So my family tugged on the hose out the front of our house one to many times and the copper pipe the tap is connected to developed a tiny crack. To save myself the trouble of a plumber I decided to borrow one of those little propane torches and redo the joint that cracked.
Propane wasn't hot enough and only just melted 10% silver braze so I went and got MAP gas for the torch instead. As I understand this should be hot enough. The braze melts fine but solidifies as soon as it touches the pipe and refuses to wet it.
Any tips?
>>917993
I should have specified, this is MAP/air
>>917993
>refuses to wet
Flux?
>>917999
Flux won't help the problem of the braze solidifying as soon as it touches the pipe.
https://www.youtube.com/watch?v=07ODV2Bdqow
>>917993
Surface is prolly not getting hot enough to allow the braze to take because of the water behind it acting like a heat sink. Is there a way to empty the pipe? Maybe turn off the main tap and see if the excess leaks out through the crack? If all else fails maybe open every other tap in the house then use a hose fitting to blow into the tap, pushing the water back through the system enough to clear the crack?
>>918002
That's oxyfuel.
>>918005
The pipe is empty and only about 10mm in diameter
>>918007
Well shit.
You have prepped the surface back to shiny bright metal with some steel wool or sandpaper I assume? Short of the water that's literally all I can think of that would prevent flow at this point.
>>918009
I used a steel brush, but yes, I did.
The braze shouldn't be solidfiying as soon as it touches the pipe - it should be melting BY touching the pipe.
Heat the pipe, not the braze. Touch the rod to the side of the pipe opposite the torch, out of the flame jet - if it doesn't melt by touching the pipe for a few seconds, the pipe isn't hot enough.
>>918017
This.
>>918017
Yeah this,
Tips:
-Get rid of all water out of the pipework, otherwise soldering will be impossible.
-Use some sort of heat shield behind where you are blowing the flame, it will focus more heat onto the pipe.
-clean where you want the solder to run back to bare metal, it will flow alot better, same effect as flux.
-heat a larger area of the pipe surrounding where you want to solder before focusing on the spot, this will reduce the heat being 'sucked away' from the spot.
Failing welding, try a compression union/repair coupling.
>>918017
I'm not familiar with OP's burner, but at least my wimpy propane blow torch has difficulties producing enough heat (watts, not degrees) to braze any non-tiny copper pieces and it often takes quite a lot of time to reach the brazing temp.
>>918033
Keep the torch on the pipe as you wipe the join
If it solidifies it's because its not dry enough, how well did you drain it out?
I did a fix under a bathroom floor once that took a whole day just to get the pipe dry enough because of the angle of the run little drops kept appearing from nowhere. In the end I said fuck it and jammed some shit paper down the pipe, luckily there was enough pressure to push it out after into a vertical section that was a breeze to solder because water obeys gravity.
If the pipe sounds like an empty kettle when you heat it then its not dry enough.
>>918058
Use a shop vac to empty the pipes. You can do it from outside even. Just find a tap and suck it all out.
>>917993
why the dickens are you brazing instead of soldering?
>>917993
You have to get the water out first. all of it. and use lead free solder, not silver. propane should be plenty hot for soldering copper. hell, a butane torch lighter is enough to solder copper.
>guy cant heat one of the most thermally conductive metals to 190C with propane.
only on /diy/
>>918107
>You have to get the water out first
Why are you even posting when you haven't read the thread?
>>918058
Next time use bread in the pipe instead.
Keeps the soldering area dry and smells like toast. Instantly liquifies when hit with water and will go through most taps no problem.
>>918171
mmmmmmmmmmmm thanks anon that sounds delicious
>>918171
Works like a charm. "White" bread will pack into a tighter ball for plugging 3/4" copper.
>>918086
This so much.
I've only ever seen people braze with oxygen/acetylene.
OP listen to me I know what I'm talking about. MAP gas isnt enough for braze and oxy acetylene will melt holes in the copper in an untrained hand. Just use aceteylene. But anyways why not solder solder should be enough and yes water can't be in the pipe when soldering.
I'm glad I still have 2 cans of the real discontinued MAPP gas. i save it for any big brass valves I have to do
>>918171
Fuck I wish I had known about this before my last soldering job.
>>919753
It's called a"tinker's dam"
>>919753
Shop vac is way better. A little bit of bread won't work and you'll keep stuffing it and eventually be worried you have stuffed it too much. Shop vac just sucks it all out, nothing to drip in there slowly.
>>919775
yes ok but if i don't own a wet vac then the bread is kind of a good idea
>>919775
Fair enough. Problem was that where I was soldering was literally at the lowest point in the house so getting all the water out would have been impossible. Somehow I managed it though after waiting a few hours for it all to drain out and opening all the faucets upstairs.
>>918017
This.
I use either a regular one with MAP or for tight spaces Oxygen/MAP cause I can make the flame really small and hot in tight spaces. I had to do this over my stack washer as the pipe developed a leak after a bend cracked
MAP gas should be perfectly fine for soldering, i replaced a spigot on 1/2" copper pipe. brazing is out of the question for domestic low pressure water lines. using an acid flux will help a ton for the solder to flow. the issue might be you are heating up just one spot of the pipe when you need to heat up about an inch on both sides of the crack. when its hot enough just back the flame away a bit and the solder should flow fine.
>>917993
>propane wasn't hot enough
No. It's something you're doing that's wrong.
Brazing needs a Max of about 450degC to melt most solders used with copper.
Most propane torches burn at a minimum of 1000degC.
If you're not confident use pushfit brass fittings and brass unions.
>>921140
If you still insist on soldering the joints, replace the fittings for solder ring fittings. The solder is within the fitting so all you have to do is push fit and heat up until the solder melts.
>>918086
who the hell uses silver braze on copper water pipe?
