress sites if there is a lot of movement in the pipe over time (especially applicable to hot water expansion/contraction with normal use
​

Where I live the coldest ambient temperatures is about 8°C (46°F) so we don't have problems with freezing.

Does my picture in post #17 help identify the type of gas I am using ?
- maybe my "descriptions" ... MAP and LP/LPG are different to what is familiar to you. (I am half a world away, down under)

In my post #15 Pic_05 you can see the top of my LP gas burner.
(It does not have self ignition nor a trigger to control the flame, I need two hands to adjust/terminate the LP flame)
My suspicion is the MAP is just way too hot even when adjusted "down"

I would appreciate any thoughts on the gas I am using.
- would propane/LP (?) be a gentler approach ?

I have yet to meet a plumber or plumbing supplier (here in OZ) who has heard of fitting brushes
- this is what I am up against,
- and inexperienced (non plumbers) behind the counter ... don't get me started.
- my brother lives in Massachusetts, so he mails me goodies that I find on the internet.

I really appreciate the help I am getting on this forum

 

[Matt30]

Soldering is all about torch control. You gotta know when you have enough heat. I use map gas all the time because I can be soldering on one call, and need to braze pipe on the next. I have also soldered like 10,000 joints, but my point is map gas will work for you, it just takes practice. Once solder starts to flow, back the heat away some, and let the joint set up before you move the pipe at all

 

[bawldiggle]

Soldering is all about torch control. You gotta know when you have enough heat. I use map gas all the time because I can be soldering on one call, and need to braze pipe on the next. I have also soldered like 10,000 joints, but my point is map gas will work for you, it just takes practice. Once solder starts to flow, back the heat away some, and let the joint set up before you move the pipe at all

I will have to be more patient.
In the confined space, so many times I have bumped a pipe and compromised the just finished join.

I also suspect the MAP gas is heating more material, keeping joints hot and at risk of failure for longer. Waiting for the work to cool is like watching paint dry.

This confined space work is more for the younger bodies.
- I was a building contacting for 40 years ... one day I will retire !

Thank you for hanging in there with me, much appreciated.
- when this plumbing project is over I will report back the successes here

 

[Mr_David]

put the vacuum on a fixture/faucet upstream and suck the water back.

make sure the new valve is open. That way any moisture can't build up steam pressure.

Female fitting?? Okay. When do they teach kids in school about the difference in genders?
Male goes into Female, By design. Not so true for some.

Look at the pictures. Can you tell which is Female and which is Male?

How do you call them?